donaldp 02/03/30 21:17:27
Added: proposal/myrmidon/docs configuring.html
proposal/myrmidon/src/xdocs configuring.xml
Log:
Add a basic page about configuring tasks in myrmidon.
Revision Changes Path
1.1 jakarta-ant/proposal/myrmidon/docs/configuring.html
Index: configuring.html
===================================================================
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
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charset=iso-8859-1"/>
<meta name="author" value="Peter Donald">
<meta name="email" value="[EMAIL PROTECTED]">
<title>Apache Myrmidon - On Task Configuring in Ant2</title>
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<a href="http://jakarta.apache.org";><img
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<td valign="bottom"><div align="right"><b><font size="+3"
color="#525D76">Apache Myrmidon</font></b></div></td>
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<td valign="top" nowrap="true">
<p><strong>Myrmidon</strong></p>
<ul>
<li> <a href="./index.html">Introduction</a>
</li>
<li> <a href="./getinvolved.html">Get Involved</a>
</li>
<li> <a href="./user.html">Building Myrmidon</a>
</li>
<li> <a href="./todo.html">Todo List</a>
</li>
</ul>
<p><strong>User Guide</strong></p>
<ul>
<li> <a href="./buildfile.html">Build file</a>
</li>
<li> <a href="./vfs.html">Virtual File System</a>
</li>
<li> <a href="./ant1compat.html">Ant1 Compatibility Layer</a>
</li>
<li> <a href="./differences.html">Differences to Ant1</a>
</li>
<li> <a href="./task.html">My First Task</a>
</li>
</ul>
<p><strong>Extending Ant</strong></p>
<ul>
<li> <a href="./configuring.html">Configuration HOWTO</a>
</li>
<li> <a href="./converter.html">Converter HOWTO</a>
</li>
<li> <a href="./type.html">Type HOWTO</a>
</li>
<li> <a href="./classloader.html">ClassLoader HOWTO</a>
</li>
<li> <a href="./librarys.html">Library HOWTO</a>
</li>
</ul>
<p><strong>Container Design</strong></p>
<ul>
</ul>
</td>
<td align="left" valign="top">
<table border="0" cellspacing="0" cellpadding="2" width="100%">
<tr><td bgcolor="#525D76">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Introduction"><strong>Introduction</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>This section will describe in detail the mechanism
via which tasks are
configured. Configuration is the name given to the stage in tasks
lifecycle via which the XML representation is mapped onto the
task
object.</p>
</blockquote>
</td></tr>
</table>
<table border="0" cellspacing="0" cellpadding="2" width="100%">
<tr><td bgcolor="#525D76">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Names"><strong>Names</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>When mapping the XML representation on to the task
object you
need to be able map the names as they appear in the XML to the
names as they appear in the Java code. The process is for
generating
a java name from the xml name is as follows.</p>
<ol>
<li>Capitalize the first character of name.</li>
<li>Find any '-' characters in XML name and remove character and
capitalize the following letter. (And there must be a following
letter)</li>
</ol>
<p>Some example mappings;</p>
<div align="left">
<table cellspacing="4" cellpadding="0" border="0">
<tr>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
<td bgcolor="#023264" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
</tr>
<tr>
<td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
<td bgcolor="#ffffff"><pre>
my-name ===> MyName
aString ===> AString
Basedir ===> Basedir
baseDir ===> BaseDir
url ===> Url</pre></td>
<td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
</tr>
<tr>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
<td bgcolor="#023264" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
</tr>
</table>
</div>
<p>Note that the above transformation is
lossy and as such the
following XML names all map to the same Java name. The ant1.x
mapping
is similarly lossy and in practice this has not been an issue.</p>
<div align="left">
<table cellspacing="4" cellpadding="0" border="0">
<tr>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
<td bgcolor="#023264" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
</tr>
<tr>
<td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
<td bgcolor="#ffffff"><pre>
base-dir ===> BaseDir
Base-dir ===> BaseDir
baseDir ===> BaseDir
BaseDir ===> BaseDir</pre></td>
<td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
</tr>
<tr>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
<td bgcolor="#023264" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
</tr>
</table>
</div>
<p><i>NOTE: We should really resolve this and
either disallow '-' characters
or disallow uppercase or something. (PD)</i></p>
