<?xml version="1.0"?>

<!--
	description:

		"Available Tasks"

	library: "Gobo Eiffel Ant"
	copyright: "Copyright (c) 2002, Sven Ehrke and others"
	license: "Eiffel Forum License v2 (see forum.txt)"
	date: "$Date: 2005/07/07 13:34:11 $"
	revision: "$Revision: 1.6 $"
-->

<chapter xmlns="http://www.gobosoft.com/eiffel/gobo/documentation" id="available_task">
<chapterinfo>
	<copyright>
		<year>2002-2005</year>
		<holder>Sven Ehrke</holder>
	</copyright>
	<author>
		<firstname>Sven</firstname><surname>Ehrke</surname>
	</author>
	<email>ericb@gobosoft.com</email>
	<date>7 July 2005</date>
</chapterinfo>

	<title>available</title>

	<section id="available_description">
		<title>Description</title>
		<para>
			Checks if specified resource is available and sets the value of a variable depending on the result.
		</para>
	</section>

	<section id="available_parameters">
		<title>Parameters</title>

		<variablelist>
			<varlistentry>
				<term>resource</term>
				<listitem>
					<para><emphasis>Description: </emphasis>Name of a resource. Currently files and directories are supported</para>
				</listitem>
				<listitem>
					<para><emphasis>Domain: </emphasis>Valid filename/directoryname</para>
				</listitem>
				<listitem>
					<para><emphasis>Default: </emphasis>-</para>
				</listitem>
			</varlistentry>

			<varlistentry>
				<term>variable</term>
				<listitem>
					<para><emphasis>Description: </emphasis>variable which reflects the result</para>
				</listitem>
				<listitem>
					<para><emphasis>Domain: </emphasis>valid variable name</para>
				</listitem>
				<listitem>
					<para><emphasis>Default: </emphasis>-</para>
				</listitem>
			</varlistentry>

			<varlistentry>
				<term>true_value</term>
				<listitem>
					<para><emphasis>Description: </emphasis>result value of positive comparison</para>
				</listitem>
				<listitem>
					<para><emphasis>Domain: </emphasis>-</para>
				</listitem>
				<listitem>
					<para><emphasis>Default: </emphasis>true</para>
				</listitem>
			</varlistentry>

			<varlistentry>
				<term>false_value</term>
				<listitem>
					<para><emphasis>Description: </emphasis>result value of negative comparison</para>
				</listitem>
				<listitem>
					<para><emphasis>Domain: </emphasis>-</para>
				</listitem>
				<listitem>
					<para><emphasis>Default: </emphasis>false</para>
				</listitem>
			</varlistentry>

		</variablelist>
	</section>

	<section id="available_specification">
		<title>RNG Specification</title>

		<programlisting><![CDATA[
  <define name="available">
    <element name="available">
      <ref name="dir_if_unless"/>
      <attribute name="resource"/>
      <attribute name="variable"/>
      <optional>
        <attribute name="true_value"/>
      </optional>
      <optional>
        <attribute name="false_value"/>
      </optional>
    </element>
  </define>
]]>
	</programlisting>
	</section>

	<section id="available_examples">
		<title>Examples</title>
	<programlisting><![CDATA[
  <available resource="${GOBO}/readme.txt" variable="available"/>
]]>
	</programlisting>
	</section>

</chapter>
