Here’s a quick post on how one can leverage the new mechanism of “Extending Spaces” to edit Spaces’ resources (like Page Templates) in JDeveloper.
Step 1: Make a copy of “WebCenter Spaces Side Navigation” and Download it from Spaces
Step 2: Open the workspace (DesignWebCenterSpaces.zip available here) and import the Page Template archive (.ear)
Step 3: Make a few changes a) drag and modify the width of the side “panel” b) add a panel customizable so we can add taskflows from the resource catalog
Step 4: Save and right-click on template and select “Upload Portal Resource”
Step 5: See the changes show up in Spaces instantly! Further edit template using composer.
Step 6: Add a spaces switcher or any other taskflow.
Save and you are done!