Author: cbrisson
Date: Tue Jul 26 16:21:03 2016
New Revision: 1754153
URL: http://svn.apache.org/viewvc?rev=1754153&view=rev
Log:
[site] review configuration and dev guide pages, document new conversion
handler feature
Modified:
velocity/site/cms/trunk/content/engine/devel/configuration.mdtext
velocity/site/cms/trunk/content/engine/devel/developer-guide.mdtext
velocity/site/cms/trunk/content/engine/devel/left.nav
velocity/site/cms/trunk/content/engine/devel/upgrading.mdtext
velocity/site/cms/trunk/content/engine/devel/user-guide.mdtext
velocity/site/cms/trunk/content/engine/index.mdtext
Modified: velocity/site/cms/trunk/content/engine/devel/configuration.mdtext
URL:
http://svn.apache.org/viewvc/velocity/site/cms/trunk/content/engine/devel/configuration.mdtext?rev=1754153&r1=1754152&r2=1754153&view=diff
==============================================================================
--- velocity/site/cms/trunk/content/engine/devel/configuration.mdtext (original)
+++ velocity/site/cms/trunk/content/engine/devel/configuration.mdtext Tue Jul
26 16:21:03 2016
@@ -18,21 +18,21 @@ Below are listed the configuration keys
## Logging
-`runtime.log.instance = *Java Object instance*`
+**`runtime.log.instance`** = *Java Object instance*
> Living Java instance, that must implement the interface org.slf4j.Logger.
> This property can only be set programmatically. By default, Velocity uses
> the SLF4J static discovery mechanism, see the
> [Logging](developer-guide.html#logging) section in the dev guide.
-`runtime.log.name = Velocity`
+**`runtime.log.name = Velocity`**
> If no living Logger instance has been given using the previous property,
> Velocity will get a Logger object using the provided name.
-`runtime.log.invalid.references = true`
+**`runtime.log.invalid.references = true`**
> Property to turn off the log output when a reference isn't valid. Good thing
> to turn off in production, but very valuable for debugging.
## Character Encoding
-`input.encoding = UTF-8`
+**`input.encoding = UTF-8`**
> Character encoding for input (templates). If not specified, Velocity relies
> on the 'file.encoding' system property.
@@ -40,92 +40,98 @@ Below are listed the configuration keys
### #define() Directive
-`define.provide.scope.control = false`
+**`define.provide.scope.control = false`**
> Used to turn on the automatic provision of the $define scope control during
> #define() calls. The default is false. Set it to true if you want a local,
> managed namespace you can put references in when within a #define block or
> if you want it for more advanced #break usage.
### #evaluate() Directive
-`evaluate.provide.scope.control = false`
+**`evaluate.provide.scope.control = false`**
> Used to turn on the automatic provision of the $evaluate scope during
> #evaluate() or Velocity[Engine].evaluate(...) calls. The default is false.
> Set it to true if you want a local, managed namespace you can put references
> in during an evaluation or if you want it for more advanced #break usage.
### #foreach() Directive
-`foreach.provide.scope.control = true`
+**`foreach.provide.scope.control = true`**
> Used to control the automatic provision of the $foreach scope during
> #foreach calls. This gives access to the foreach status information (e.g.
> $foreach.index or $foreach.hasNext). The default is true. Set it to false if
> unused and you want a tiny performance boost.
-`directive.foreach.maxloops = -1`
+**`directive.foreach.maxloops = -1`**
> Maximum allowed number of loops for a #foreach() statement.
-`directive.foreach.skip.invalid = true`
+**`directive.foreach.skip.invalid = true`**
> Tells #foreach to simply skip rendering when the object it is iterating over
> is not or cannot produce a valid Iterator.
### #if() Directive
-`directive.if.tostring.nullcheck = true`
+**`directive.if.tostring.nullcheck = true`**
> Default behavior is to check return value of toString() and treat an object
> with toString() that returns null as null. If all objects have toString()
> methods that never return null, this check is unnecessary and can be
> disabled to gain performance. In Velocity 1.5, no such null check was
> performed.
### #set() Directive
-`directive.set.null.allowed = false`
+**`directive.set.null.allowed = false`**
> If true, having a right hand side of a #set() statement with an invalid
> reference or null value will set the left hand side to null. If false, the
> left hand side will stay the same.
### #include() and #parse() Directives
-`directive.include.output.errormsg.start = <!-- include error :`
-`directive.include.output.errormsg.end = see error log --> `
+**`directive.include.output.errormsg.start = <!-- include error :`**
+**`directive.include.output.errormsg.end = see error log --> `**
> Defines the beginning and ending tags for an in-stream error message in the
> case of a problem with the #include() directive. If both the .start and .end
> tags are defined, an error message will be output to the stream, of the form
> '.start msg .end' where .start and .end refer to the property values. Output
> to the render stream will only occur if both the .start and .end (next) tag
> are defined.
-`directive.parse.max.depth = 10`
+**`directive.parse.max.depth = 10`**
> Defines the allowable parse depth for a template. A template may #parse()
> another template which itself may have a #parse() directive. This value
> prevents runaway #parse() recursion.
-`template.provide.scope.control = false`
+**`template.provide.scope.control = false`**
> Used to turn on the automatic provision of the $template scope control
> during #parse calls and template.merge(...) calls. The default is false. Set
> it to true if you want a secure namespace for your template variables or
> more advanced #break control.