</blockquote>
</td></tr>
</table>
<table border="0" cellspacing="0" cellpadding="2" width="100%">
<tr><td bgcolor="#525D76">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Resolving Values"><strong>Resolving Values</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>The first stage of mapping the XML representation
to the task
is resolving all text data. The text data that needs to be
resolved
include the values of attributes and the content.</p>
<p>Resolution consists of expanding any
property references in the text
data. Property references are identified as starting with the
token
"${" and finishing with another "}" token. The text
in between is the name of a property. The value of the property
replaces
the sequence of text starting with the "${" token and finishing
with the "}" token.</p>
<p>Note that the value of the property may
not be a string. If the text data
contains text (or other property references) to either side of
the property
reference then it must be <a href="converter.html">converted</a>
to a
String.</p>
</blockquote>
</td></tr>
</table>
<table border="0" cellspacing="0" cellpadding="2" width="100%">
<tr><td bgcolor="#525D76">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Modeller"><strong>Modeller</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>Currently the representation of object are stored
in a hierarchial
tree of <code>org.apache.myrmidon.api.metadata.ModelElement</code>
objects. Each ModelElement has a number of attributes and can have
either content or sub-elements.</p>
<p>In most cases it is the responsibility of
the runtime to map
the ModelElement onto an object. However in some cases it may be
useful
for the object to get access to it's own model and for it to
explicitly
manage it's own configuration. In this case the object should
implement
the <code>org.apache.myrmidon.api.metadata.Modeller</code>
interface
which will provide the mechanism for the object to receive its
own
representation and configure itself.</p>
<p>Note that the Modeller mechanism should be
avoided if possible
as it adds considerable complexity to the implementing object.</p>
</blockquote>
</td></tr>
</table>
<table border="0" cellspacing="0" cellpadding="2" width="100%">
<tr><td bgcolor="#525D76">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Attributes"><strong>Attributes</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>To map an XML attribute on to a Java object, the
name of the
attribute is mapped to a java name and prefixed with the string
"set". The resulting string is then used to look up a
method with a single parameter.</p>
<p>For example, for the attribute "world"
would result
in a lookup of a method named "setWorld" with a single
parameter.</p>
<p>If multiple methods were matched during
the lookup then an
exception is thrown indicating ambiguity. Theres is an exception
to this rule that allows 2 methods to be matched if one of the
methods takes a <code>java.lang.String</code> parameter. The
method
that has the <code>java.lang.String</code> parameter is ignored
and
the other method would be chosen. This exception is allowed as it
is
common practice for a task to evolve from String parameters to
more
strongly typed parameters.</p>
<p>The resolved text data of the attribute
must be
<a href="converter.html">converted</a> to the type of the matched
methods parameter. For example, if the "setWorld" method
took a parameter of type <code>java.io.File</code> then the
resolved
text data must be converted into a <code>java.io.File</code>. The
conversion is done by the Converter architecture that is more
fully
described in the <a href="converter.html">Converter HOWTO</a>.</p>
<p>After the value is converted to the
correct type the method is
invoked with the converted value.</p>
</blockquote>
</td></tr>
</table>
<table border="0" cellspacing="0" cellpadding="2" width="100%">
<tr><td bgcolor="#525D76">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Content"><strong>Content</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>The XML representation of object can have either
have nested
elements or nested text (content) but not both. To add the content
to an object a method named "content" with one parameter is
looked
up. The resolved text data for content is then
<a href="converter.html">converted</a> to the type of the
parameter
and passed in via the method.</p>
</blockquote>
</td></tr>
</table>
<table border="0" cellspacing="0" cellpadding="2" width="100%">
<tr><td bgcolor="#525D76">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Element"><strong>Element</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>Mapping an ModelElement onto a java object is a
series of steps.
