根据匹配的组使用属性值替换egexp

Question

我想用属性文件中的值替换css文件中的一些替换标记。到目前为止，我所做的是:

<target depends="prepare" name="build_css">
    <replaceregexp>
        <fileset refid="temp_css_files"/>
        <regexp pattern="{(.*)}"/>
        <substitution expression="${testprop}"/>
    </replaceregexp>
</target>

，它将成功地用testprop属性的值替换匹配的字符串。但是我想做的是，用一个名称为匹配字符串的属性来替换匹配的字符串。

因此，替换标记{myprop}将被属性myprop的值所替换。

我试着:

<target depends="prepare" name="build_css">
    <replaceregexp>
        <fileset refid="temp_css_files"/>
        <regexp pattern="{(.*)}"/>
        <substitution expression="${1}"/>
    </replaceregexp>
</target>

没有成功，因为匹配的字符串随后被字符串${myprop}替换。

这是可能的吗?或者有更简单的方法来完成我错过的另一项任务?

Answer 1

如果您可以使用典型的Ant ${...}语法来表示CSS文件中的属性，那么Ant的<expandproperties> FilterReader可能很有用:

<project name="ant-replace-tokens-with-copy-task" default="run">
    <target name="run">
        <property name="src-root" location="src"/>
        <fileset id="temp_css_files" dir="${src-root}">
            <include name="**/*.css"/>
        </fileset>
        <!-- The <copy> task cannot "self-copy" files. So, for each -->
        <!-- matched file we'll have <copy> read the file, replace the -->
        <!-- tokens, and write the result to a temporary file. Then, we'll -->
        <!-- use the <move> task to replace the original files with the -->
        <!-- modified files. -->
        <property name="filtered-file.extension" value="*.filtered-file"/>
        <copy todir="${src-root}">
            <fileset refid="temp_css_files"/>
            <globmapper from="*" to="${filtered-file.extension}"/>
            <filterchain>
                <expandproperties/>
            </filterchain>
        </copy>
        <move todir="${src-root}">
            <fileset dir="${src-root}" includes="**"/>
            <globmapper from="${filtered-file.extension}" to="*"/>
        </move>
    </target>
</project>

如果您需要坚持使用{...}语法，ReplaceTokens FilterReader将令牌替换为属性文件中定义的属性:

<project name="ant-replace-tokens-with-copy-task" default="run">
    <target name="run">
        <property name="src-root" location="src"/>
        <fileset id="temp_css_files" dir="${src-root}">
            <include name="**/*.css"/>
        </fileset>
        <!-- The <copy> task cannot "self-copy" files. So, for each -->
        <!-- matched file we'll have <copy> read the file, replace the -->
        <!-- tokens, and write the result to a temporary file. Then, we'll -->
        <!-- use the <move> task to replace the original files with the -->
        <!-- modified files. -->
        <property name="filtered-file.extension" value="*.filtered-file"/>
        <copy todir="${src-root}">
            <fileset refid="temp_css_files"/>
            <globmapper from="*" to="${filtered-file.extension}"/>
            <filterchain>
                <filterreader classname="org.apache.tools.ant.filters.ReplaceTokens">
                    <param type="tokenchar" name="begintoken" value="{"/>
                    <param type="tokenchar" name="endtoken" value="}"/>
                    <param type="propertiesfile" value="dev.properties"/>
                </filterreader>
            </filterchain>
        </copy>
        <move todir="${src-root}">
            <fileset dir="${src-root}" includes="**"/>
            <globmapper from="${filtered-file.extension}" to="*"/>
        </move>
    </target>
</project>