| <!-- |
| Licensed to the Apache Software Foundation (ASF) under one or more |
| contributor license agreements. See the NOTICE file distributed with |
| this work for additional information regarding copyright ownership. |
| The ASF licenses this file to You under the Apache License, Version 2.0 |
| (the "License"); you may not use this file except in compliance with |
| the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| --> |
| <html> |
| |
| <head> |
| <meta http-equiv="Content-Language" content="en-us"> |
| <link rel="stylesheet" type="text/css" href="../stylesheets/style.css"> |
| <title>Available Task</title> |
| </head> |
| |
| <body> |
| |
| <h2><a name="available">Available</a></h2> |
| <h3>Description</h3> |
| <p>Sets a property if a resource is available at runtime. This resource can be a |
| file, a directory, a class in the classpath, or a JVM system resource.</p> |
| <p>If the resource is present, the property value is set to true by |
| default; otherwise, the property is not set. You can set the value to |
| something other than the default by specifying the <code>value</code> attribute.</p> |
| <p>Normally, this task is used to set properties that are useful to avoid target |
| execution depending on system parameters.</p> |
| <h3>Parameters</h3> |
| <table border="1" cellpadding="2" cellspacing="0"> |
| <tr> |
| <td valign="top"><b>Attribute</b></td> |
| <td valign="top"><b>Description</b></td> |
| <td align="center" valign="top"><b>Required</b></td> |
| </tr> |
| <tr> |
| <td valign="top">property</td> |
| <td valign="top">The name of the property to set.</td> |
| <td valign="top" align="center">Yes</td> |
| </tr> |
| <tr> |
| <td valign="top">value</td> |
| <td valign="top">The value to set the property to. Defaults to "true".</td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">classname</td> |
| <td valign="top">The class to look for in the classpath.</td> |
| <td valign="middle" align="center" rowspan="3">Yes</td> |
| </tr> |
| <tr> |
| <td valign="top">file</td> |
| <td valign="top">The file to look for.</td> |
| </tr> |
| <tr> |
| <td valign="top">resource</td> |
| <td valign="top">The resource to look for in the JVM.</td> |
| </tr> |
| <tr> |
| <td valign="top">classpath</td> |
| <td valign="top">The classpath to use when looking up <code>classname</code> or <code>resource</code>.</td> |
| <td align="center" valign="top">No</td> |
| </tr> |
| <tr> |
| <td valign="top">filepath</td> |
| <td valign="top">The path to use when looking up <code>file</code>.</td> |
| <td align="center" valign="top">No</td> |
| </tr> |
| <tr> |
| <td valign="top">classpathref</td> |
| <td valign="top">The classpath to use, given as a <a href="../using.html#references">reference</a> to a path defined elsewhere.</td> |
| <td align="center" valign="top">No</td> |
| </tr> |
| <tr> |
| <td valign="top">type</td> |
| <td valign="top">The type of <code>file</code> to look for, either a directory (<code>type="dir"</code>) or a file |
| (<code>type="file"</code>). If not set, the property will be set if the name specified in the <code>file</code> |
| attribute exists as either a file or a directory.</td> |
| <td align="center" valign="top">No</td> |
| </tr> |
| <tr> |
| <td valign="top">ignoresystemclasses</td> |
| <td valign="top">Ignore Ant's runtime classes, using only the specified |
| classpath. Only affects the "classname" attribute. Defaults to "false"</td> |
| <td align="center" valign="top">No</td> |
| </tr> |
| <tr> |
| <td valign="top">searchparents</td> |
| <td valign="top">This contains the behaviour of the "file" type. |
| If true, the available task will, when |
| searching for a file, search not only the directories specified but |
| will also search the parent directories of those |
| specified. |
| If false, only the directories specified will be searched. |
| Defaults to "false". |
| <em>Since Ant 1.7</em> |
| </td> |
| <td align="center" valign="top">No</td> |
| </tr> |
| </table> |
| <h3>Parameters specified as nested elements</h3> |
| <h4>classpath</h4> |
| <p><code>Available</code>'s <code>classpath</code> attribute is a <a |
| href="../using.html#path">path-like structure</a> and can also be set via a nested |
| <code><classpath></code> element.</p> |
| <h4>filepath</h4> |
| <p><code>Available</code>'s <code>filepath</code> attribute is a <a |
| href="../using.html#path">path-like structure</a> and can also be set via a nested |
| <code><filepath></code> element.</p> |
| <h3>Examples</h3> |
| <blockquote><pre> |
| <available classname="org.whatever.Myclass" property="Myclass.present"/> |
| </pre></blockquote> |
| <p>sets the <code>Myclass.present</code> property to the value "true" |
| if the class <code>org.whatever.Myclass</code> is found in Ant's classpath.</p> |
| <blockquote><pre> |
| <property name="jaxp.jar" value="./lib/jaxp11/jaxp.jar"/> |
| <available file="${jaxp.jar}" property="jaxp.jar.present"/> |
| </pre></blockquote> |
| <p>sets the <code>jaxp.jar.present</code> property to the value "true" |
| if the file <code>./lib/jaxp11/jaxp.jar</code> is found.</p> |
| <blockquote><pre> |
| <available file="/usr/local/lib" type="dir" |
| property="local.lib.present"/> |
| </pre></blockquote> |
| <p>sets the <code>local.lib.present</code> property to the value "true" |
| if the directory <code>/usr/local/lib</code> is found.</p> |
| <blockquote><pre> |
| ...in project ... |
| <property name="jaxp.jar" value="./lib/jaxp11/jaxp.jar"/> |
| <path id="jaxp" location="${jaxp.jar}"/> |
| ...in target ... |
| <available classname="javax.xml.transform.Transformer" |
| classpathref="jaxp" property="jaxp11.present"/> |
| </pre></blockquote> |
| <p>sets the <code>jaxp11.present</code> property to the value "true" |
| if the class <code>javax.xml.transform.Transformer</code> is found in the classpath referenced by <code>jaxp</code> (in this case, <code>./lib/jaxp11/jaxp.jar</code>). |
| </p> |
| <blockquote><pre> |
| <available property="have.extras" resource="extratasks.properties"> |
| <classpath> |
| <pathelement location="/usr/local/ant/extra.jar" /> |
| </classpath> |
| </available> |
| </pre></blockquote> |
| <p>sets the <code>have.extras</code> property to the value "true" |
| if the resource-file <code>extratasks.properties</code> is found. |
| </p> |
| |
| |
| </body> |
| </html> |
| |
