http://git-wip-us.apache.org/repos/asf/polygene-website/blob/ba3a0fac/content/java/develop/glossary.html ---------------------------------------------------------------------- diff --git a/content/java/develop/glossary.html b/content/java/develop/glossary.html new file mode 100644 index 0000000..f11e7a1 --- /dev/null +++ b/content/java/develop/glossary.html @@ -0,0 +1,257 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Glossary </title><link rel="stylesheet" type="text/css" href="css/style.css" /><meta name="generator" content="DocBook XSL Stylesheets V1.76.1" /><link rel="home" href="index.html" title="" /><link rel="up" href="index.html" title="" /><link rel="prev" href="tools-envisage.html" title="Envisage" /> + + +<!-- favicon --> + +<link rel="shortcut icon" href="http://polygene.apache.org/favicon.ico"; type="image/vnd.microsoft.icon" /> +<link rel="icon" href="http://polygene.apache.org/favicon.ico"; type="image/x-icon" /> + +<!-- style --> + +<link href="css/shCore.css" rel="stylesheet" type="text/css" /> +<link href="css/shCoreEclipse.css" rel="stylesheet" type="text/css" /> +<link href="css/shThemeEclipse.css" rel="stylesheet" type="text/css" /> +<link href="css/polygene.css" rel="stylesheet" type="text/css" /> + +<!-- Syntax Highlighter --> + +<script type="text/javascript" src="js/shCore.js"></script> +<script type="text/javascript" src="js/shBrushJava.js"></script> +<script type="text/javascript" src="js/shBrushScala.js"></script> +<script type="text/javascript" src="js/shBrushJScript.js"></script> +<script type="text/javascript" src="js/shBrushBash.js"></script> +<script type="text/javascript" src="js/shBrushPlain.js"></script> +<script type="text/javascript" src="js/shBrushXml.js"></script> +<script type="text/javascript" src="js/shBrushGroovy.js"></script> +<script type="text/javascript" src="js/shBrushPython.js"></script> +<script type="text/javascript" src="js/shBrushRuby.js"></script> +<script type="text/javascript" src="js/shBrushCSharp.js"></script> + +<script type="text/javascript"> + SyntaxHighlighter.defaults['tab-size'] = 4; + SyntaxHighlighter.defaults['gutter'] = false; + SyntaxHighlighter.defaults['toolbar'] = false; + SyntaxHighlighter.all() +</script> + +<!-- JQuery --> + +<script type="text/javascript" src="js/jquery-1.6.4.min.js"></script> + +<!-- Image Scaler --> + +<script type="text/javascript" src="js/imagescaler.js"></script> + +<!-- Table Styler --> + +<script type="text/javascript" src="js/tablestyler.js"></script> + +<!-- Apache Polygene WebSite Progressive Enhancement --> + +<link href="css/progressive-enhancement.css" rel="stylesheet" type="text/css" /> +<script type="text/javascript" src="js/jquery.scrollTo-1.4.2.js"></script> +<script type="text/javascript" src="js/progressive-enhancement.js"></script> + +<!-- Analytics --> + <script type="text/javascript"> + var _gaq = _gaq || []; + _gaq.push(['_setAccount', 'UA-62007352-1']); + _gaq.push(['_trackPageview']); + + (function() { + var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; + ga.src = ('https:' == document.location.protocol ? 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So in true DDD-style +ubiquitous language, we are here listing the definitions of the terms and concepts that are being used.</p><dl><dt> +<a id="def-abstract-mixin"></a>Abstract Mixin +</dt><dd><p>An Abstract Mixin is an implementation of the <a class="xref" href="glossary.html#def-mixin-type">MixinType</a> interface, but is an abstract class and has not +implemented all the methods.</p><p>The Polygene⢠runtime can use multiple <a class="link" href="glossary.html#def-mixin">Mixins</a> for each <a class="xref" href="glossary.html#def-mixin-type">MixinType</a> interface. It is also possible to let +a <a class="xref" href="glossary.html#def-generic-mixin">Generic Mixin</a> handle the remaining missing methods.</p></dd><dt> +<a id="def-abstract-modifier"></a>Abstract Modifier +</dt><dd><p>Abstract Modifiers are <a class="link" href="glossary.html#def-modifier">Modifiers</a> that do not implement all the methods of the <a class="xref" href="glossary.html#def-mixin-type">MixinType</a> +interface.</p><p>This works essentially in the same manner as the <a class="xref" href="glossary.html#def-abstract-mixin">Abstract Mixin</a>. And the methods that are not implemented +will not be part of the <a class="xref" href="glossary.html#def-invocation-stack">Invocation Stack</a> of those methods.</p></dd><dt> +<a id="def-application"></a>Application +</dt><dd><p>Application is the top level concept handled by the Polygene⢠runtime instance. It holds the information about the +<a class="link" href="glossary.html#def-layer">Layers</a> in the application architecture. See <a class="xref" href="glossary.html#def-structure">Structure</a> for more information.</p><p>There is one and only one Application instance per Polygene⢠Runtime instance.</p></dd><dt> +<a id="def-application-mode"></a>Application Mode +</dt><dd><p>During the Bootstrap phase an <a class="xref" href="glossary.html#def-application">Application</a> is given a Mode that can be <span class="emphasis"><em>test</em></span>, <span class="emphasis"><em>development</em></span>, <span class="emphasis"><em>staging</em></span> or +<span class="emphasis"><em>production</em></span>.</p><p>See <a class="xref" href="core-bootstrap-assembly.html" title="Core Bootstrap">Assembly</a>.</p></dd><dt> +<a id="def-association"></a>Association +</dt><dd><p>An Association is a reference to an <a class="xref" href="glossary.html#def-entitycomposite">Entity Composite</a>.</p><p>References to <a class="link" href="glossary.html#def-entitycomposite">Entities</a> must be maintained in <a class="link" href="glossary.html#def-association">Associations</a>. It is illegal to +define a <a class="xref" href="glossary.html#def-property">Property</a> with an <a class="xref" href="glossary.html#def-entitycomposite">Entity Composite</a> as its type.</p></dd><dt> +<a id="def-composite"></a>Composite +</dt><dd><p>A Composite is an instance of a <a class="xref" href="glossary.html#def-composite-type">Composite Type</a>.</p><p>However, we often speak of Composites when we actually mean CompositeType, similarly as we often speak of objects +when we really are talking of classes in OOP.</p></dd><dt> +<a id="def-composite-context"></a>Composite Context +</dt><dd><p>A Composite Context is a mechanism to separate the state of a <a class="xref" href="glossary.html#def-transientcomposite">TransientComposite</a> across two or more threads. +If a thread modifies a value, only that thread will see the changes, another thread will have its values protected +by the thread boundaries. Use-cases for this include user credentials on which behalf the thread is executing.</p></dd><dt> +<a id="def-composite-metatype"></a>Composite Meta Type +</dt><dd><p>There are 5 Composite Meta Types defined in Polygene, which each share the composition features but have distinct +semantic differences.</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +<a class="xref" href="glossary.html#def-entitycomposite">Entity Composite</a> +</li><li class="listitem"> +<a class="xref" href="glossary.html#def-valuecomposite">ValueComposite</a> +</li><li class="listitem"> +<a class="xref" href="glossary.html#def-servicecomposite">Service composite</a> +</li><li class="listitem"> +<a class="xref" href="glossary.html#def-configurationcomposite">Configuration Composite</a> (subtype of EntityComposite) +</li><li class="listitem"> +<a class="xref" href="glossary.html#def-transientcomposite">TransientComposite</a> +</li></ul></div></dd><dt> +<a id="def-composite-type"></a>Composite Type +</dt><dd><p>CompositeType is the Java interface that declares the composition, from which <a class="xref" href="glossary.html#def-composite">Composite</a> instances can be +created.</p><p>Composite Type interfaces must be a sub-type of one of the 5 <a class="link" href="glossary.html#def-composite-metatype">Composite Meta Types</a> defined in +Polygene⢠otherwise it can not be instantiated.</p></dd><dt> +<a id="def-concern"></a>Concern +</dt><dd><p>A concern is a stateless <a class="xref" href="glossary.html#def-fragment">Fragment</a>, shared between invocations, that acts as an interceptor of the call to +the <a class="xref" href="glossary.html#def-mixin">Mixin</a>. The Concern is a Java class, that either implements the <a class="xref" href="glossary.html#def-mixin-type">MixinType</a> it can be used on, or +java.lang.reflect.InvocationHandler which allows it to be used on any arbitrary <a class="xref" href="glossary.html#def-mixin-type">MixinType</a>.