Question

I need to retrieve some values from an HTML file. I need to use Ant so I can use these values in other parts of my script.

Can this even be achieved in Ant?

Answer 1

As stated in the other answers you can’t do this in “pure” XML. You need to embed a programming language. My personal favourite is Groovy, it’s integration with ANT is excellent.

Here’s a sample which retrieves the logo URL, from the groovy homepage:

parse:

print:
     [echo] 
     [echo]         Logo URL: http://groovy.codehaus.org/images/groovy-logo-medium.png
     [echo]     

build.xml

Build uses the ivy plug-in to retrieve all 3rd party dependencies.

<project name="demo" default="print" xmlns:ivy="antlib:org.apache.ivy.ant">

    <target name="resolve">
        <ivy:resolve/>
        <ivy:cachepath pathid="build.path" conf="build"/>
    </target>

    <target name="parse" depends="resolve">
        <taskdef name="groovy" classname="org.codehaus.groovy.ant.Groovy" classpathref="build.path"/>

        <groovy>
        import org.htmlcleaner.*

        def address = 'http://groovy.codehaus.org/'

        // Clean any messy HTML
        def cleaner = new HtmlCleaner()
        def node = cleaner.clean(address.toURL())

        // Convert from HTML to XML
        def props = cleaner.getProperties()
        def serializer = new SimpleXmlSerializer(props)
        def xml = serializer.getXmlAsString(node)

        // Parse the XML into a document we can work with
        def page = new XmlSlurper(false,false).parseText(xml)

        // Retrieve the logo URL
        properties["logo"] = page.body.div[0].div[1].div[0].div[0].div[0].img.@src
        </groovy>
    </target>

    <target name="print" depends="parse">
        <echo>
        Logo URL: ${logo}
        </echo>
    </target>

</project>

The parsing logic is pure groovy programming. I love the way you can easily walk the page’s DOM tree:

// Retrieve the logo URL
properties["logo"] = page.body.div[0].div[1].div[0].div[0].div[0].img.@src

ivy.xml

Ivy is similar to Maven. It manages your dependencies on 3rd party software. Here it’s being used to pull down groovy and the HTMLCleaner library the groovy logic is using:

<ivy-module version="2.0">
    <info organisation="org.myspotontheweb" module="demo"/>
    <configurations defaultconfmapping="build->default">
        <conf name="build" description="ANT tasks"/>
    </configurations>
    <dependencies>
        <dependency org="org.codehaus.groovy" name="groovy-all" rev="1.8.2"/>
        <dependency org="net.sourceforge.htmlcleaner" name="htmlcleaner" rev="2.2"/>
    </dependencies>
</ivy-module>

How to install ivy

Ivy is a standard ANT plugin. Download it’s jar and place it in one of the following directories:

$HOME/.ant/lib
$ANT_HOME/lib

I don’t know why the ANT project doesn’t ship with ivy.