## Resource Management
-`resource.manager.logwhenfound = true`
+**`resource.manager.class =
org.apache.velocity.runtime.resource.ResourceManagerImpl`**
+
+> Replace the Velocity default Resource Manager class. A resource manager
implementation must implement the
(`org.apache.velocity.runtime.resource.ResourceManager`)[apidocs/org/apache/velocity/runtime/resource/ResourceManager.html]
interface. A description of the requirements of a resource manager is out of
scope for this document. Implementors are encouraged to review the default
implementation.
+
+The following resource management configuration keys only apply to the default
Resource Manager.
+
+**`resource.manager.logwhenfound = true`**
> Switch to control logging of 'found' messages from resource manager. When a
> resource is found for the first time, the resource name and classname of the
> loader that found it will be noted in the runtime log.
-`resource.manager.cache.class`
+**`resource.manager.cache.class =
org.apache.velocity.runtime.resource.ResourceCacheImpl`**
-> Declares the class to be used for resource caching. The current default is
`org.apache.velocity.runtime.resource.ResourceCacheImpl`. When
`resource.manager.defaultcache.size` is set to 0, then the default
implementation is the standard Java `ConcurrentHashMap`. Otherwise, a non-zero
cache size uses an LRU Map. The default cache size is 89. Note that the
ConcurrentHashMap may be better at thread concurrency.
+> Replace the Velocity default Resource Cache class. A resource cache
implementation must implement the
(`org.apache.velocity.runtime.resource.ResourceCache`)[apidocs/org/apache/velocity/runtime/resource/ResourceCache.html]
interface As with the resource manager. A description of the requirements of a
resource manager is out of scope for this document. Implementors are
encouraged to review the default implementation.
-`resource.manager.defaultcache.size`
+**`resource.manager.defaultcache.size = 89`**
-> Sets the size of the default implementation of the resource manager cache
size. The default is 89.
+> Sets the size of the default implementation of the resource manager cache
size. When `resource.manager.defaultcache.size` is set to 0, then the default
implementation uses the standard Java `ConcurrentHashMap`. Otherwise, a
non-zero cache size uses an LRU Map. The default cache size is 89. Note that
the ConcurrentHashMap may be better at thread concurrency.
-`resource.loader = <name> (default = file)`
+**`resource.loader = file`**
> *Multi-valued key. Will accept CSV for value.* Public name of a resource
> loader to be used. This public name will then be used in the specification
> of the specific properties for that resource loader. Note that as a
> multi-valued key, it's possible to pass a value like "file, class" (sans
> quotes), indicating that following will be configuration values for two
> loaders.
-`<name>.loader.description = Velocity File Resource Loader`
+** *name*`.loader.description = Velocity File Resource Loader`**
> Description string for the given loader.
-`<name>.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader`
+** *name*`.resource.loader.class =
org.apache.velocity.runtime.resource.loader.FileResourceLoader`**
> Name of implementation class for the loader. The default loader is the file
> loader.
-`<name>.resource.loader.path = .`
+** *name*`.resource.loader.path = .`**
-> *Multi-valued key. Will accept CSV for value.* Root(s) from which the
loader loads templates. Templates may live in subdirectories of this root. ex.
homesite/index.vm This configuration key applies currently to the
FileResourceLoader and JarResourceLoader.
+> *Multi-valued key. Will accept CSV for value.* Root(s) from which the loader
loads templates. Templates may live in subdirectories of this root. ex.
homesite/index.vm This configuration key applies currently to the
FileResourceLoader and JarResourceLoader.
-`<name>.resource.loader.cache = false`
+** *name*`.resource.loader.cache = false`**
> Controls caching of the templates in the loader. Default is false, to make
> life easy for development and debugging. This should be set to true for
> production deployment. When 'true', the `modificationCheckInterval`
> property applies. This allows for the efficiency of caching, with the
> convenience of controlled reloads - useful in a hosted or ISP environment
> where templates can be modifed frequently and bouncing the application or
> servlet engine is not desired or permitted.
-`<name>.resource.loader.modificationCheckInterval = 2`
+** *name*`.resource.loader.modificationCheckInterval = 2`**
> This is the number of seconds between modification checks when caching is
> turned on. When this is an integer > 0, this represents the number of
> seconds between checks to see if the template was modified. If the template
> has been modified since last check, then it is reloaded and reparsed.
> Otherwise nothing is done. When <= 0, no modification checks will take
> place, and assuming that the property `cache` (above) is true, once a
> template is loaded and parsed the first time it is used, it will not be
> checked or reloaded after that until the application or servlet engine is
> restarted.
@@ -141,75 +147,76 @@ Below are listed the configuration keys
## Velocimacros
-`velocimacro.library = VM_global_library.vm `
+**`velocimacro.library = VM_global_library.vm `**
> *Multi-valued key. Will accept CSV for value.* Filename(s) of Velocimacro
> library to be loaded when the Velocity Runtime engine starts. These
> Velocimacros are accessable to all templates. The file is assumed to be
> relative to the root of the file loader resource path.
-`velocimacro.permissions.allow.inline = true`
+**`velocimacro.permissions.allow.inline = true`**
> Determines of the definition of new Velocimacros via the #macro() directive
> in templates is allowed. The default value is true, meaning any template
> can define and use new Velocimacros. Note that depending on other
> properties, those #macro() statements can replace global definitions.
