Another parameter you need to change is the html files:
Window-> Settings-> Web-> HTML Files-> Editor-> Indents Using Spaces
So, in short, these are the necessary steps:
- Window-> Settings-> General-> Editors-> Text Editors-> Insert Spaces for Tabs
- Window-> Settings-> Web-> HTML Files-> Editor-> Indent
- Window-> Preferences-> PHP-> Code Style-> Formatter and create a new profile
Here is a good post describing each step, hope this helps:
Zend Studio - insert spaces for tabs
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