</p><p>Concerns have many purposes, but they are not intended to produce side effects (see <a class="xref" href="glossary.html#def-sideeffect">SideEffect</a>). Use-cases +involves;</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +Transaction handling. +</li><li class="listitem"> +Call Tracing. +</li><li class="listitem"> +User security. +</li></ul></div><p>Concerns are established by the use of the @Concerns annotation on composites.</p><p>Concern is one of the 3 kinds of <a class="link" href="glossary.html#def-modifier">Modifiers</a> defined in Polygene.</p></dd><dt> +<a id="def-configurationcomposite"></a>Configuration Composite +</dt><dd><p>Service Composites can have configuration associated to it and that is done via +<a class="link" href="glossary.html#def-configurationcomposite">Configuration Composites</a>, which are a subtype of <a class="xref" href="glossary.html#def-entitycomposite">Entity Composite</a>, as they are +stored permanently in configured Entity Stores. Configuration Composites are also initialized automatically from +properties files first time. Note that on consequent start-ups the properties file is not read, as the configuration is +read from the EntityStore.</p><p>ConfigurationComposite is one of the 5 <a class="link" href="glossary.html#def-composite-metatype">Composite Meta Types</a> defined in Polygene.</p><p>See <a class="xref" href="howto-configure-service.html" title="Configure a Service">Configure a Service</a> to learn how to use Configuration Composites.</p></dd><dt> +<a id="def-constraint"></a>Constraint +</dt><dd><p>Constraints are a kind of validators, which are consulted prior to invoking the method call. Polygene⢠currently only +supports ParameterConstraints on methods and value constraints on <a class="link" href="glossary.html#def-property">Properties</a>, but future versions will +include Constraint types for checking complete method calls and return values.</p><p>See <a class="xref" href="core-api.html#core-api-constraint" title="Constraint">Constraint</a> for better understanding of its details.</p><p>See <a class="xref" href="library-constraints.html" title="Constraints">Constraints Library</a> for ready to use Constraints.</p><p>See <a class="xref" href="howto-create-constraint.html" title="Create a Constraint">Create a Constraint</a> to learn how to write your own Constraints.</p><p>Constraint is one of the 3 kinds of <a class="link" href="glossary.html#def-modifier">Modifiers</a> defined in Polygene.</p></dd><dt> +<a id="def-entitycomposite"></a>Entity Composite +</dt><dd><p>An Entity Composite, or just Entity for short, is a persisted composite with an <a class="xref" href="glossary.html#def-identity">Identity</a>. An entity only has +scope within an <a class="xref" href="glossary.html#def-unitofwork">UnitOfWork</a> and is therefor inherently thread-safe.</p><p>EntityComposite is one of the 5 <a class="link" href="glossary.html#def-composite-metatype">Composite Meta Types</a> defined in Polygene.</p></dd><dt> +<a id="def-fragment"></a>Fragment +</dt><dd><p>A part of the implementation of a <a class="xref" href="glossary.html#def-composite">Composite</a>. There are 4 fragment types:</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +<a class="xref" href="glossary.html#def-mixin">Mixin</a> +</li><li class="listitem"> +<a class="xref" href="glossary.html#def-concern">Concern</a> +</li><li class="listitem"> +<a class="xref" href="glossary.html#def-constraint">Constraint</a> +</li><li class="listitem"> +<a class="xref" href="glossary.html#def-sideeffect">SideEffect</a>. +</li></ul></div></dd><dt> +<a id="def-generic-fragment"></a>Generic Fragment +</dt><dd><p>Generic Fragments are <a class="link" href="glossary.html#def-fragment">Fragments</a> that implements java.lang.reflect.InvocationHandler and potentially +capable of being used for all <a class="link" href="glossary.html#def-mixin-type">MixinTypes</a>. This is the direct opposite of the Typed Fragments, which +implements the <a class="xref" href="glossary.html#def-mixin-type">MixinType</a> interface.</p></dd><dt> +<a id="def-generic-mixin"></a>Generic Mixin +</dt><dd><p>A Generic Mixin implements the java.lang.reflect.InvocationHandler. The invoke() method will be called for all +<a class="xref" href="glossary.html#def-mixin-type">MixinType</a> methods that the <a class="xref" href="glossary.html#def-mixin">Mixin</a> has been matched with, through the matching rules.</p><p>It is potentially possible that the Generic Mixin also implements the <a class="xref" href="glossary.html#def-mixin-type">MixinType</a> interface. In that case, the +concrete methods will be called, but if the <a class="xref" href="glossary.html#def-mixin">Mixin</a> is also an abstract class, then the invoke() method will be +called for the methods that has been match but are not present.</p></dd><dt> +<a id="def-identity"></a>Identity +</dt><dd><p>TODO</p><p>This term has no definition yet. Learn how to contribute in <a class="xref" href="community-docs.html" title="Polygene⢠Documentation">Writing Documentation</a>.</p></dd><dt> +<a id="def-invocation-stack"></a>Invocation Stack +</dt><dd><p>For each method, Polygene⢠will create and re-use an Invocation Stack. It will be built with the sequence of +<a class="link" href="glossary.html#def-modifier">Modifiers</a> and an end-point that will link into the stateful <a class="xref" href="glossary.html#def-mixin">Mixin</a>.</p><p>It is important to recognize that, for memory footprint reasons, Invocation Stacks are shared across +<a class="link" href="glossary.html#def-composite">Composites</a> of the same <a class="xref" href="glossary.html#def-composite-type">Composite Type</a>. They are however thread-safe, in that Polygene⢠will never +bind the same Invocation Stack to more than one <a class="xref" href="glossary.html#def-composite">Composite</a> instance during a method call, but that between method +invocations the <a class="link" href="glossary.html#def-modifier">Modifiers</a> in the Invocation Stack can not assume that it is bound to the same +<a class="xref" href="glossary.html#def-composite">Composite</a> instance. Therefor, <a class="link" href="glossary.html#def-modifier">Modifiers</a> are not expected to keep state between method +invocations, and when it needs to do that, then it should reference a <a class="xref" href="glossary.html#def-mixin">Mixin</a> via the @This annotation. Polygene⢠will +during the binding of the Invocation Stack to the <a class="xref" href="glossary.html#def-composite">Composite</a>, also ensure that all referenced +<a class="link" href="glossary.html#def-mixin">Mixins</a> are correctly injected in the Invocation Stack.</p></dd><dt> +<a id="def-layer"></a>Layer +</dt><dd><p>Polygene⢠promotes a Layered application design, where Layers can only access lower Layers and not higher Layers or Layers at +the same level.</p></dd><dt> +<a id="def-manyassociation"></a>ManyAssociation +</dt><dd><p>TODO</p><p>This term has no definition yet. Learn how to contribute in <a class="xref" href="community-docs.html" title="Polygene⢠Documentation">Writing Documentation</a>.</p></dd><dt> +<a id="def-metainfo"></a>MetaInfo +</dt><dd><p>TODO</p><p>This term has no definition yet. Learn how to contribute in <a class="xref" href="community-docs.html" title="Polygene⢠Documentation">Writing Documentation</a>.</p></dd><dt> +<a id="def-mixin"></a>Mixin +</dt><dd><p>The Mixin is the instance providing the stateful representation of the <a class="xref" href="glossary.html#def-mixin-type">MixinType</a>. This can either be a class +implementing the <a class="xref" href="glossary.html#def-mixin-type">MixinType</a> or a java.lang.reflect.InvocationHandler that is generic to handle any or a subset +of <a class="xref" href="glossary.html#def-mixin-type">MixinType</a>.</p></dd><dt> +<a id="def-mixin-type"></a>MixinType +</dt><dd><p>The MixinType is the static type of a part of the <a class="xref" href="glossary.html#def-composite">Composite</a>. The MixinType is an interface that defines the methods +to be exposed in the <a class="xref" href="glossary.html#def-composite">Composite</a>.