-`velocimacro.permissions.allow.inline.to.replace.global = false `
+**`velocimacro.permissions.allow.inline.to.replace.global = false`**
> Controls if a Velocimacro defind 'inline' in a template can replace a
> Velocimacro defined in a library loaded at startup.
-`velocimacro.permissions.allow.inline.local.scope = false`
+**`velocimacro.permissions.allow.inline.local.scope = false`**
> Controls 'private' templates namespaces for Velocimacros. When true, a
> #macro() directive in a template creates a Velocimacro that is accessable
> only from the defining template. This means that Velocimacros cannot be
> shared unless they are in the global or local library loaded at startup.
> (See above.) It also means that templates cannot interfere with each other.
> This property also allows a technique where there is a 'default'
> Velocimacro definition in the global or local library, and a template can
> 'override' the implementation for use within that template. This occurrs
> because when this property is true, the template's namespace is searched for
> a Velocimacro before the global namespace, therefore allowing the override
> mechanism.
-`velocimacro.context.localscope = false`
+**`velocimacro.context.localscope = false`**
> Controls whether reference access (set/get) within a Velocimacro will change
> the context, or be of local scope in that Velocimacro. This feature is
> deprecated and has been removed in Velocity 2.0. Instead, please use the
> $macro namespace for storage of references local to your Velocimacro. (e.g.
> #set( $macro.foo = 'bar') and $macro.foo)
-`velocimacro.library.autoreload = false`
+**`velocimacro.library.autoreload = false`**
> Controls Velocimacro library autoloading. When set to `true` the source
> Velocimacro library for an invoked Velocimacro will be checked for changes,
> and reloaded if necessary. This allows you to change and test Velocimacro
> libraries without having to restart your application or servlet container,
> just like you can with regular templates. This mode only works when caching
> is *off* in the resource loaders (e.g. `file.resource.loader.cache = false`
> ). This feature is intended for development, not for production.
-`velocimacro.arguments.strict = false`
+**`velocimacro.arguments.strict = false`**
> When set to true, will throw a `ParseErrorException` when parsing a template
> containing a macro with an invalid number of arguments. Is set to false by
> default to maintain backwards compatibility with templates written before
> this feature became available.
-`velocimacro.body.reference = false`
+**`velocimacro.body.reference = false`**
> Defines name of the reference that can be used to get the body content (an
> AST block) given for a block macro call (e.g. #@myMacro() has a body #end).
> The default reference name is "bodyContent" (e.g. $bodyContent). This block
> macro feature was introduced in Velocity 1.7.
-`macro.provide.scope.control = false`
+**`macro.provide.scope.control = false`**
> Used to turn on the automatic provision of the $macro scope control during
> #macro calls. The default is false. Set it to true if you need a local
> namespace in macros or more advanced #break controls.
-`<somebodymacro>.provide.scope.control = false`
+**`<somebodymacro>.provide.scope.control = false`**
> Used to turn on the automatic provision of the $<nameofthemacro> scope
> control during a call to a macro with a body (e.g. #@foo #set($foo.a=$b) ...
> $foo.a #end). The default is false. Set it to true if you happen to need a
> namespace just for your macro's body content or more advanced #break
> controls.
-</p>
## Strict Reference Setting
-`runtime.references.strict = false`
+**`runtime.references.strict = false`**
-> New in Velocity 1.6, when set to true Velocity will throw a
`MethodInvocationException` for references that are not defined in the context,
or have not been defined with a #set directive. This setting will also throw
an exception if an attempt is made to call a non-existing property on an object
or if the object is null. When this property is true then property
'directive.set.null.allowed' is also set to true. Also,
'directive.foreach.skip.invalid' defaults to true when this property is true,
but explicitly setting 'directive.foreach.skip.invalid' will override this
default. For a complete discussion see <a
href="user-guide.html#strict-reference-mode">Strict References Setting</a>.
->
-> `runtime.references.strict.escape = false` Changes escape behavior such that
putting a forward slash before a reference or macro always escapes the
reference or macro and absorbs the forward slash regardless if the reference or
macro is defined. For example "\$foo" always renders as "$foo", or "\#foo()" is
always rendered as "#foo()". This escape behavior is of use in strict mode
since unintended strings of characters that look like references or macros will
throw an exception. This provides an easy way to escape these references.
However, even in non-strict mode the developer may find this a more consistent
and reliable method for escaping.
+> When set to true Velocity will throw a `MethodInvocationException` for
references that are not defined in the context, or have not been defined with a
#set directive. This setting will also throw an exception if an attempt is
made to call a non-existing property on an object or if the object is null.
When this property is true then property `directive.set.null.allowed` is also
set to true. Also, `directive.foreach.skip.invalid` defaults to true when this
property is true, but explicitly setting `directive.foreach.skip.invalid` will
override this default. For a complete discussion see [Strict References
Setting](user-guide.html#strict-reference-mode).
+
+**`runtime.references.strict.escape = false`**
+
+> Changes escape behavior such that putting a forward slash before a reference
or macro always escapes the reference or macro and absorbs the forward slash
regardless if the reference or macro is defined. For example "\$foo" always
renders as "$foo", or "\#foo()" is always rendered as "#foo()". This escape
behavior is of use in strict mode since unintended strings of characters that
look like references or macros will throw an exception. This provides an easy
way to escape these references. However, even in non-strict mode the developer
may find this a more consistent and reliable method for escaping.
