I wanna add few stuff to qa_post_html_fields funtion in qa-app-format.php and already did it but woth core hack. How an I override it without touching the core, using layer or plugin?
Based on your comment, you just want to add the category title before the question title in question view and question lists. It is not necessary to override a 362-line function to do so.
Answer is a bit long so I'm exceeding the max answer length so I created this Gist: https://gist.github.com/pupi1985/ebeb18fae2d8cc9cf31f
You should modify your qa-theme.php accordingly.
Then just apply the CSS based on your category: span.qa-q-item-title-cat-44 applies to category id 44. A screenshot might help users who don't find it easy to follow code:
1\ In qa-plugin.php
qa_register_plugin_overrides('Your plugin php file').
In "your plugin php file," just override the function you want to change.
source:http://question2answer.org/overrides.php
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.