</p></dd><dt> +<a id="def-modifier"></a>Modifier +</dt><dd><p>Modifiers are stateless interceptors of method calls, that forms an <a class="xref" href="glossary.html#def-invocation-stack">Invocation Stack</a>. The top of the +<a class="xref" href="glossary.html#def-invocation-stack">Invocation Stack</a> is linked to the <a class="xref" href="glossary.html#def-composite">Composite</a> invocation handler and the bottom of the +<a class="xref" href="glossary.html#def-invocation-stack">Invocation Stack</a> is linked to the <a class="link" href="glossary.html#def-mixin">Mixins</a>. <a class="link" href="glossary.html#def-invocation-stack">Invocation Stacks</a> are shared, +so Modifiers must assume that the member fields will only be valid within a single method invocation.</p><p>There are 3 kinds of Modifiers;</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +<a class="xref" href="glossary.html#def-constraint">Constraint</a> +</li><li class="listitem"> +<a class="xref" href="glossary.html#def-concern">Concern</a> +</li><li class="listitem"> +<a class="xref" href="glossary.html#def-sideeffect">SideEffect</a> +</li></ul></div></dd><dt> +<a id="def-module"></a>Module +</dt><dd><p>Modules defines the scope of the <a class="link" href="glossary.html#def-composite">Composites</a>. Modules are wired with Assemblies, and can expose +<a class="link" href="glossary.html#def-composite">Composites</a> as visible. Non-visible <a class="link" href="glossary.html#def-composite">Composites</a> are not reachable from other Modules.</p></dd><dt> +<a id="def-namedassociation"></a>NamedAssociation +</dt><dd><p>TODO</p><p>This term has no definition yet. Learn how to contribute in <a class="xref" href="community-docs.html" title="Polygene⢠Documentation">Writing Documentation</a>.</p></dd><dt> +<a id="def-private-mixin"></a>Private Mixin +</dt><dd><p>When a @This injection refers to a <a class="xref" href="glossary.html#def-mixin-type">MixinType</a> which is not extended by the <a class="xref" href="glossary.html#def-composite-type">Composite Type</a> the former +becomes a private <a class="xref" href="glossary.html#def-mixin-type">MixinType</a>.</p></dd><dt> +<a id="def-property"></a>Property +</dt><dd><p>TODO</p><p>This term has no definition yet. Learn how to contribute in <a class="xref" href="community-docs.html" title="Polygene⢠Documentation">Writing Documentation</a>.</p><p>See the <a class="xref" href="howto-leverage-properties.html" title="Leverage Properties">Leverage Properties</a> how-to.</p></dd><dt> +<a id="def-servicecomposite"></a>Service Composite +</dt><dd><p>Service Composite is a subtype of <a class="xref" href="glossary.html#def-composite">Composite</a>, and has a range of features built into it.</p><p>ServiceComposite is one of the 5 <a class="link" href="glossary.html#def-composite-metatype">Composite Meta Types</a> defined in Polygene.</p><p>See the <a class="link" href="core-api.html#core-api-service" title="Service Composite">Service Composite chapter</a>.</p></dd><dt> +<a id="def-sideeffect"></a>SideEffect +</dt><dd><p>A side effect is a stateless <a class="xref" href="glossary.html#def-fragment">Fragment</a>, shared between invocations, that acts as an interceptor of the call to +the <a class="xref" href="glossary.html#def-mixin">Mixin</a>. The SideEffect is a Java class, that either implements the <a class="xref" href="glossary.html#def-mixin-type">MixinType</a> it can be used on, or +java.lang.reflect.InvocationHandler which allows it to be used on any arbitrary <a class="xref" href="glossary.html#def-mixin-type">MixinType</a>.</p><p>SideEffects are executed after the completion of the method invocation and therefore cannot change parameters nor +eventually returned object.</p><p>SideEffects have many purposes. Use-cases +involves;</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +Sending emails. +</li><li class="listitem"> +Call Tracing. +</li><li class="listitem"> +Domain side effects modeling. +</li></ul></div><p>SideEffects are established by the use of the @SideEffects annotation on composites.</p><p>SideEffect is one of the 3 kinds of <a class="link" href="glossary.html#def-modifier">Modifiers</a> defined in Polygene.</p></dd><dt> +<a id="def-structure"></a>Structure +</dt><dd><p>Polygene⢠promotes a conventional view of application structure, that computer science has been using for decades.</p><p>The definition is as follows;</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +One <a class="xref" href="glossary.html#def-application">Application</a> per Polygene⢠runtime instance. +</li><li class="listitem"> +One or more <a class="link" href="glossary.html#def-layer">Layers</a> per <a class="xref" href="glossary.html#def-application">Application</a>. +</li><li class="listitem"> +Zero, one or more <a class="link" href="glossary.html#def-module">Modules</a> per <a class="xref" href="glossary.html#def-layer">Layer</a>. +</li><li class="listitem"> +Zero, one or more Assemblies per <a class="xref" href="glossary.html#def-module">Module</a>. +</li></ul></div><p>The principle of this Structure is to assist the programmer to create well modularized applications, that are easily +extended and maintained. Polygene⢠will restrict access between <a class="link" href="glossary.html#def-module">Modules</a>, so that code can only reach +<a class="link" href="glossary.html#def-composite">Composites</a> and Objects in <a class="link" href="glossary.html#def-module">Modules</a> (including itself) of the same or lower +<a class="link" href="glossary.html#def-layer">Layers</a>.</p><p>Each <a class="xref" href="glossary.html#def-layer">Layer</a> has to be declared which lower <a class="link" href="glossary.html#def-layer">Layer(s)</a> it uses, and it is not allowed that a lower +<a class="xref" href="glossary.html#def-layer">Layer</a> uses a higher <a class="xref" href="glossary.html#def-layer">Layer</a>, i.e. cyclic references.</p></dd><dt> +<a id="def-transientcomposite"></a>TransientComposite +</dt><dd><p>TransientComposite is a <a class="xref" href="glossary.html#def-composite-metatype">Composite Meta Type</a> for all other cases. The main characteristics are;</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +It can not be serialized nor persisted. +</li><li class="listitem"> +hashcode/equals are not treated specially and will be delegated to <a class="link" href="glossary.html#def-fragment">Fragment(s)</a> implementing those methods. +</li><li class="listitem"> +It can not be used as a <a class="xref" href="glossary.html#def-property">Property</a> type. +</li></ul></div></dd><dt> +<a id="def-unitofwork"></a>UnitOfWork +</dt><dd><p>TODO</p><p>This term has no definition yet. Learn how to contribute in <a class="xref" href="community-docs.html" title="Polygene⢠Documentation">Writing Documentation</a>.</p></dd><dt> +<a id="def-valuecomposite"></a>ValueComposite +</dt><dd><p>Usage of value objects is one of the most ignored and best return-on-investment the programmer can do. Values are +immutable and can be compared by value instead of memory reference. Concurrency is suddenly not an issue, since either +the value exists or it doesnât, no need for synchronization. Values are typically very easy to test and very robust to +refactoring.</p><p>Polygene⢠defines values as a primary meta type through the ValueComposite, as we think the benefits of values are great. +The ValueComposite is very light-weight compared to the <a class="xref" href="glossary.html#def-entitycomposite">Entity Composite</a>, and its value can still be persisted as +part of an <a class="xref" href="glossary.html#def-entitycomposite">Entity Composite</a> via a <a class="xref" href="glossary.html#def-property">Property</a>.</p><p>The characteristics of a ValueComposite compared to other <a class="link" href="glossary.html#def-composite-metatype">Composite Meta Types</a> are;</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +It is Immutable. +</li><li class="listitem"> +Its equals/hashCode works on the values of the ValueComposite. +</li><li class="listitem"> +Can be used as <a class="xref" href="glossary.html#def-property">Property</a> types, but will not be indexed and searchable. +</li></ul></div></dd></dl></div></div><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="footer"><p> + Copyright © 2015 The Apache Software Foundation, Licensed under the <a href="http://www.apache.org/licenses/"; target="_blank">Apache License, Version 2.0</a>. + <br /><small> + Apache Polygene, Polygene, Apache, the Apache feather logo, and the Apache Polygene project logo are trademarks of The Apache Software Foundation.<br /> + All other marks mentioned may be trademarks or registered trademarks of their respective owners. + </small></p></div></body></html> \ No newline at end of file
