Modify Source Code in SAP Fiori MyLeads App (S4.view.xml)

Question

Hi Experts, 
I want to modify the Code of the standard SAP Fiori App "MyLeads" for some specific changes.    
Following structure of the app exists in Eclipse:    
I want to modify S3.view.xml and S4.view.xml (wich is the "Change" View of the Lead).  
S3.view.xml looks like:    
And S4.view.xml looks like: 
If I modify the Coding in S3, it works without a problem. I can create IconTabs and change the name of the text fields easily.    
After that, I´m trying to do this in the S4 View in the same way (only for text fields). But it doesn´t work anymore. I also want to change the field names and add or delete some fields, not more. 
I tried following things in S4 View:    
Change Text-Fields: 
Add new Titels in the i18n_de.properties (in my case DE) and replace them with the old Label-Titels in the code of S4.view.xml 
Overwrite the old Label-Titels in the code of S4.view.xml with simple static text 
Add / Delete Text Fields: 
comment the old text fields out 
delete the old text fields 
copy the old text fields and change them 
All of these things don´t work in S4. The code-changes aren´t visibile. It displays always the Standard Text Fields, however wich changes I tried to do.     
The only change that works was the change of the text of the standard Label-Titels in the i18n_de.properties, but this is not a good solution.    
While I work with the code, I see that the code relegates the field names (and also the items) from a JSON (for example: text= "{json>OriginText}").
My Questions after this long explanation:    
Why is it in S3 possible to change the code and in S4 not? (in the same way) Is there a reason why? 
Where should I modify the Code? In this mysterious JSON? In the S4.view.xml? In the i18n_de.properties?    
Is there a chance, to modify the app on a smart way?    
I´m new in this area, I hope you can help me a litte bit. I think my changes should be not to difficult.
Thanks!
Best Regards 
Tim    
Tags edited by: Michael Appleby

Answer 1

what's the value of this ? Does it denotes the app ? if yes, it should be this.to instead of this.nav.to.
Regards
Sakthivel