If the ModelElement name ends with the string "-ref" then
it is treated as a reference element - see the <em>Referrenced
Elements</em> section. Otherwise, the element is first attempted
to
be mapped as a <em>Named Element</em> and if no match is found
via
that method it tries to treat the element as a <em>Typed
Element</em>.</p>
<table border="0" cellspacing="0"
cellpadding="2" width="100%">
<tr><td bgcolor="#828DA6">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Named Elements"><strong>Named Elements</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>To map a named ModelElement on to a Java object,
the name of
the element is mapped to a java name and prefixed with the string
"add". The resulting string is then used to look up a
method with a single parameter.</p>
<p>For example, for the attribute "geometry"
would result
in a lookup of a method named "addGeometry" with a single
parameter. If multiple methods were matched during the lookup
then an
exception is thrown indicating ambiguity. If no methods were
found that
match name then skip down to configuring "typed" elements.</p>
<p>The type of the methods single parameter
is then examined to determine
what happens next. There are two valid situations, if neither of
these are
satisfied, then an exception is thrown.</p>
<ul>
<li>The parameters type is
<code>org.apache.myrmidon.api.metadata.ModelElement</code></li>
<li>The parameters type is a concrete class</li>
</ul>
<p>1. If the parameter has a type of
<code>org.apache.myrmidon.api.metadata.ModelElement</code>
then the un-modified model representation of element is passed to
object by invoking
the adder method.</p>
<p>2. If the parameters type is concrete then
an instance of the parameter is
instantiated using the default constructor. This created object
is then configured
in the same manner as task using the elements representation as
the model. After
the object is configured it is passed into object by invoking the
adder method.</p>
</blockquote>
</td></tr>
</table>
<table border="0" cellspacing="0"
cellpadding="2" width="100%">
<tr><td bgcolor="#828DA6">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Referrenced Elements"><strong>Referrenced
Elements</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>A referenced element is one that has a name ending
in
"-ref" and has a single attribute "name"
and no content or child elements.</p>
<p>The value of the "name" attribute is the
name of a property.
The value of this property is retrieved from the TaskContext.</p>
<p>Like with <em>Named Elements</em> the name
of the element (minus
the "-ref" part) is mapped to a java name and prefixed with the
string
"add". The resulting string is then used to look up a
method with a single parameter. If multiple methods were matched
during the lookup then an
exception is thrown indicating ambiguity.</p>
<p>The value retrieved from the TaskContext
is then converted to the type
of the methods parameter and the add method is invoked with the
converted value.</p>
<p>An example usage is the following;</p>
<div align="left">
<table cellspacing="4" cellpadding="0" border="0">
<tr>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
<td bgcolor="#023264" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
</tr>
<tr>
<td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
<td bgcolor="#ffffff"><pre>
<my-task ...>
<classpath-ref name="project.class.path"/>
</my-task>
</pre></td>
<td bgcolor="#023264" width="1"><img src="/images/void.gif" width="1"
height="1" vspace="0" hspace="0" border="0"/></td>
</tr>
<tr>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
<td bgcolor="#023264" height="1"><img src="/images/void.gif"
width="1" height="1" vspace="0" hspace="0" border="0"/></td>
<td bgcolor="#023264" width="1" height="1"><img
src="/images/void.gif" width="1" height="1" vspace="0" hspace="0"
border="0"/></td>
</tr>
</table>
</div>
</blockquote>
</td></tr>
</table>
<table border="0" cellspacing="0"
cellpadding="2" width="100%">
<tr><td bgcolor="#828DA6">
<font color="#ffffff" face="arial,helvetica,sanserif">
<a name="Typed Elements"><strong>Typed Elements</strong></a>
</font>
</td></tr>
<tr><td>
<blockquote>
<p>"Typed" elements can also be added to an object. A
typed element
is one in which the name of the element actually refers to a type
rather than the
name of the adder to call.</p>
<p>For example, you may wish to allow a task
to add arbitrary instances of the
Condition role to a task. So instead of adding methods such as
<code>addAnd(AndCondition)</code>,
<code>addOr(OrCondition)</code> and
<code>addXor(XorCondition)</code> you can instead add a single
method
<code>add(Condition)</code>. This vastly simplifies the amount of
work required
to write tasks that take conditions. More importantly it allows
end-users to
extend the number of elements selected by task. For instance if
the user wanted
a "nand" condition they could write the Nand type use it in their
build
file. For a discussion on roles and types see the <a
href="types.html">Types
HOWTO</a>.</p>
<p>To use a Typed adder there must be a
single method named "add" that
has a single parameter. The parameter <em>MUST</em> be an
abstract interface and
must be registered as a role. The name of the element is then
used to lookup the
a type in the TypeManager with a role matching the interface
name.</p>
<p>For example if an element named "nand" was
added to an object that had
an adder with the signature <code>void add( Condition condition
)</code> then
the type named "nand" in the role "Condition" would be looked up.