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See the <a class="xref" href="howto-depend-on-polygene.html" title="Depend on Polygeneâ¢">Depend on Polygeneâ¢</a> tutorial for details.</p><div class="section" title="Basics"><div class="titlepage"><div><div><h4 class="title"><a id="_basics"></a>Basics</h4></div></div></div><p>First letâs recap the structural requirements of Polygene;</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +There is one and only one Application instance per Polygene⢠Runtime. +</li><li class="listitem"> +Every Application must contain one or more Layers. +</li><li class="listitem"> +All Composites must be declared in one or more Modules. +</li><li class="listitem"> +Each Module belong to a Layer. +</li><li class="listitem"> +Layers are ordered in hierarchies, from simple to complex. +</li><li class="listitem"> +Access to Composites are limited by visibility rules. +</li></ul></div><p>Ok, that was quite a handful. Letâs look at them one by one.</p></div><div class="section" title="Application"><div class="titlepage"><div><div><h4 class="title"><a id="_application"></a>Application</h4></div></div></div><p>The first one means that for each Polygene⢠Runtime you start, there will be exactly one application. As far as we know, Polygene +is fully isolated, meaning there are no static members being populated and such.</p></div><div class="section" title="Layers"><div class="titlepage"><div><div><h4 class="title"><a id="_layers"></a>Layers</h4></div></div></div><p>Layers are the super-structures of an application. We have been talking about them for decades, drawn them on paper and +whiteboards (or even black boards for those old enough), and sometimes organized the codebases along such boundaries. +But, there has been little effort to enforce the Layer mechanism in code, although it is an extremely powerful +construct. First of all it implies directional dependency and a high degree of order, spagetti code is reduced if +successfully implemented. For Polygene, it means that we can restrict access to Composite and Object declarations, so that +higher layers can not reach them incidentally. You can enforce architecture to a high degree. You can require all +creation of composites to go through an exposed Factory, which doesnât require the Composite to be public. And so on. +Layers have hierarchy, i.e. one layer is top of one or more layers, and is below one or more layers, except for the +layers at the top and bottom. You could have disjoint layers, which canât access each other, meaning a couple of layers +that are both the top and bottom.</p></div><div class="section" title="Modules"><div class="titlepage"><div><div><h4 class="title"><a id="_modules"></a>Modules</h4></div></div></div><p>The Module concept has also been around forever. And in Polygene⢠we also makes the Modules explicit. Each Module belong to a +Layer, and for each Module you declare the Composite and Object types for that Module, together with a Visibility rule, +one of; application, layer, module.</p></div><div class="section" title="Visibility"><div class="titlepage"><div><div><h4 class="title"><a id="_visibility"></a>Visibility</h4></div></div></div><p>The Visibility rules are perhaps the most powerful aspect of the above. Visibility is a mechanism that kicks in whenever +a Composite type need to be looked up. It defines both the scoping rules of the client as well as the provider. A lookup +is either a direct reference, such as</p><pre class="programlisting brush: java">UnitOfWork unitOfWork = module.currentUnitOfWork(); +PersonEntity person = unitOfWork.newEntity( PersonEntity.class ); +</pre><p>or an indirect lookup, such as</p><pre class="programlisting brush: java">UnitOfWork unitOfWork = module.currentUnitOfWork(); +Person person = unitOfWork.newEntity( Person.class ); +</pre><p>where it will first map the Person to a reachable PersonEntity. +The algorithm is as follows;</p><div class="itemizedlist"><ul class="itemizedlist"><li class="listitem"> +Look in the callers Module, if there is one and only one Composite type matching, use it. If there are two or more + Composite types matching, then throw an ambiguity exception. If there are zero, proceed to the next step. +</li><li class="listitem"> +Look in all Modules in the callers Layer. If there is one and only one Composite type that matches and is either + Visibility.layer, then use it. If there are two or more Composite types matching, then throw an ambiguity + exception. If there are zero, proceed to the next step. +</li><li class="listitem"> +Look in all Layers that callerâs Layer uses. If there is one and only one Composite type that matches and is + either Visibility.application, then use it. If there are two or more Composite types matching, then throw an + ambiguity exception. If there are zero, proceed to the next step. +</li><li class="listitem"> +Throw a CompositeNotFoundException. +</li></ul></div><p>The underlying principle comes down to Rickardâs "Speaker Analogy", you can hear him (and not the other speakers at the +conference) because you are in the same room. I.e. if something is really close by, it is very likely that this is what +we want to use, and then the search expands outwards.</p></div><div class="section" title="Combining The Above"><div class="titlepage"><div><div><h4 class="title"><a id="_combining_the_above"></a>Combining The Above</h4></div></div></div><p>Ok, that was a whole lot of theory and probably take you more than one read-through to fully get into your veins (slow +acting addiction). +How to structure your code is beyond the scope of this section. If you are an experienced designer, you will have done +that before, and you may have started out with good intentions at times only to find yourself in a spaghetti swamp +later, or perhaps in the also famous "Clear as Clay" or "Ball (bowl?) of Mud". Either way, you need to draw on your +experience and come up with good structure that Polygene⢠lets you enforce.</p><p>So, for the sake of education, we are going to look at an application that consists of many layers, each with a few +modules. See picture below.</p><p>Image of Example of Layers</p><p>Figure 1. Example of Layers</p><p>So, lets see how we code up this bit in the actual code first.</p><pre class="programlisting brush: java">public class Main +{ + private static Energy4Java polygene; + private static Application application; + + public static void main( String[] args ) + throws Exception + { + // Bootstrap Polygene Runtime + // Create a Polygene Runtime + polygene = new Energy4Java(); + + // Instantiate the Application Model. + application = polygene.newApplication( new ApplicationAssembler() + { + public ApplicationAssembly assemble( + ApplicationAssemblyFactory factory ) + throws AssemblyException + { + ApplicationAssembly assembly = + factory.newApplicationAssembly(); + LayerAssembly runtime = createRuntimeLayer( assembly ); + LayerAssembly designer = createDesignerLayer( assembly ); + LayerAssembly domain = createDomainLayer( assembly ); + LayerAssembly messaging= createMessagingLayer( assembly ); + LayerAssembly persistence = createPersistenceLayer( assembly ); + + // declare structure between layers + domain.uses( messaging ); + domain.uses( persistence ); + designer.uses( persistence ); + designer.uses( domain ); + runtime.uses( domain ); + + return assembly; + } + } ); + + // We need to handle shutdown. + installShutdownHook(); + + // Activate the Application Runtime. + application.activate(); + } + + [...snip...] + +} + +</pre><p>The above is the basic setup on how to structure a real-world applicaton, unless you intend to mess with the +implementations of various Polygene⢠systems (yes there are hooks for that too), but that is definitely beyond the scope of +this tutorial.</p><p>Now, the createXyzLayer() methods were excluded to keep the sample crisp and easy to follow. Letâs take a look at what +it could be to create the Domain Layer.</p><pre class="programlisting brush: java">private static LayerAssembly createDomainLayer( ApplicationAssembly app ) +{ + LayerAssembly layer = app.layer("domain-layer"); + createAccountModule( layer ); + createInventoryModule( layer ); + createReceivablesModule( layer ); + createPayablesModule( layer ); + return layer; +} + +</pre><p>We just call the layerAssembly() method, which will return either an existing Layer with that name or create a new one +if one doesnât already exist, and then delegate to methods for creating the ModuleAssembly instances. In those method +we need to declare which Composites, Entities, Services and Objects that is in each Module.