I am working on a Magento project and it is due an update; so I am wondering which folders will it replace/affect during an update. I am used to working with wordpress which leaves the entire ‘wp-content’ folder ( all the user data ) untouched during an update – I presume magento does something similar and doesnt overwrite custom theme files, media uploads (and hopefully not products and user data anyway) but then I read the following from this page which confuses me
For several of the first Magento themes I built, I copied the layout files from the default or blank theme into the custom theme layout folder. I would then modify the layout files directly, editing or commenting out content in files like: catalog.xml, page.xml, checkout.xml, etc… I never liked editing these files directly, as I knew that when it came time to upgrade to a newer version of Magento that had upgraded the layout files, I’d have to merge the changes into the new layout files.
I think I may just have a mistunderstanding specifically about layout files but all the same could someone clarify for me which locations (if any) that I might expect to loose data from during an update ( so that hopefully I can avoid using these locations )
You won’t loose any data if you have made your edits in custom theme package/folder and not in core code (but in tyour own extensions and code/local code-pool). However as you mentioned yourself it would be wise to merge your theme to be based on new layout files and same goes for template files as well
you can use a diff tool for that that can compare entire folder structures (winmerge, things and so on) and compare your theme and base theme folders
lets clarify things