An instance of the type would then be created using the default
constructor and the
created object would be configured and then adder to object using
adder.</p>
</blockquote>
</td></tr>
</table>
</blockquote>
</td></tr>
</table>
</td>
</tr>
<!-- FOOTER -->
<tr><td colspan="2">
<hr noshade="" size="1"/>
</td></tr>
<tr><td colspan="2">
<div align="center"><font color="#525D76" size="-1"><em>
Copyright © 2000-2002, Apache Software Foundation
</em></font></div>
</td></tr>
</table>
</body>
</html>
<!-- end the processing -->
1.1 jakarta-ant/proposal/myrmidon/src/xdocs/configuring.xml
Index: configuring.xml
===================================================================
<?xml version="1.0"?>
<document>
<properties>
<title>On Task Configuring in Ant2</title>
<author email="[EMAIL PROTECTED]">Peter Donald</author>
</properties>
<body>
<section name="Introduction">
<p>This section will describe in detail the mechanism via which
tasks are
configured. Configuration is the name given to the stage in tasks
lifecycle via which the XML representation is mapped onto the
task
object.</p>
</section>
<section name="Names">
<p>When mapping the XML representation on to the task object you
need to be able map the names as they appear in the XML to the
names as they appear in the Java code. The process is for
generating
a java name from the xml name is as follows.</p>
<ol>
<li>Capitalize the first character of name.</li>
<li>Find any '-' characters in XML name and remove character and
capitalize the following letter. (And there must be a following
letter)</li>
</ol>
<p>Some example mappings;</p>
<source>
my-name ===> MyName
aString ===> AString
Basedir ===> Basedir
baseDir ===> BaseDir
url ===> Url</source>
<p>Note that the above transformation is lossy and as such the
following XML names all map to the same Java name. The ant1.x
mapping
is similarly lossy and in practice this has not been an issue.</p>
<source>
base-dir ===> BaseDir
Base-dir ===> BaseDir
baseDir ===> BaseDir
BaseDir ===> BaseDir</source>
<p><i>NOTE: We should really resolve this and either disallow '-'
characters
or disallow uppercase or something. (PD)</i></p>
</section>
<section name="Resolving Values">
<p>The first stage of mapping the XML representation to the task
is resolving all text data. The text data that needs to be
resolved
include the values of attributes and the content.</p>
<p>Resolution consists of expanding any property references in
the text
data. Property references are identified as starting with the
token
"${" and finishing with another "}" token.
The text
in between is the name of a property. The value of the property
replaces
the sequence of text starting with the "${" token and
finishing
with the "}" token.</p>
<p>Note that the value of the property may not be a string. If
the text data
contains text (or other property references) to either side of
the property
reference then it must be <a href="converter.html">converted</a>
to a
String.</p>
</section>
<section name="Modeller">
<p>Currently the representation of object are stored in a
hierarchial
tree of <code>org.apache.myrmidon.api.metadata.ModelElement</code>
objects. Each ModelElement has a number of attributes and can have
either content or sub-elements.</p>
<p>In most cases it is the responsibility of the runtime to map
the ModelElement onto an object. However in some cases it may be
useful
for the object to get access to it's own model and for it to
explicitly
manage it's own configuration. In this case the object should
implement
the <code>org.apache.myrmidon.api.metadata.Modeller</code>
interface
which will provide the mechanism for the object to receive its
own
representation and configure itself.</p>
<p>Note that the Modeller mechanism should be avoided if possible
as it adds considerable complexity to the implementing object.</p>
</section>
<section name="Attributes">
<p>To map an XML attribute on to a Java object, the name of the
attribute is mapped to a java name and prefixed with the string
"set". The resulting string is then used to look up a
method with a single parameter.</p>
<p>For example, for the attribute "world" would result
in a lookup of a method named "setWorld" with a single
parameter.</p>
<p>If multiple methods were matched during the lookup then an
exception is thrown indicating ambiguity. Theres is an exception
to this rule that allows 2 methods to be matched if one of the
methods takes a <code>java.lang.String</code> parameter. The
method
that has the <code>java.lang.String</code> parameter is ignored
and
the other method would be chosen. This exception is allowed as it
is
common practice for a task to evolve from String parameters to
more
strongly typed parameters.</p>
<p>The resolved text data of the attribute must be
<a href="converter.html">converted</a> to the type of the matched
methods parameter. For example, if the "setWorld" method
took a parameter of type <code>java.io.File</code> then the
resolved
text data must be converted into a <code>java.io.File</code>. The
conversion is done by the Converter architecture that is more
fully
described in the <a href="converter.html">Converter HOWTO</a>.</p>
<p>After the value is converted to the correct type the method is
invoked with the converted value.</p>
</section>
<section name="Content">
<p>The XML representation of object can have either have nested
elements or nested text (content) but not both. To add the content
to an object a method named "content" with one parameter is
looked
up. The resolved text data for content is then
<a href="converter.html">converted</a> to the type of the
parameter
and passed in via the method.</p>
</section>
<section name="Element">
<p>Mapping an ModelElement onto a java object is a series of
steps.