</p><pre class="programlisting brush: java">private static void createAccountModule( LayerAssembly layer ) +{ + ModuleAssembly module = layer.module("account-module"); + + module.entities(AccountEntity.class, EntryEntity.class); + + module.addServices( + AccountRepositoryService.class, + AccountFactoryService.class, + EntryFactoryService.class, + EntryRepositoryService.class + ).visibleIn( Visibility.layer ); +} + +</pre><p>We also need to handle the shutdown case, so in the main() method we have a installShutdownHook() method call. It is +actually very, very simple;</p><pre class="programlisting brush: java">private static void installShutdownHook() +{ + Runtime.getRuntime().addShutdownHook( new Thread( new Runnable() + { + public void run() + { + if( application != null ) + { + try + { + application.passivate(); + } + catch( Exception e ) + { + e.printStackTrace(); + } + } + } + }) ); +} +</pre><p>This concludes this tutorial. We have looked how to get the initial Polygene⢠runtime going, how to declare the assembly +for application model creation and finally the activation of the model itself.</p></div></div><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="footer"><p> + Copyright © 2015 The Apache Software Foundation, Licensed under the <a href="http://www.apache.org/licenses/"; target="_blank">Apache License, Version 2.0</a>. + <br /><small> + Apache Polygene, Polygene, Apache, the Apache feather logo, and the Apache Polygene project logo are trademarks of The Apache Software Foundation.<br /> + All other marks mentioned may be trademarks or registered trademarks of their respective owners. + </small></p></div></body></html> \ No newline at end of file http://git-wip-us.apache.org/repos/asf/polygene-website/blob/ba3a0fac/content/java/develop/howto-configure-service.html ---------------------------------------------------------------------- diff --git a/content/java/develop/howto-configure-service.html b/content/java/develop/howto-configure-service.html new file mode 100644 index 0000000..565bff8 --- /dev/null +++ b/content/java/develop/howto-configure-service.html @@ -0,0 +1,182 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Configure a Service</title><link rel="stylesheet" type="text/css" href="css/style.css" /><meta name="generator" content="DocBook XSL Stylesheets V1.76.1" /><link rel="home" href="index.html" title="" /><link rel="up" href="tutorials.html" title="Tutorials" /><link rel="prev" href="howto-create-entity.html" title="Create an Entity" /><link rel="next" href="howto-invocation-annotation.html" title="Use @Invocation" /> + + +<!-- favicon --> + +<link rel="shortcut icon" href="http://polygene.apache.org/favicon.ico"; type="image/vnd.microsoft.icon" /> +<link rel="icon" href="http://polygene.apache.org/favicon.ico"; type="image/x-icon" /> + +<!-- style --> + +<link href="css/shCore.css" rel="stylesheet" type="text/css" /> +<link href="css/shCoreEclipse.css" rel="stylesheet" type="text/css" /> +<link href="css/shThemeEclipse.css" rel="stylesheet" type="text/css" /> +<link href="css/polygene.css" rel="stylesheet" type="text/css" /> + +<!-- Syntax Highlighter --> + +<script type="text/javascript" src="js/shCore.js"></script> +<script type="text/javascript" src="js/shBrushJava.js"></script> +<script type="text/javascript" src="js/shBrushScala.js"></script> +<script type="text/javascript" src="js/shBrushJScript.js"></script> +<script type="text/javascript" src="js/shBrushBash.js"></script> +<script type="text/javascript" src="js/shBrushPlain.js"></script> +<script type="text/javascript" src="js/shBrushXml.js"></script> +<script type="text/javascript" src="js/shBrushGroovy.js"></script> +<script type="text/javascript" src="js/shBrushPython.js"></script> +<script type="text/javascript" src="js/shBrushRuby.js"></script> +<script type="text/javascript" src="js/shBrushCSharp.js"></script> + +<script type="text/javascript"> + SyntaxHighlighter.defaults['tab-size'] = 4; + SyntaxHighlighter.defaults['gutter'] = false; + SyntaxHighlighter.defaults['toolbar'] = false; + SyntaxHighlighter.all() +</script> + +<!-- JQuery --> + +<script type="text/javascript" src="js/jquery-1.6.4.min.js"></script> + +<!-- Image Scaler --> + +<script type="text/javascript" src="js/imagescaler.js"></script> + +<!-- Table Styler --> + +<script type="text/javascript" src="js/tablestyler.js"></script> + +<!-- Apache Polygene WebSite Progressive Enhancement --> + +<link href="css/progressive-enhancement.css" rel="stylesheet" type="text/css" /> +<script type="text/javascript" src="js/jquery.scrollTo-1.4.2.js"></script> +<script type="text/javascript" src="js/progressive-enhancement.js"></script> + +<!-- Analytics --> + <script type="text/javascript"> + var _gaq = _gaq || []; + _gaq.push(['_setAccount', 'UA-62007352-1']); + _gaq.push(['_trackPageview']); + + (function() { + var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; + ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; + var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); + })(); + </script> + + </head><body><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="logo"><a href="index.html"><img src="images/logo-standard.png" /></a></div><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="top-nav"><div xmlns="http://www.w3.org/1999/xhtml"; class="toc"><dl><dt><span class="section"><a href="index.html#home">Polygeneâ¢</a></span></dt><dt><span class="section"><a href="intro.html">Introduction</a></span></dt><dt><span class="section"><span xmlns="" href="tutorials.html">Tutorials</span></span></dt><dt><span class="section"><a href="javadocs.html">Javadoc</a></span></dt><dt><span class="section"><a href="samples.html">Samples</a></span></dt><dt><span class="section"><a href="core.html">Core</a></span></dt><dt><span class="section"><a href="libraries.html">Libraries</a></span></dt><dt><span class="section"><a href="extensions.html">Extensions</a></span></dt><dt><span class="section"><a href="tools.html">Tools</a></span></dt><dt><span class="section"><a href="glossary.ht ml">Glossary </a></span></dt></dl></div></div><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="sub-nav"><div xmlns="http://www.w3.org/1999/xhtml"; class="toc"><dl><dt><span class="section"><a href="tutorials.html#_overview">Overview</a></span></dt><dt><span class="section"><a href="two-minutes-intro.html">Polygene⢠in 2 minutes</a></span></dt><dt><span class="section"><a href="ten-minutes-intro.html">Polygene⢠in 10 minutes</a></span></dt><dt><span class="section"><a href="thirty-minutes-intro.html">Polygene⢠in 30 minutes</a></span></dt><dt><span class="section"><a href="howto-depend-on-polygene.html">Depend on Polygeneâ¢</a></span></dt><dt><span class="section"><a href="howto-assemble-application.html">Assemble an Application</a></span></dt><dt><span class="section"><a href="tut-composites.html">Transient Composites Tutorial</a></span></dt><dt><span class="section"><a href="tut-services.html">Services Composites Tutorial</a></span></dt><dt><span class="section"><a href="howto-contextual-fragments.html">Use contextual fragments</a></span></dt><dt><span class="section"><a href="howto-leverage-properties.html">Leverage Properties</a></span></dt><dt><span class="section"><a href="howto-create-constraint.html">Create a Constraint</a></span></dt><dt><span class="section"><a href="howto-create-concern.html">Create a Concern</a></span></dt><dt><span class="section"><a href="howto-create-sideeffect.html">Create a SideEffect</a></span></dt><dt><span class="section"><a href="howto-create-entity.html">Create an Entity</a></span></dt><dt><span class="section"><span xmlns="" href="howto-configure-service.html">Configure a Service</span></span></dt><dt><span class="section"><a href="howto-invocation-annotation.html">Use @Invocation</a></span></dt><dt><span class="section"><a href="build-system.html">Polygene⢠Build System</a></span></dt><dt><span class="section"><a href="community-docs.html">Polygene⢠Documentation</a></span></dt><dt><span class="sectio n"><a href="releasing-apache.html">Releasing Polygeneâ¢</a></span></dt></dl></div></div><div class="section" title="Configure a Service"><div class="titlepage"><div><div><h3 class="title"><a id="howto-configure-service"></a>Configure a Service</h3></div></div></div><p>Polygene⢠supports a Configuration system for services. The configuration instance itself is an Entity and is therefor +readable, writeable and queryable, just like other Entities. This should make Configuration management much simpler, +since you can easily build GUI tools to allow editing of these in runtime. However, to simplify the initial values of +the Configuration instance, Polygene⢠also does the initial bootstrapping of the Configuration entity for you. This HowTo is +going to show how.