Changes in XML templates breaks existing pages

[afroewis]

Q	A
Bug?	yes
New Feature?	no
Sulu Version	1.1.10

Actual Behavior

This issue is about changing a page's structure.

When you change the content type of a property in an existing template, you can't change that property in the actual page.

Example:

The property example has the content type text_line. Let's say you have a page that uses this template. If you change the content type of example to snippet (or likely any other content type), you can't change the example property in the admin interface and a JavaScript Error appears in the browser console.

Expected Behavior

The content editor should be able to change the example property after changing it's content type in the template's xml definition.

Steps to Reproduce

1. Create a page using SULU's built-in default.xml template (https://github.com/sulu/sulu-standard/blob/develop/app/Resources/pages/default.xml.dist)
2. Change the content type of the images property to contact
3. Edit the page you created in step 1. You're not able to change the images property.

[danrot]

Somehow related to one of our oldest issues: sulu/sulu#46

I am not really sure how to handle this...