## Source page

In addition to the GUI pages, PDE provides a source page, where users who prefer to edit the plugin.xml file by hand, can work.

Since manual editing of the file can open the door to a wide variety of errors, both syntactic and semantic, PDE validates the file upon saving or switching tabs to flag such errors.

If a syntax error is introduced, PDE will lock out the form pages until the error is fixed. If you try to switch to any of the non-source pages, you will see the following dialog:

If you close the editor with syntactic errors in it and open it again, the editor will open into the Source page and other pages will not be accessible until the source is fixed.

The semantic errors, which PDE is able to detect, are listed on the Plug-ins tab of the Plug-in Development > Compilers preference page:

You can set the level of each to one of Error, Warning or Ignore.

Note that for PDE to be able to detect some of these problems (e.g. required attributes not defined, undefined extension attributes, etc.), extension points you are using must have a valid schema associated with them. See Extension Point Schema for more details.