</p><p>If you want to reproduce whatâs explained in this tutorial, remember to depend on the Core Bootstrap artifact:</p><p>At runtime you will need the Core Runtime artifact too. See the <a class="xref" href="howto-depend-on-polygene.html" title="Depend on Polygeneâ¢">Depend on Polygeneâ¢</a> tutorial for details.</p><div class="section" title="We need a Service"><div class="titlepage"><div><div><h4 class="title"><a id="_we_need_a_service"></a>We need a Service</h4></div></div></div><p>To illustrate these features we create an TravelPlan service, which allows clients to find and make Reservations to +Destinations. For the sake of simplicity, we are leaving out the domain detailsâ¦</p><pre class="programlisting brush: java">public interface TravelPlan +{ + // Domain methods, which are beyond the discussion at hand. +} +</pre><p>So, then there is the ServiceCompositeâ¦</p><pre class="programlisting brush: java">// The package is relevant to the Initial Values discussed later. +package org.apache.polygene.manual.travel; + [...snip...] + +@Mixins( { TravelPlanMixin.class } ) +public interface TravelPlanService extends TravelPlan, ServiceComposite +{} +</pre><p>And then in the Mixin we actually need to connect to a foreign system to obtain the various details that the service +can provide to the clients. For instance, it needs a host name and port and a protocol to use. We put these into a +configuration interface.</p><pre class="programlisting brush: java">public interface TravelPlanConfiguration +{ + Property<String> hostName(); + + @Range( min=0, max=65535 ) + Property<Integer> portNumber(); + + @Matches( "(ssh|rlogin|telnet)" ) + Property<String> protocol(); +} +</pre><p>We used the recommended type-safe Property subtype pattern, and for each PortNumber and Protocol we have defined a +Constraint required.</p><p>Now we can access this configuration in the TravelPlanMixin like this;</p><pre class="programlisting brush: java">import org.apache.polygene.api.configuration.Configuration; + +public class TravelPlanMixin implements TravelPlan +{ + @This + Configuration<TravelPlanConfiguration> config; + + private void foo() + { + TravelPlanConfiguration tpConf = config.get(); + String hostName = tpConf.hostName().get(); + // ... + } + [...snip...] + +} +</pre><p>And from the Service point of view, it doesnât need to worry about where the configuration really comes from. But it may +want to control when the Configuration should be refreshed, to ensure that atomic changes are happening. This is done +with the refresh() method in the Configuration interface;</p><pre class="programlisting brush: java">public void doSomething() +{ + // Refresh Configuration before reading it. + config.refresh(); + + TravelPlanConfiguration tpConf = config.get(); + // ... +} +</pre><p>This ensures that any updates to the Configuration that has occurred will be retrieved and available to the Service. +Since Configuration instance is an Entity, the UnitOfWork system will ensure that the Configuration is consistent and +not in the middle of value changes.</p><div class="section" title="Initial Values"><div class="titlepage"><div><div><h5 class="title"><a id="_initial_values"></a>Initial Values</h5></div></div></div><p>The initial Configuration instance will be created automatically behind the scenes, by reading a properties file and +create an Entity with the same identity as the identity of the service. That was a handful. Services are, as we know, +singletons and have an identity specified at assembly. Even if it is not provided, one will automatically be assigned. +The serviceâs "identifiedBy" will be used as the identifier for the Configuration entity and stored in the visible +EntityStore. This identity is also used to locate a properties file in the same package as the ServiceComposite belongs +to.</p><p>So, we create a properties file, where the keys are the names of the properties in TravelPlanConfiguration.</p><pre class="programlisting brush: bash"># Hostname to the TravelPlan service +hostName=niclas.hedhman.org + +# Port number to use for the connection +portNumber=5439 + +# Protocol to use; Valid options "ssh", "rlogin", "telnet" +protocol=ssh + +</pre><p>File: org/hedhman/niclas/travel/TravelPlanService.properties</p><p>Note that the file resides in the directory equivalent to the package name of the TravelPlanService.</p><p>And this would work with the standard assembly.</p><pre class="programlisting brush: java">public void assemble(ModuleAssembly module) throws AssemblyException +{ + module.addServices(TravelPlanService.class).instantiateOnStartup(); +} +</pre></div></div><div class="section" title="Non-default Identity"><div class="titlepage"><div><div><h4 class="title"><a id="_non_default_identity"></a>Non-default Identity</h4></div></div></div><p>If you need to use multiple instances of the same service, or that the service has a non-default Identity, then you need +to name the properties file according to the Identity of the service declaration, but the file will still need to be in +the same package as the ServiceComposite sub type, the TravelPlanService in the above example. For instance;</p><pre class="programlisting brush: java">public void assemble(ModuleAssembly module) throws AssemblyException +{ + module.addServices(TravelPlanService.class) + .instantiateOnStartup() + .identifiedBy("ExpediaService"); + + module.addServices(TravelPlanService.class) + .instantiateOnStartup() + .identifiedBy("OrbitzService"); +} +</pre><p>And the two files for configuration,</p><pre class="programlisting brush: bash"># Hostname to the TravelPlan service +hostName=expedia.hedhman.org + +# Port number to use for the connection +portNumber=9251 + +# Protocol to use; Valid options "ssh", "rlogin", "telnet" +protocol=ssh +</pre><p>File: org/apache/polygene/manual/travel/ExpediaService.properties</p><pre class="programlisting brush: bash"># Hostname to the TravelPlan service +hostName=orbitz.hedhman.org + +# Port number to use for the connection +portNumber=7412 + +# Protocol to use; Valid options "ssh", "rlogin", "telnet" +protocol=rlogin +</pre><p>File: org/apache/polygene/manual/travel/OrbitzService.properties</p></div><div class="section" title="Changing Configuration in runtime"><div class="titlepage"><div><div><h4 class="title"><a id="_changing_configuration_in_runtime"></a>Changing Configuration in runtime</h4></div></div></div><p>Unlike most frameworks, the Configuration in Polygene⢠is an active Entity, and once the properties file has been read once +at the first(!) startup, it no longer serves any purpose. The Configuration will always be retrieved from the +EntityStore. Changes to the properties file are not taken into consideration if the Configuration entity is found in the +entity store.</p><p>But that also means that applications should not cache the configuration values, and instead read them from the +Configuration instance every time needed, and do a refresh() method call when it is safe to update the Configuration +Entity with new values.</p></div></div><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="footer"><p> + Copyright © 2015 The Apache Software Foundation, Licensed under the <a href="http://www.apache.org/licenses/"; target="_blank">Apache License, Version 2.0</a>. + <br /><small> + Apache Polygene, Polygene, Apache, the Apache feather logo, and the Apache Polygene project logo are trademarks of The Apache Software Foundation.<br /> + All other marks mentioned may be trademarks or registered trademarks of their respective owners. + </small></p></div></body></html> \ No newline at end of file http://git-wip-us.apache.org/repos/asf/polygene-website/blob/ba3a0fac/content/java/develop/howto-contextual-fragments.html ---------------------------------------------------------------------- diff --git a/content/java/develop/howto-contextual-fragments.html b/content/java/develop/howto-contextual-fragments.html new file mode 100644 index 0000000..1e1e10c --- /dev/null +++ b/content/java/develop/howto-contextual-fragments.html @@ -0,0 +1,93 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Use contextual fragments</title><link rel="stylesheet" type="text/css" href="css/style.css" /><meta name="generator" content="DocBook XSL Stylesheets V1.76.1" /><link rel="home" href="index.html" title="" /><link rel="up" href="tutorials.html" title="Tutorials" /><link rel="prev" href="tut-services.html" title="Services Composites Tutorial" /><link rel="next" href="howto-leverage-properties.html" title="Leverage Properties" /> + + +<!