## String Interpolation
-`runtime.interpolate.string.literals = true`
+**`runtime.interpolate.string.literals = true`**
> Controls interpolation mechanism of VTL String Literals. Note that a VTL
> StringLiteral is specifically a string using double quotes that is used in a
> #set() statement, a method call of a reference, a parameter to a VM, or as
> an argument to a VTL directive in general. See the VTL reference for
> further information.
## Math
-`runtime.strict.math = false`
+**`runtime.strict.math = false`**
> Affects all math operations in VTL. If changed to true, this will cause
> Velocity to throw a MathException whenever one side of a math operation has
> a null value (e.g. `#set( $foo = $null * 5 )`) or when trying to divide by
> zero. If this value is left `false`, then rendering will continue and that
> math operation will be ignored.
## Parser Configuration
-`parser.pool.class = org.apache.velocity.runtime.ParserPoolImpl`
+**`parser.pool.class = org.apache.velocity.runtime.ParserPoolImpl`**
> This property selects the implementation for the parser pool. This class
> must implement ParserPool. Generally there is no reason to change this
> though if you are building a high volume web application you might consider
> including an alternate implementation that automatically adjusts the size of
> the pool.
-`parser.pool.size = 20`
+**`parser.pool.size = 20`**
> This property is used by the default pooling implementation to set the
> number of parser instances that Velocity will create at startup and keep in
> a pool. The default of 20 parsers should be more than enough for most uses.
> In the event that Velocity does run out of parsers, it will indicate so in
> the log, and dynamically create overflow instances as needed. Note that
> these extra parsers will not be added to the pool, and will be discarded
> after use. This will result in very slow operation compared to the normal
> usage of pooled parsers, but this is considered an exceptional condition. A
> web application using Velocity as its view engine might exhibit this
> behavior under extremely high concurrency (such as when getting
> Slashdotted). If you see a corresponding message referencing the
> `parser.pool.size` property in your log files, please increment this
> property immediately to avoid performance degradation.
@@ -217,57 +224,45 @@ Below are listed the configuration keys
See the [Event Handlers](developer-guide.html#event-handlers) section of the
dev guide.
-`eventhandler.include.class = `*classname*
+**`eventhandler.include.class`** = *classname*
> register an [include event
> handler](apidocs/org/apache/velocity/app/event/IncludeEventHandler.html).
-`eventhandler.invalidreference.class = `*classname*
+**`eventhandler.invalidreference.class`** = *classname*
> register an [invalid reference event
> handler](apidocs/org/apache/velocity/app/event/InvalidReferenceEventHandler.html).
-`eventhandler.methodexception.class = `*classname*
+**`eventhandler.methodexception.class`** = *classname*
> register a [method exception event
> handler](apidocs/org/apache/velocity/app/event/MethodExceptionEventHandler.html).
-`eventhandler.referenceinsertion.class = `*classname*
+**`eventhandler.referenceinsertion.class`** = *classname*
> register a [reference insertion event
> handler](apidocs/org/apache/velocity/app/event/ReferenceInsertionEventHandler.html).
-## Pluggable Introspection
+## Introspection
+
+Introspection is the process of mapping properties, methods and iterators of
VTL references to Java objects. The object responsible of the introspection
strategy in Velocity is called an *uberspector*.
-`runtime.introspector.uberspect =
org.apache.velocity.util.introspection.UberspectImpl`
+**`runtime.introspector.uberspect =
org.apache.velocity.util.introspection.UberspectImpl`**
> This property sets the 'Uberspector', the introspection package that handles
> all introspection strategies for Velocity. You can specify a comma-separated
> list of Uberspector classes, in which case all Uberspectors are chained. The
> default chaining behaviour is to return the first non-null value for each
> introspection call among all provided uberspectors. You can modify this
> behaviour (for instance to restrict access to some methods) by subclassing
> org.apache.velocity.util.introspection.AbstractChainableUberspector (or
> implementing directly
> org.apache.velocity.util.introspection.ChainableUberspector). This allows
> you to create more interesting rules or patterns for Uberspection, rather
> than just returning the first non-null value.
>
-> Some alternate Uberspectors are provided. Please refer to the [Customizing
Introspection](developer-guide.html#customizing-introspection) section for a
detailed list. You would for instance use `runtime.introspector.uberspect =
org.apache.velocity.util.introspection.SecureUberspector` to avoid template
authors to instanciate new classes or to use reflection, or use
`runtime.introspector.uberspect =
org.apache.velocity.util.introspection.UberspectImpl,
org.apache.velocity.util.introspection.UberspectPublicFields` to expose Java
public fields in your templates.
+> Some alternate Uberspectors are provided within the Velocity package. Please
refer to the [Customizing
Introspection](developer-guide.html#customizing-introspection) section for a
detailed list. You would for instance use `runtime.introspector.uberspect =
org.apache.velocity.util.introspection.SecureUberspector` to avoid template
authors to instanciate new classes or to use reflection, or use
`runtime.introspector.uberspect =
org.apache.velocity.util.introspection.UberspectImpl,
org.apache.velocity.util.introspection.UberspectPublicFields` to expose Java
public fields in your templates.
