I have discovered a lot of problems in my mosaic / theme fragments templates.
I am not sure if they also were present in 5.2.1, but I am sure they are not there in 5.1.x
1. A lot of places I now need to encode, something like this:
def folder_url(self):
url = self.data['folder_url'].encode('ascii','ignore')
return url
This typically happens when (text) contains the character '-' (so 'images-folder' would break, but 'images_folder' would not break)
2. I can not use 'variables in style in templates, they need to be changed to 'pyton'
So (inside some_template.pt)
<style>
#fragment-${view/id} { color:blue; }
</style>
Does not work anymore, but you can change it to
<style>
#fragment-${python: view.id} { color:blue; }
</style>
UPDATE: as a curiosity I can tell that the same syntax inside a <script>-tag does NOT break / give error