-- favicon --> + +<link rel="shortcut icon" href="http://polygene.apache.org/favicon.ico"; type="image/vnd.microsoft.icon" /> +<link rel="icon" href="http://polygene.apache.org/favicon.ico"; type="image/x-icon" /> + +<!-- style --> + +<link href="css/shCore.css" rel="stylesheet" type="text/css" /> +<link href="css/shCoreEclipse.css" rel="stylesheet" type="text/css" /> +<link href="css/shThemeEclipse.css" rel="stylesheet" type="text/css" /> +<link href="css/polygene.css" rel="stylesheet" type="text/css" /> + +<!-- Syntax Highlighter --> + +<script type="text/javascript" src="js/shCore.js"></script> +<script type="text/javascript" src="js/shBrushJava.js"></script> +<script type="text/javascript" src="js/shBrushScala.js"></script> +<script type="text/javascript" src="js/shBrushJScript.js"></script> +<script type="text/javascript" src="js/shBrushBash.js"></script> +<script type="text/javascript" src="js/shBrushPlain.js"></script> +<script type="text/javascript" src="js/shBrushXml.js"></script> +<script type="text/javascript" src="js/shBrushGroovy.js"></script> +<script type="text/javascript" src="js/shBrushPython.js"></script> +<script type="text/javascript" src="js/shBrushRuby.js"></script> +<script type="text/javascript" src="js/shBrushCSharp.js"></script> + +<script type="text/javascript"> + SyntaxHighlighter.defaults['tab-size'] = 4; + SyntaxHighlighter.defaults['gutter'] = false; + SyntaxHighlighter.defaults['toolbar'] = false; + SyntaxHighlighter.all() +</script> + +<!-- JQuery --> + +<script type="text/javascript" src="js/jquery-1.6.4.min.js"></script> + +<!-- Image Scaler --> + +<script type="text/javascript" src="js/imagescaler.js"></script> + +<!-- Table Styler --> + +<script type="text/javascript" src="js/tablestyler.js"></script> + +<!-- Apache Polygene WebSite Progressive Enhancement --> + +<link href="css/progressive-enhancement.css" rel="stylesheet" type="text/css" /> +<script type="text/javascript" src="js/jquery.scrollTo-1.4.2.js"></script> +<script type="text/javascript" src="js/progressive-enhancement.js"></script> + +<!-- Analytics --> + <script type="text/javascript"> + var _gaq = _gaq || []; + _gaq.push(['_setAccount', 'UA-62007352-1']); + _gaq.push(['_trackPageview']); + + (function() { + var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; + ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; + var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); + })(); + </script> + + </head><body><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="logo"><a href="index.html"><img src="images/logo-standard.png" /></a></div><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="top-nav"><div xmlns="http://www.w3.org/1999/xhtml"; class="toc"><dl><dt><span class="section"><a href="index.html#home">Polygeneâ¢</a></span></dt><dt><span class="section"><a href="intro.html">Introduction</a></span></dt><dt><span class="section"><span xmlns="" href="tutorials.html">Tutorials</span></span></dt><dt><span class="section"><a href="javadocs.html">Javadoc</a></span></dt><dt><span class="section"><a href="samples.html">Samples</a></span></dt><dt><span class="section"><a href="core.html">Core</a></span></dt><dt><span class="section"><a href="libraries.html">Libraries</a></span></dt><dt><span class="section"><a href="extensions.html">Extensions</a></span></dt><dt><span class="section"><a href="tools.html">Tools</a></span></dt><dt><span class="section"><a href="glossary.ht ml">Glossary </a></span></dt></dl></div></div><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="sub-nav"><div xmlns="http://www.w3.org/1999/xhtml"; class="toc"><dl><dt><span class="section"><a href="tutorials.html#_overview">Overview</a></span></dt><dt><span class="section"><a href="two-minutes-intro.html">Polygene⢠in 2 minutes</a></span></dt><dt><span class="section"><a href="ten-minutes-intro.html">Polygene⢠in 10 minutes</a></span></dt><dt><span class="section"><a href="thirty-minutes-intro.html">Polygene⢠in 30 minutes</a></span></dt><dt><span class="section"><a href="howto-depend-on-polygene.html">Depend on Polygeneâ¢</a></span></dt><dt><span class="section"><a href="howto-assemble-application.html">Assemble an Application</a></span></dt><dt><span class="section"><a href="tut-composites.html">Transient Composites Tutorial</a></span></dt><dt><span class="section"><a href="tut-services.html">Services Composites Tutorial</a></span></dt><dt><span class="section"><sp an xmlns="" href="howto-contextual-fragments.html">Use contextual fragments</span></span></dt><dt><span class="section"><a href="howto-leverage-properties.html">Leverage Properties</a></span></dt><dt><span class="section"><a href="howto-create-constraint.html">Create a Constraint</a></span></dt><dt><span class="section"><a href="howto-create-concern.html">Create a Concern</a></span></dt><dt><span class="section"><a href="howto-create-sideeffect.html">Create a SideEffect</a></span></dt><dt><span class="section"><a href="howto-create-entity.html">Create an Entity</a></span></dt><dt><span class="section"><a href="howto-configure-service.html">Configure a Service</a></span></dt><dt><span class="section"><a href="howto-invocation-annotation.html">Use @Invocation</a></span></dt><dt><span class="section"><a href="build-system.html">Polygene⢠Build System</a></span></dt><dt><span class="section"><a href="community-docs.html">Polygene⢠Documentation</a></span></dt><dt><span class="sectio n"><a href="releasing-apache.html">Releasing Polygeneâ¢</a></span></dt></dl></div></div><div class="section" title="Use contextual fragments"><div class="titlepage"><div><div><h3 class="title"><a id="howto-contextual-fragments"></a>Use contextual fragments</h3></div></div></div><p>Contextual fragments are fragments that are added to the composites during assembly time. That means that they are not +present in the composite declarations, but a start-up decision what should be added. Once the application instance is +created, it is no longer possible to modify which fragments are attached.</p><p>Typical use-case is tracing and debugging. Other potential uses are additional security or context interfaces needing +access to internal mixins not originally intended for, such as GUI frameworks doing reflection on certain composites. +We strongly recommend against using this feature, as it is not needed as commonly as you may think.</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>Constraints are not supported to be contextual at the moment.</p></div><p>If you want to reproduce whatâs explained in this tutorial, remember to depend on the Core Bootstrap artifact:</p><p>At runtime you will need the Core Runtime artifact too. See the <a class="xref" href="howto-depend-on-polygene.html" title="Depend on Polygeneâ¢">Depend on Polygeneâ¢</a> tutorial for details.</p><p>The mixins, sideeffects and concerns are added during the bootstrap phase. It is very straight-forward;</p><pre class="programlisting brush: java">public class TraceAll +{ + public void assemble( ModuleAssembly module ) + throws AssemblyException + { + ServiceDeclaration decl = module.addServices( PinSearchService.class ); + if( Boolean.getBoolean( "trace.all" ) ) + { + decl.withConcerns( TraceAllConcern.class ); + } + } +} + +</pre><p>In the example above, we add the TraceAllConcern from the Logging Library if the system property "trace.all" is true. +If the system property is not set to true, there will be no TraceAllConcern on the PinSearchService.</p><p>Concerns that are added in this way will be at the top of the method invocation stack, i.e. will be the first one to be +called and last one to be completed.</p><p>SideEffects that are added in this way will be the last oneâs to be executed.</p></div><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="footer"><p> + Copyright © 2015 The Apache Software Foundation, Licensed under the <a href="http://www.apache.org/licenses/"; target="_blank">Apache License, Version 2.0</a>. + <br /><small> + Apache Polygene, Polygene, Apache, the Apache feather logo, and the Apache Polygene project logo are trademarks of The Apache Software Foundation.