+
+**`runtime.conversion.handler.class =
org.apache.velocity.util.introspection.ConversionHandlerImpl`**
+> This configuration option is only taken into account by the default
uberspector (UberspectImpl) and its subclasses (like SecureUberspector). It can
be set to:
+>
+>- `none`: the only accepted conversions for method arguments will be the ones
accepted by Java, typically widening number conversions. This reflects the
behavior of Velocity 1.x.
+>- *classname*: the name of a class implementing the interface
[org.apache.velocity.util.introspection.ConversionHandler](apidocs/org/apache/velocity/util/introspection/ConversionHandler.html).
+>
+> The default conversion handler will try to convert values between all
number, boolean and string types. Failed conversions will throw a
MethodInvocationException (or call the registered MethodExceptionEventHandler,
if any). Watch out for conversions towards boolean: non-zero numbers and the
"true" String are true, everything else is false. This differs slighly from the
`#if($reference)` truthness rules, where all non-null numbers and all non-null
and non-empty strings are true.
## Context
-`context.autoreference.key = *name*`
+**`context.autoreference.key = <key name>`**
> This property has no default value. If present, the Context object will
> become accessible from the templates under the provided name. For instance,
> with the configuration "`context.autoreference.key = self`", then `$self`
> will contain the context itself. This feature is meant to be used for
> debugging purposes.
-## Pluggable Resource Manager and Resource Cache
-
-The Resource Manager is the main part of the resource (template and static
content) management system, and is responsible for taking application requests
for templates, finding them in the available resource loaders, and then
optionally caching the parsed template. The Resource Cache is the mechanism
that the Resource Manager uses to cache templates for quick reuse. While the
default versions of these two facilities are suitable for most applications,
for advanced users it now is possible to replace the default resource manager
and resource cache with custom implementations.
-
-A resource manager implementation must implement the
`org.apache.velocity.runtime.resource.ResourceManager` interface. A description
of the requirements of a resource manager is out of scope for this document.
Implementors are encouraged to review the default implementation. To configure
Velocity to load the replacement implementation, use the configuration key:
-
- resource.manager.class
-
-This key is also defined as a contstant
`RuntimeConstants.RESOURCE_MANAGER_CLASS`
-
-A resource cache implementation must implement the
`org.apache.velocity.runtime.resource.ResourceCache` interface As with the
resource manager, a description of the requirements of a resource manager is
out of scope for this document. Implementors are encouraged to review the
default implementation. To configure Velocity to load the replacement
implementation, use the configuration key:
-
- resource.manager.cache.class
-
-This key is also defined as a contstant
`RuntimeConstants.RESOURCE_MANAGER_CACHE_CLASS`
-
-A resource cache implementation may want to limit the cache size (rather than
providing an unbounded cache which could consume all available memory). To
configure Velocity to set the size for your cache, use the configuration key:
-
- resource.manager.cache.size
-
-This key is also defined as a contstant
`RuntimeConstants.RESOURCE_MANAGER_CACHE_SIZE`
-
## String Interning
-`runtime.string.interning = true`
+**`runtime.string.interning = true`**
> This property specifies whether to use Java (String
> interning)[https://en.wikipedia.org/wiki/String_interning] on identifiers.
> This may save some memory when set to true, and run a little bit faster when
> set to false.
## Configuration Examples
Modified: velocity/site/cms/trunk/content/engine/devel/developer-guide.mdtext
URL:
http://svn.apache.org/viewvc/velocity/site/cms/trunk/content/engine/devel/developer-guide.mdtext?rev=1754153&r1=1754152&r2=1754153&view=diff
==============================================================================
--- velocity/site/cms/trunk/content/engine/devel/developer-guide.mdtext
(original)
+++ velocity/site/cms/trunk/content/engine/devel/developer-guide.mdtext Tue Jul
26 16:21:03 2016
@@ -125,7 +125,7 @@ That's the basic pattern. It is very sim
## To Singleton Or Not To Singleton...
-As of Velocity 1.2 and later, developers now have two options for using the
Velocity engine, the singleton model and the separate instance model. The same
core Velocity code is used for both approaches, which are provided to make
Velocity easier to integrate into your Java application.
+Developers have two options for using the Velocity engine, the singleton model
and the separate instance model. The same core Velocity code is used for both
approaches, which are provided to make Velocity easier to integrate into your
Java application.
### Singleton Model
@@ -215,7 +215,7 @@ That's really all there is to basic cont
### Support for Iterative Objects for #foreach()
As a programmer, you have great freedom in the objects that you put into the
context. But as with most freedoms, this one comes with a little bit of
responsibility, so understand what Velocity supports, and any issues that may
arise. Velocity supports serveral types of collection types suitable for use
in the VTL `#foreach()` directive.
-+ `Object []` Regular object array, not much needs to be said here. Velocity
will internally wrap your array in a class that provides an Iterator interface,
but that shouldn't concern you as the programmer, or the template author. Of
more interest, is the fact that Velocity will now allow template authors to
treat arrays as fixed-length lists (as of Velocity 1.6). This means they may
call methods like `size()`, `isEmpty()` and `get(int)` on both arrays and
standard java.util.List instances without concerning themselves about the
difference.
