Introduction to Chrome extension core concepts and the how-tos on building a Chrome extension which is 'parasitizing' on the host web application. Talk is supplemented with an example Chrome extension which adds functionality to Shift conference video stream.

1. Building web parasite
using
Chrome extension
Ivan Vukman
Senior Software Engineer at Pseudocode

2. What are Chrome extensions?
• Software programs
• Customize the browsing experience

3. What are Chrome extensions?
• Ranging from:

4. What are Chrome extensions?
• Ranging to:

5. Demo Web parasite extension

6. Demo Web parasite extension
• https://github.com/Vukman/WebParasite
• https://drive.google.com/file/d/1KezQhTj99ckZkE4a0eYFyeX_jFTuLPP
1/view?usp=sharing

7. Chrome extension concepts

8. manifest.json
• Describes the app
• It is the only required file
• Required name, version and
manifest_version keys

9. manifest.json
• Minimal (useless) extension

10. manifest.json
• Defines extension
permissions
• Defines which files are used
as extension components

11. Use your favorite libraries and tools
• Only output matters
• Used in demo extension:

12. Content scripts
• Files that run in the context of web pages
• Live in isolated world
• Defined in manifest:

13. Find stable mounting point for new element
• Demo content script:

14. Content script limitations
• Don’t have access to full chrome extension API
• Same origin policy as host (CORS, CORB)

15. Background script to the rescue!
• Runs in background and listens to events
• Encouraged to be non persistent (event driven)
• Has access to full Chrome extension API
• Can talk to remote servers outside of its origin

16. Communication between background and
content

17. Communication between background and
content

18. Browser action
• Gives visual identity
• Defines popup page

19. Popup page
• Privacy policy
• Context of active tab

20. Questions?
• ivan.vukman@pseudocode.agency