If the ModelElement name ends with the string "-ref"
then
it is treated as a reference element - see the <em>Referrenced
Elements</em> section. Otherwise, the element is first attempted
to
be mapped as a <em>Named Element</em> and if no match is found
via
that method it tries to treat the element as a <em>Typed
Element</em>.</p>
<subsection name="Named Elements">
<p>To map a named ModelElement on to a Java object, the name of
the element is mapped to a java name and prefixed with the string
"add". The resulting string is then used to look up a
method with a single parameter.</p>
<p>For example, for the attribute "geometry" would
result
in a lookup of a method named "addGeometry" with a
single
parameter. If multiple methods were matched during the lookup
then an
exception is thrown indicating ambiguity. If no methods were
found that
match name then skip down to configuring "typed"
elements.</p>
<p>The type of the methods single parameter is then examined to
determine
what happens next. There are two valid situations, if neither of
these are
satisfied, then an exception is thrown.</p>
<ul>
<li>The parameters type is
<code>org.apache.myrmidon.api.metadata.ModelElement</code></li>
<li>The parameters type is a concrete class</li>
</ul>
<p>1. If the parameter has a type of
<code>org.apache.myrmidon.api.metadata.ModelElement</code>
then the un-modified model representation of element is passed to
object by invoking
the adder method.</p>
<p>2. If the parameters type is concrete then an instance of the
parameter is
instantiated using the default constructor. This created object
is then configured
in the same manner as task using the elements representation as
the model. After
the object is configured it is passed into object by invoking the
adder method.</p>
</subsection>
<subsection name="Referrenced Elements">
<p>A referenced element is one that has a name ending in
"-ref" and has a single attribute "name"
and no content or child elements.</p>
<p>The value of the "name" attribute is the name of a
property.
The value of this property is retrieved from the TaskContext.</p>
<p>Like with <em>Named Elements</em> the name of the element
(minus
the "-ref" part) is mapped to a java name and prefixed
with the string
"add". The resulting string is then used to look up a
method with a single parameter. If multiple methods were matched
during the lookup then an
exception is thrown indicating ambiguity.</p>
<p>The value retrieved from the TaskContext is then converted to
the type
of the methods parameter and the add method is invoked with the
converted value.</p>
<p>An example usage is the following;</p>
<source><![CDATA[
<my-task ...>
<classpath-ref name="project.class.path"/>
</my-task>
]]></source>
</subsection>
<subsection name="Typed Elements">
<p>"Typed" elements can also be added to an object. A
typed element
is one in which the name of the element actually refers to a type
rather than the
name of the adder to call.</p>
<p>For example, you may wish to allow a task to add arbitrary
instances of the
Condition role to a task. So instead of adding methods such as
<code>addAnd(AndCondition)</code>,
<code>addOr(OrCondition)</code> and
<code>addXor(XorCondition)</code> you can instead add a single
method
<code>add(Condition)</code>. This vastly simplifies the amount of
work required
to write tasks that take conditions. More importantly it allows
end-users to
extend the number of elements selected by task. For instance if
the user wanted
a "nand" condition they could write the Nand type use
it in their build
file. For a discussion on roles and types see the <a
href="types.html">Types
HOWTO</a>.</p>
<p>To use a Typed adder there must be a single method named
"add" that
has a single parameter. The parameter <em>MUST</em> be an
abstract interface and
must be registered as a role. The name of the element is then
used to lookup the
a type in the TypeManager with a role matching the interface
name.</p>
<p>For example if an element named "nand" was added to
an object that had
an adder with the signature <code>void add( Condition condition
)</code> then
the type named "nand" in the role "Condition"
would be looked up.
An instance of the type would then be created using the default
constructor and the
created object would be configured and then adder to object using
adder.</p>
</subsection>
</section>
</body>
</document>
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