<br /> + All other marks mentioned may be trademarks or registered trademarks of their respective owners. + </small></p></div></body></html> \ No newline at end of file http://git-wip-us.apache.org/repos/asf/polygene-website/blob/ba3a0fac/content/java/develop/howto-create-concern.html ---------------------------------------------------------------------- diff --git a/content/java/develop/howto-create-concern.html b/content/java/develop/howto-create-concern.html new file mode 100644 index 0000000..8b97878 --- /dev/null +++ b/content/java/develop/howto-create-concern.html @@ -0,0 +1,163 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Create a Concern</title><link rel="stylesheet" type="text/css" href="css/style.css" /><meta name="generator" content="DocBook XSL Stylesheets V1.76.1" /><link rel="home" href="index.html" title="" /><link rel="up" href="tutorials.html" title="Tutorials" /><link rel="prev" href="howto-create-constraint.html" title="Create a Constraint" /><link rel="next" href="howto-create-sideeffect.html" title="Create a SideEffect" /> + + +<!-- favicon --> + +<link rel="shortcut icon" href="http://polygene.apache.org/favicon.ico"; type="image/vnd.microsoft.icon" /> +<link rel="icon" href="http://polygene.apache.org/favicon.ico"; type="image/x-icon" /> + +<!-- style --> + +<link href="css/shCore.css" rel="stylesheet" type="text/css" /> +<link href="css/shCoreEclipse.css" rel="stylesheet" type="text/css" /> +<link href="css/shThemeEclipse.css" rel="stylesheet" type="text/css" /> +<link href="css/polygene.css" rel="stylesheet" type="text/css" /> + +<!-- Syntax Highlighter --> + +<script type="text/javascript" src="js/shCore.js"></script> +<script type="text/javascript" src="js/shBrushJava.js"></script> +<script type="text/javascript" src="js/shBrushScala.js"></script> +<script type="text/javascript" src="js/shBrushJScript.js"></script> +<script type="text/javascript" src="js/shBrushBash.js"></script> +<script type="text/javascript" src="js/shBrushPlain.js"></script> +<script type="text/javascript" src="js/shBrushXml.js"></script> +<script type="text/javascript" src="js/shBrushGroovy.js"></script> +<script type="text/javascript" src="js/shBrushPython.js"></script> +<script type="text/javascript" src="js/shBrushRuby.js"></script> +<script type="text/javascript" src="js/shBrushCSharp.js"></script> + +<script type="text/javascript"> + SyntaxHighlighter.defaults['tab-size'] = 4; + SyntaxHighlighter.defaults['gutter'] = false; + SyntaxHighlighter.defaults['toolbar'] = false; + SyntaxHighlighter.all() +</script> + +<!-- JQuery --> + +<script type="text/javascript" src="js/jquery-1.6.4.min.js"></script> + +<!-- Image Scaler --> + +<script type="text/javascript" src="js/imagescaler.js"></script> + +<!-- Table Styler --> + +<script type="text/javascript" src="js/tablestyler.js"></script> + +<!-- Apache Polygene WebSite Progressive Enhancement --> + +<link href="css/progressive-enhancement.css" rel="stylesheet" type="text/css" /> +<script type="text/javascript" src="js/jquery.scrollTo-1.4.2.js"></script> +<script type="text/javascript" src="js/progressive-enhancement.js"></script> + +<!-- Analytics --> + <script type="text/javascript"> + var _gaq = _gaq || []; + _gaq.push(['_setAccount', 'UA-62007352-1']); + _gaq.push(['_trackPageview']); + + (function() { + var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; + ga.src = ('https:' == document.location.protocol ? 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See the <a class="xref" href="howto-depend-on-polygene.html" title="Depend on Polygeneâ¢">Depend on Polygeneâ¢</a> tutorial for details.</p><div class="section" title="Typed Concern"><div class="titlepage"><div><div><h4 class="title"><a id="_typed_concern"></a>Typed Concern</h4></div></div></div><p>A typed Concern is a Java class that implements the MixinType it can be used on:</p><pre class="programlisting brush: java">public class InventoryConcern extends Conce rnOf<Order> + implements Order +{ + @Service + private InventoryService inventory; + + @Override + public void addLineItem( LineItem item ) + { + String productCode = item.productCode().get(); + int quantity = item.quantity().get(); + inventory.remove( productCode, quantity ); + next.addLineItem( item ); + } + + @Override + public void removeLineItem( LineItem item ) + { + String productCode = item.productCode().get(); + int quantity = item.quantity().get(); + inventory.add( productCode, quantity ); + next.removeLineItem( item ); + } +} +</pre><p>Note that we could have implemented the InventoryConcern as an abstract class if we were not interested in <span class="emphasis"><em>all</em></span> the methods in the Order interface. +Extending the ConcernOf is a convenience mechanism, instead of an explicit @ConcernFor annotation on +a private field, which can be used in rare occasions when you are not able to extend. This base class defines the next +field, which is set up by the Polygene⢠runtime and points to the next fragment in the call stack. We can also see that the +InventoryService is provided to the concern, which is done with dependency injection. Polygene⢠also supports dependency +injection via constructors and methods.</p><p>It can be used as follows;</p><pre class="programlisting brush: java">@Concerns( InventoryConcern.class ) +public interface Order +{ + void addLineItem( LineItem item ); + void removeLineItem( LineItem item ); + + [...snip...] + +</pre><p>Methods of the Concern Fragment will be called before the Mixin invocation.</p></div><div class="section" title="Generic Concern"><div class="titlepage"><div><div><h4 class="title"><a id="_generic_concern"></a>Generic Concern</h4></div></div></div><p>A generic Concern is a Java class that implements java.lang.reflect.InvocationHandler which allows it to be used on any +arbitrary MixinType.</p><pre class="programlisting brush: java">public class MyGenericConcern extends GenericConcern +{ + @Override + public Object invoke( Object proxy, Method method, Object[] args ) + throws Throwable + { + // Do whatever you want + + [...snip...] + +</pre><p>It can be used as follows;</p><pre class="programlisting brush: java">@Concerns( MyGenericConcern.class ) +public interface AnyMixinType +{ + + [...snip...] + + @MyAnnotation + void doSomething(); + + void doSomethingElse(); + +</pre><p>Methods of the Concern Fragment will be called before the Mixin invocation.</p><div class="section" title="AppliesTo"><div class="titlepage"><div><div><h5 class="title"><a id="_appliesto"></a>AppliesTo</h5></div></div></div><p>For generic Concerns that should only trigger on methods with specific annotations or fulfilling some expression, add +@AppliesTo annotation to the Concern class which points to either triggering annotation(s), or to AppliesToFilter +implementation(s).</p><p>The Concern is invoked if one of the triggering annotations is found or one of the AppliesToFilter accepts the +invocation. In other words the AppliesTo arguments are ORâed.</p><p>Here is how the declaration goes ;</p><pre class="programlisting brush: java">@AppliesTo( { MyAnnotation.class, MyAppliesToFilter.class } ) +public class MyGenericConcern extends GenericConcern +{ +</pre><p>And how to use the annotation ;</p><pre class="programlisting brush: java">@Concerns( MyGenericConcern.class ) +public interface AnyMixinType +{ + + @MyAnnotation + void doSomething(); + + void doSomethingElse(); + +} +</pre><p>Here only the doSomething() method will see the Concern applied whereas the doSomethingElse() method wonât.</p><p>Finally here is how to implement an AppliesToFilter:</p><pre class="programlisting brush: java">public class MyAppliesToFilter implements AppliesToFilter +{ + public boolean appliesTo( Method method, Class<?> mixin, Class<?> compositeType, Class<?> modifierClass ) + { + boolean appliesTo = evaluate(method); // Do whatever you want + return appliesTo; + } + + [...snip...] + + private boolean evaluate( Method method ) + { + return true; + } +</pre></div></div></div><div xmlns="" xmlns:exsl="http://exslt.org/common"; class="footer"><p> + Copyright © 2015 The Apache Software Foundation, Licensed under the <a href="http://www.apache.org/licenses/"; target="_blank">Apache License, Version 2.0</a>. + <br /><small> + Apache Polygene, Polygene, Apache, the Apache feather logo, and the Apache Polygene project logo are trademarks of The Apache Software Foundation.<br /> + All other marks mentioned may be trademarks or registered trademarks of their respective owners. + </small></p></div></body></html> \ No newline at end of file