++ `Object []` Regular object array, not much needs to be said here. Velocity
will internally wrap your array in a class that provides an Iterator interface,
but that shouldn't concern you as the programmer, or the template author. Of
more interest, is the fact that Velocity will now allow template authors to
treat arrays as fixed-length lists. This means they may call methods like
`size()`, `isEmpty()` and `get(int)` as well as the `empty` property on both
arrays and standard java.util.List instances without concerning themselves
about the difference.
+ `java.util.Collection` Velocity will use the `iterator()` method to get an
Iterator to use in the loop, so if you are implementing a Collection interface
on your object, please ensure that `iterator()` returns a working Iterator.
+ `java.util.Map ` Here, Velocity depends upon the `values()` method of the
interface to get a `Collection` interface, on which `iterator()` is called to
retrieve an Iterator for the loop.
+ `java.util.Iterator` USE WITH CAUTION: This is currently supported only
provisionally - the issue of concern is the 'non-resettablity' of the Iterator.
If a 'naked' Iterator is placed into the context, and used in more than one
#foreach(), subsequent #foreach() blocks after the first will fail, as the
Iterator doesn't reset.
@@ -299,7 +299,7 @@ Dealing with these cases if very straigh
+ The VTL RangeOperator [ 1..10 ] and ObjectArray ["a","b"] are
`java.util.ArrayList` objects when placed in the context or passed to methods.
Therefore, your methods that are designed to accept arrays created in the
template should be written with this in mind.
+ VTL Map references are unsurprisingly stored as `java.util.Map`.
+ Decimal numbers will be Doubles or BigDecimals in the context, integer
numbers will be Integer, Long, or BigIntegers, and strings will be, of course,
Strings.
-+ Velocity will properly 'narrow' args to method calls, so calling `setFoo(
int i )` with an int placed into the context via `#set()` will work fine.
++ Since version 2.0, Velocity will convert method arguments between all main
Java standard types (booleans, numbers and strings). If you want to revert to
the Velocity 1.x behavior, where provided conversions were restricted to
implicit Java conversions, you can set the property
`runtime.conversion.handler` to `none`.
### Other Context Issues
@@ -543,6 +543,8 @@ There are currently four kinds of resour
+ **DataSourceResourceLoader :** This loader will load resources from a
DataSource such as a database. This loader is only available under JDK 1.4 and
later. For more information on this loader, please see the javadoc for the
class `org.apache.velocity.runtime.resource.loader.DataSourceResourceLoader`.
+Advanced users may also want to replace the Resource Manager or the Resource
Cache: the Resource Manager is the main part of the resource (template and
static content) management system, and is responsible for taking application
requests for templates, finding them in the available resource loaders, and
then optionally caching the parsed template. The Resource Cache is the
mechanism that the Resource Manager uses to cache templates for quick reuse.
While the default versions of these two facilities are suitable for most
applications, it is possible to replace the default resource manager and
resource cache with custom implementations. See the (related configuration
options)[configuration.html#resource-management].
+
## Application Attributes
*Application Attributes* are name-value pairs that can be associated with a
RuntimeInstance (either via the `VelocityEngine` or the `Velocity` singleton)
and accessed from any part of the Velocity engine that has access to the
RuntimeInstance.
@@ -719,14 +721,14 @@ The following code shows how to register
## Customizing Introspection
-The [runtime.introspector.uberspect configuration
property](configuration.html#Pluggable-Introspection] property takes a list of
Uberspector class names that constitute the Velocity introspection chain. By
means it, you can change the way context objects are introspected at runtime to
map VTL properties and methods to Java calls.
+The [`runtime.introspector.uberspect` configuration
property](configuration.html#Pluggable-Introspection] property takes a list of
Uberspector class names that constitute the Velocity introspection chain. By
means it, you can change the way context objects are introspected at runtime to
map VTL properties and methods to Java calls.
Here is the list of provided uberspectors (which are found in the
(org.apache.velocity.util.introspection)[apidocs/org/apache/velocity/util/introspection/package-summary.html]
package).
### Standard Uberspectors
-
[UberspectImpl](apidocs/org/apache/velocity/util/introspection/UberspectImpl.html)
-> this is the default uberspector. It successively tries to resolve `$foo.bar`
into `foo.getBar()`, `foo.get('bar')` or `foo.isBar()` (plus some case
variants), and tries to match methods using arguments count and type.
+> this is the default uberspector. It successively tries to resolve `$foo.bar`
into `foo.getBar()`, `foo.get('bar')` or `foo.isBar()` (plus some case
variants), and tries to match methods using arguments count and type. Unless
you want to fondamentaly change the way Velocity resolves references methods
and properties, this uberspector should appear somewhere within the
introspection chain.
-
[ChainableUberspector](apidocs/org/apache/velocity/util/introspection/ChainableUberspector.html)
(interface) and
[AbstractChainableUberspector](apidocs/org/apache/velocity/util/introspection/AbstractChainableUberspector.html)
(meant to be inherited)
> A Chainable uberspector is an uberspector that wraps the previous
> uberspector in the introspection chain.
-
[LinkingUberspector](apidocs/org/apache/velocity/util/introspection/LinkingUberspector.html)
@@ -745,6 +747,48 @@ If an Uberspector implements the [Runtim
-
[UberspectPublicFields](apidocs/org/apache/velocity/util/introspection/UberspectPublicFields)
> This uberspector exposes the public fields of objects. It can be prepended
> or suffixed to other uberspectors, depending on whether you want to priorize
> or not public fields versus potentially matching methods.
