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Your LimeSurvey version: 5
Own server or LimeSurvey hosting: not yet hosted
Survey theme/template: default
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hello LS community, i would like some tips / info, on how the system works, its components, dependencies, client side and server side.
sort of a dev guide if available, to get familiar with the software and being able to extend it without the worry to break something, or better, knowing what i will break whit the change i make.

i'm planning on forking the project and extend some of it's functionalities, so tips on local development are welcome (building, testing, debugging...) 
i'm not familiar with PHP development and derivate frameworks, so obvious things to other could not be for me. 
i tried to read the documentation, and the source code itself, but many things looks kinda obscure for someone who want to extend the system and it's just starting out.

i really appreciate your help, i will make other more specific question on related forum topics, see ya around, and happy hacking! 
 

hello LS community, i would like some tips / info, on how the system works, its components, dependencies, client side and server side.sort of a dev guide if available, to get familiar with the software and being able to extend it without the worry to break something, or better, knowing what i will break whit the change i make.

Nothing exist

i'm planning on forking the project and extend some of it's functionalities, so tips on local development are welcome (building, testing, debugging...) 

Why we help you to fork ?
And best is to start byb create plugins : you have a tutrial here : medium.com/@evently/creating-limesurvey-plugins-adcdf8d7e334 , and a lof of sample : manual.limesurvey.org/Available_third_party_plugins or manual.limesurvey.org/Category:Core_Plugins

i'm not familiar with PHP development and derivate frameworks, so obvious things to other could not be for me.  

?
I don't understand the whole point here …