docs: ADR introducing mobile offline content support #35011
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I suggest adding a comprehensive list of content types that will support offline viewing (maybe not all will be implemented at a time). |
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@GlugovGrGlib Just for curiosity how this ADR is different from this PR? |
Hello @angonz! I have updated the ADR and now there is a list of blocks that are planned to be supported. I also added a diagram to make it clearer how the content generation process will work. Please check it out. As for videos, video uploading is already implemented in mobile applications. |
Hi @salman2013, the functionality added in the PR you mentioned corresponds to what is described in this ADR. |
| * Figma | ||
| * Offline mode product pages |
| It was decided to include a fraction of Open edX xBlocks to be supported. | ||
| The following list of blocks is currently planned to be added to the support: |
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I'm glad you enumerated these. I agree that it makes sense to start with a subset of XBlocks.
I think it would be good to keep the door open for future XBlocks to be supported. Could you build this in a way that would allow that? For example, can we make sure that it is possible to add support for an external XBlock like xblock-drag-and-drop-v2, without adding knowledge of xblock-drag-and-drop-v2 to edx-platform?
Relatedly, please keep in mind that we are extracting all built-in edx-platform XBlocks into a separate repo. It will take some time, but the CAPA ProblemBlock will eventually be extracted as part of that project. So, when you implement this, it is important that we are not hard-coding more CAPA knowledge into the publishing process-- the CAPA-specific archiving code should stay within the ProblemBlock definition.
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Thank you for your question!
For offline content generation, we will use an html renderer very similar to the one used in the LMS, so there shouldn't be any significant issues with adding support for new blocks.
As for your question about xblock-drag-and-drop-v2 or other external XBlocks, yes, we won't need to add changes to the edx platform for each of them. I think that some refactoring/improvements will be needed in the future to expand the types of supported blocks, but it definitely shouldn't be for each new block separately.
As for CAPA, yes, the CAPA block will not be used.
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As for CAPA, yes, the CAPA block will not be used.
@NiedielnitsevIvan Can you clarify this statement? "CAPA" is just another name for the ProblemBlock, which implements most of the core problem types. To implement offline support for most problems, the app will need to download archives of CAPA problem data and render CAPA html/javascript.
….com:raccoongang/edx-platform into glugovgrglib/mobile_offline_availability_ADR
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| Extend mobile API endpoint for Course Home, to return information about offline content available for download for supported blocks |
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Please provide the exact URL
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| * **Implement of a mechanism for generating and storing on a server or external storage**: The course content should be pre-generated and saved to the storage for later download. | ||
| * **Render content**: Generate HTML content of block as it does for LMS. |
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What Python function will call in order to render the HTML?
Does that function require a user_id? If so, how will you handle that?
| * **Track course publishing events on CMS side**: Signal in the CMS that makes request to LMS to update course content. | ||
| * **Track course publishing events on LMS side**: API endpoint to receive the signal from CMS and update course content. |
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I can see that this would work, but I am curious if there is a more elegant approach. I have asked in #architecture.
| * **Sync Mechanism**: Periodically synchronize local data with the server when the device is online. | ||
| * **Sync on app side**: On course outline screen, check if the course content is up to date and update it if necessary. |
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Please say more about:
- How the offline app will respond when a user hits Submit
- What local state the app will store and in what format it will store it
- How the app will synchronize this state with the server
Description
This PR introduces an ADR outlining the approach to enable offline content support in the Open edX mobile application. The ADR documents the proposed solution, including content generation, API extensions, and synchronization mechanisms.
Key Decisions:
Offline Content Generation:
ZIP archives of xBlock content (HTML, assets, and assessments) will be pre-generated during course publishing and stored for mobile download.
Retries failed generation tasks with progressive delays.
Supports both local and S3 storage.
Mobile API:
Extends the Course Home API to include offline content availability (URL, size, last modified timestamp).
JavaScript Bridge:
Enables CAPA problem submissions via JSON messages through native mobile bridges.
Partial support for hints/feedback in problem types.
Supported xBlocks:
Includes common problem types (checkboxes, dropdown, text/numerical input), text/video blocks, and partial support for blocks with hints/feedback.
Consequences:
✅ Pros: Improved accessibility for learners with unreliable connectivity, increased engagement.
⚠️ Cons: Added complexity in content sync/storage, potential app size increase.
Rejected Solutions:
Supporting information
FC-0047