+### Method arguments conversions
+
+Since Velocity 2.0, besides the default conversions implicitly provided by
Java (aka [automatic boxing and
unboxing](https://en.wikipedia.org/wiki/Object_type_%28object-oriented_programming%29),
and widening number conversions), method arguments will be converted as needed
by the UberspectorImpl or SecureUberspector using the following conversions:
+
+- boolean to number: `true` is converted to 1, false to 0
+- boolean to string: `true` and `false` are respectively converted to "true"
and "false"
+- number to boolean: zero numbers are converted to `false`, everything else to
`true`
+- number to string
+- string to boolean: "true" is converted to `true`, every other string
(including the null string) are converted to `false`
+- string to number: if the string does not represent a number or doesn't fit
into the expected number type, an exception is thrown
+- narrowing number conversion: if the number doesn't fit into the expected
number type, an exception is thrown
+
+You can provide a custom conversion handler class by use of the
`runtime.conversion.handler` property. The class must implement the
[`org.apache.Velocity.util.introspection.ConversionHandler`](apidocs/org/apache/velocity/util/introspection/ConversionHandler.html)
interface. Set it to `none` to only accept default Java conversions, as for
Velocity 1.x.
+
+You can also provide custom
[`Converter<T>`](apidocs/org/apache/velocity/util/introspection/Converter.html)
objects that handle a conversion towards a specific type:
+
+ package mypackage;
+
+ import java.util.Date;
+ import org.apache.velocity.util.introspection.*;
+
+ public class MyUberspector extends UberspectorImpl
+ {
+ public void init()
+ {
+ super.init();
+ getConversionHandler().addConverter(Integer.class, Date.class, new
ConvertToDate());
+ getConversionHandler().addConverter(Long.class, Date.class, new
ConvertToDate());
+ }
+
+ public static class ConvertToDate extends Converter<Date>
+ {
+ @Override
+ public Date convert(Object o)
+ {
+ return new Date(((Number)o).longValue());
+ }
+ }
+ }
+
+You'll then need to register your uberspector with
`runtime.introspection.uberspect = mypackage.MyUberspector`. Another approach
would be to inherit from ConversionHandlerImpl, add converters within its
constructor and register your conversion handler using the
`runtime.conversion.handler` configuration property.
+
## Template Encoding for Internationalization
Velocity allows you to specify the character encoding of your template
resources on a template by template basis. The normal resource API's have been
extended to take the encoding as an argument:
Modified: velocity/site/cms/trunk/content/engine/devel/left.nav
URL:
http://svn.apache.org/viewvc/velocity/site/cms/trunk/content/engine/devel/left.nav?rev=1754153&r1=1754152&r2=1754153&view=diff
==============================================================================
--- velocity/site/cms/trunk/content/engine/devel/left.nav (original)
+++ velocity/site/cms/trunk/content/engine/devel/left.nav Tue Jul 26 16:21:03
2016
@@ -12,10 +12,10 @@
* [Configuration](configuration.html)
* [Glossary](glossary.html)
* [Javadoc](apidocs/index.html)
+* [Upgrading](upgrading.html)
## Developers
* [License](license.html)
* [Changes](changes.html)
-* [Upgrading](upgrading.html)
* [Dependencies](dependencies.html)
* [Sources](source-repository.html)
* [Building](build.html)
Modified: velocity/site/cms/trunk/content/engine/devel/upgrading.mdtext
URL:
http://svn.apache.org/viewvc/velocity/site/cms/trunk/content/engine/devel/upgrading.mdtext?rev=1754153&r1=1754152&r2=1754153&view=diff
==============================================================================
--- velocity/site/cms/trunk/content/engine/devel/upgrading.mdtext (original)
+++ velocity/site/cms/trunk/content/engine/devel/upgrading.mdtext Tue Jul 26
16:21:03 2016
@@ -2,11 +2,13 @@ Title: Apache Velocity Engine - Upgradin
## Upgrading from earlier versions
-Release with the same major number (1.x) are intended to be drop-in
replacements. However, in most cases the versions of dependency jars must be
adjusted because newer versions of Velocity might require updates.
+This page details
-### Upgrading from Velocity 1.7.x to Velocity 2.0.x
+Release with the same major number (1.x, 2.x) are intended to be drop-in
replacements. However, in most cases the versions of dependency jars must be
adjusted because newer versions of Velocity might require updates.
-Behavior / API changes:
+## Upgrading from Velocity 1.7.x to Velocity 2.0.x
+
+### Behavior / API changes:
+ velocity is now using the SLF4J logging facade. Hence, all methods accepting
or returning a logger now use the org.slf4j.Logger object.
+ the internal Context API now enforces String keys everywhere, this may break
custom Context implementations at compile-time.
@@ -23,19 +25,20 @@ Behavior / API changes:
+ the MethodException event handler now receives an additional argument
providing template name and location infos.
+ all occurences of the class
org.apache.commons.collections.ExtendedProperties in the initialization API
have been replaced by org.apache.velocity.util.ExtProperties.
-VTL Syntax changes:
+### VTL Changes:
+ the hypen ( `-` ) cannot be used in variable names anymore
+ method arguments can be arithmetic expressions
++ method arguments are now converted as needed between all main basic Java
standard types (booleans, numbers and strings). If you want to revert to the
1.x behavior, set the property `runtime.conversion.handler = none`.
