You can edit a schema file from within the Developer tool to update schema components.
Edit a schema file in the Developer tool to make minor updates to a small number of files. For example, you might make one of the following minor updates to a schema file:
Change the minOccurs or maxOccurs attributes for an element.
Add an attribute to a complex type.
Change a simple object type.
When you edit a schema file, the Developer tool opens a temporary copy of the schema file in an editor. You can edit schema files with the system editor that you use for .xsd files, or you can select another editor. You can also set the Developer tool default editor for .xsd files. Save the temporary schema file after you edit it.
The Developer tool validates the temporary file before it updates the schema object. If the schema file contains errors or contains components that conflict with other schema files in the schema object, the Developer tool does not import the file.
When you edit and save the temporary schema file, the Developer tool does not update the schema file that appears in the
list. If you synchronize a schema object after you edit a schema file in the Developer tool, the synchronization operation overwrites your edits.