Ant macrodef:有没有办法获取元素参数的内容? [英] Ant macrodef: Is there a way to get the contents of an element parameter?

问题描述

我正在尝试在Ant中调试macrodef.我似乎找不到一种方法来显示作为元素发送的参数的内容.

I'm trying to debug a macrodef in Ant. I cannot seem to find a way to display the contents of a parameter sent as an element.

<project name='debug.macrodef'>
  <macrodef name='def.to.debug'>
    <attribute name='attr' />
    <element name='elem' />
    <sequential>
      <echo>Sure, the attribute is easy to debug: @{attr}</echo>
      <echo>The element works only in restricted cases: <elem /> </echo>
      <!-- This works only if <elem /> doesn't contain anything but a
           textnode, if there were any elements in there echo would
           complain it doesn't understand them. -->
    </sequential>
  </macrodef>

  <target name='works'>
    <def.to.debug attr='contents of attribute'>
      <elem>contents of elem</elem>
    </def.to.debug>
  </target>

  <target name='does.not.work'>
    <def.to.debug attr='contents of attribute'>
      <elem><sub.elem>contents of sub.elem</sub.elem></elem>
    </def.to.debug>
  </target>
</project>

示例运行:

$ ant works
...
works:
 [echo] Sure, the attribute is easy to debug: contents of attribute
 [echo] The element works only in restricted cases:  contents of elem
...

$ ant does.not.work
...
does.not.work:
 [echo] Sure, the attribute is easy to debug: contents of attribute

BUILD FAILED
.../build.xml:21: The following error occurred while executing this line:
.../build.xml:7: echo doesn't support the nested "sub.elem" element.
...

所以我想我需要一种以某种方式将<elem />的内容转换为属性的方法(某些扩展的macrodef实现可能具有该属性)，或者我需要一种可以打印出任何XML树的<element-echo><elem /></element-echo>你放进去有人知道其中任何一种的实现吗?当然，欢迎使用任何第三种出乎意料的方式获取数据.

So I guess I need either a way to get the contents of the <elem /> into a property somehow (some extended macrodef implementation might have that), or I need a sort of <element-echo><elem /></element-echo> that could print out whatever XML tree you put inside. Does anyone know of an implementation of either of these? Any third, unanticipated way of getting the data out is of course also welcome.

推荐答案

echoxml 任务?

在您的示例构建文件中，替换行

In your example build file replacing the line

<echo>The element works only in restricted cases: <elem /> </echo>

使用

<echoxml><elem /></echoxml>

产生

$ ant does.not.work
...
does.not.work:
     [echo] Sure, the attribute is easy to debug: contents of attribute
<?xml version="1.0" encoding="UTF-8"?>
<sub.elem>contents of sub.elem</sub.elem>

但是也许不需要XML声明.您可以使用echoxml file属性将输出放置到一个临时文件中，然后读取该文件并删除声明，或者根据需要重新格式化信息.

Perhaps the XML declaration is not wanted though. You might use the echoxml file attribute to put the output to a temporary file, then read that file and remove the declaration, or reformat the information as you see fit.

编辑

在反射时，您可能会接近您所描述的内容，例如您的macrodef的连续主体

On reflection, you can probably get close to what you describe, for example this sequential body of your macrodef

<sequential>
  <echo>Sure, the attribute is easy to debug: @{attr}</echo>
  <echoxml file="macro_elem.xml"><elem /></echoxml>
  <loadfile property="elem" srcFile="macro_elem.xml">
    <filterchain>
      <LineContainsRegexp negate="yes">
      <regexp pattern=".xml version=.1.0. encoding=.UTF-8..." />
      </LineContainsRegexp>
    </filterchain>
  </loadfile>
  <echo message="${elem}" />
</sequential>

给予

$ ant does.not.work
...
does.not.work:
     [echo] Sure, the attribute is easy to debug: contents of attribute
     [echo] <sub.elem>contents of sub.elem</sub.elem>

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