-Dependencies changes:
+### Dependencies changes:
+ Velocity now requires a JDK version of 1.7 or higher.
+ commons-lang, commons-collections and commons-logging aren't needed any more
at runtime.
+ there's a new runtime dependency, slf4j-api 1.7.12
+ you'll need an [SLF4J binding](dependencies.html)
-### Upgrading from Velocity 1.6.x to Velocity 1.7.x
+## Upgrading from Velocity 1.6.x to Velocity 1.7.x
There are no changes in the dependencies since Velocity 1.6
@@ -48,13 +51,13 @@ There are no changes in the dependencies
+ Removed obsolete Veltag (use VelocityViewTag in VelocityTools project)
+ Removed obsolete WebMacro conversion code.
-### Upgrading from Velocity 1.5.x to Velocity 1.6.x
+## Upgrading from Velocity 1.5.x to Velocity 1.6.x
+ [Commons Collections](http://commons.apache.org/collections/) has been
upgraded to version 3.2.1.
+ [Commons Lang](http://commons.apache.org/lang/) has been upgraded to version
2.4.
+ [Commons Logging](http://commons.apache.org/logging/) is required for
compiling and using CommonsLogLogChute.
-### Upgrading from Velocity 1.4 or earlier
+## Upgrading from Velocity 1.4 or earlier
+ [JDOM](http://www.jdom.org) has been upgraded to version 1.0.
+ [Commons Collections](http://jakarta.apache.org/commons/collections/) has
been upgraded to version 3.1.
Modified: velocity/site/cms/trunk/content/engine/devel/user-guide.mdtext
URL:
http://svn.apache.org/viewvc/velocity/site/cms/trunk/content/engine/devel/user-guide.mdtext?rev=1754153&r1=1754152&r2=1754153&view=diff
==============================================================================
--- velocity/site/cms/trunk/content/engine/devel/user-guide.mdtext (original)
+++ velocity/site/cms/trunk/content/engine/devel/user-guide.mdtext Tue Jul 26
16:21:03 2016
@@ -190,9 +190,9 @@ We might expect these methods to return
$book.setTitle( "Homage to Catalonia" )
## Can't pass a parameter
-As of Velocity 1.6, all array references are now "magically" treated as if
they are fixed-length lists. This means that you can call java.util.List
methods on array references. So, if you have a reference to an array (let's
say this one is a String[] with three values), you can do:
+All array references are treated as if they are fixed-length lists. This means
that you can call java.util.List methods and properties on array references.
So, if you have a reference to an array (let's say this one is a String[] with
three values), you can do:
- $myarray.isEmpty()
+ $myarray.isEmpty() or $myarray.empty
$myarray.size()
@@ -200,7 +200,7 @@ As of Velocity 1.6, all array references
$myarray.set(1, 'test')
-Also new in Velocity 1.6 is support for vararg methods. A method like
`azpublic void setPlanets(String... planets)` or even just `public void
setPlanets(String[] planets)` can now accept any number of arguments when
called in a template.
+Velocity also supports vararg methods. A method like `azpublic void
setPlanets(String... planets)` or even just `public void setPlanets(String[]
planets)` can now accept any number of arguments when called in a template.
$sun.setPlanets('Earth', 'Mars', 'Neptune')
@@ -209,6 +209,8 @@ Also new in Velocity 1.6 is support for
$sun.setPlanets()
## Will just pass in an empty, zero-length array
+As of Velocity 2.0, method calls now provides implicit conversions between all
Java basic builtin types: numbers, booleans and strings.
+
### Property Lookup Rules
As was mentioned earlier, properties often refer to methods of the parent
object. Velocity is quite clever when figuring out which method corresponds to
a requested property. It tries out different alternatives based on several
established naming conventions. The exact lookup sequence depends on whether or
not the property name starts with an upper-case letter. For lower-case names,
such as *$customer.address*, the sequence is
Modified: velocity/site/cms/trunk/content/engine/index.mdtext
URL:
http://svn.apache.org/viewvc/velocity/site/cms/trunk/content/engine/index.mdtext?rev=1754153&r1=1754152&r2=1754153&view=diff
==============================================================================
--- velocity/site/cms/trunk/content/engine/index.mdtext (original)
+++ velocity/site/cms/trunk/content/engine/index.mdtext Tue Jul 26 16:21:03 2016
@@ -9,12 +9,12 @@ Velocity permits you to use a simple yet
The Velocity engine subproject contains the documentation to get started using
the Velocity templating language and embedding Velocity into your own
applications. Please select [the last released version](1.7) to get started.
Once you are more familiar with Velocity or if you need a feature not yet
released, you can check out the [Development Site](devel).
+ [Engine 1.7 Release](1.7) pages.
-+ [Engine Development Version](devel/) pages.
++ [Engine Development (2.x) Version](devel/) pages.
## Older Releases
+ [Engine 1.6.2 Release](1.6.2)
+ [Engine 1.6.1 Release](1.6.1)
+ [Engine 1.6 Release](1.6)
-+ [Engine 1.6 Release](1.5)
-+ [Engine 1.6 Release](1.4)
++ [Engine 1.5 Release](1.5)
++ [Engine 1.4 Release](1.4)
