Can you declare and use a variable inside an XML without using XSL to transform/parse the XML

Question

Say you have an XML element you want to read in an app, however you have multiple environments where the path of dependent files may change

<root>
  <element ID="MyConfigFile" url="c:\Program Files\MyProgram\resources\MyProgramconfig.xml" />
  <element ID="Executable" url="c:\Program Files\MyProgram\Prog.exe" />
</root>

...so you would want to make a reference to the relative directory

@path="c:\Program Files\MyProgram\"

<root>
  <element ID="MyConfigFile" url="@path\resources\MyProgramconfig.xml" />
  <element ID="Executable" url="@path\Prog.exe" />
</root>

Can you use a variable declared in the XML itself to reference the relative directory path?

Answer 1

You would need to add a DOCTYPE declaration to your file, declare an entity there and then reference that entity in the document body.

<!DOCTYPE root [
  <!ENTITY path "c:\Program Files\MyProgram">
]>
<root>
  <element ID="MyConfigFile" url="&path;\resources\MyProgramconfig.xml" />
  <element ID="Executable" url="&path;\Prog.exe" />
</root>