XML read/write is not idempotent

[Aliaksei-Tatarynchyk]

Shaper currently converts xml into yaml with errors, it doesn't able to distinguish child elements and attributes. E.g. if we have the following xml:

<rest-security>
  <default-acl value="Profile$login$restUser:read,write,execute"/>
  <default-acl2>Profile$login$restUser:read,write,execute</default-acl2>
  <default-acl3 value="test">Profile$login$restUser:read,write,execute</default-acl3>
  <default-acl4 value="test">
    <value>Profile$login$restUser:read,write,execute</value>
  </default-acl4>
</rest-security>

It will be converted to yaml:

  rest-security:
    default-acl:
      '@value': Profile$login$restUser:read,write,execute
    default-acl2: Profile$login$restUser:read,write,execute
    default-acl3:
      '@value': test
      '#text': Profile$login$restUser:read,write,execute
    default-acl4:
      '@value': test
      value: Profile$login$restUser:read,write,execute

Output xml after writing this yaml will be:

	<default-acl>
		<key name="@value">Profile$login$restUser:read,write,execute</key>
	</default-acl>
	<default-acl2>Profile$login$restUser:read,write,execute</default-acl2>
	<default-acl3>
		<key name="@value">test</key>
		<key name="#text">Profile$login$restUser:read,write,execute</key>
	</default-acl3>
	<default-acl4>
		<key name="@value">test</key>
		<value>Profile$login$restUser:read,write,execute</value>
	</default-acl4>
</rest-security>

It's drastically different. Also it ignores DTD declaration, e.g. if to put <!DOCTYPE rest-security SYSTEM "dynamosystemresource:/atg/dtds/rest/restSecurity_1.0.dtd"> it will not appear in yaml.

I'd suggest as quick fix - to change parser mapping for .xml files from XMLParser to TextParser. In this case the yaml will be:

test\xmtext.xml: |-
  <?xml version="1.0" encoding="UTF-8"?>
  <!DOCTYPE rest-security SYSTEM "dynamosystemresource:/atg/dtds/rest/restSecurity_1.0.dtd">

  <rest-security>
    <default-acl value="Profile$login$restUser:read,write,execute"/>
    <default-acl2>Profile$login$restUser:read,write,execute</default-acl2>
    <default-acl3 value="test">Profile$login$restUser:read,write,execute</default-acl3>
    <default-acl4 value="test">
      <value>Profile$login$restUser:read,write,execute</value>
    </default-acl4>
  </rest-security>

And the output xml will be identical to the initial one.