Feature: Azure PDF scan

[dinhtungdu]

Description of the Change

This PR utilizes the Azure Computer Vision Read API to extract text from multi-page PDF files. It supports both textbase and text-heavy image base pdf files.

Because of the Read API design, this feature uses WP Cron to periodically check and grab the result.

Verification Process

1. Go to ClassifAI > Image Processing.
2. See the new setting Enable Scanning PDF.
3. Enable that feature.
4. Upload a PDF file.
5. Right after the file is uploaded, open its media modal, see Classifai Read PDF field with a disabled In progress! button.
6. Wait for some minutes for API to process the file, check the modal again, see the description field filled with content of the PDF file.
7. Open the attachment detail page, see a new metabox Classifai PDF Processing with rescan checkbox.

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests passed.

Applicable Issues

Changelog Entry

[dkotter]

Haven't fully tested this out yet but code looks good. Left a few minor comments

[dinhtungdu]

@dkotter Thanks for the head up, I fixed those typo issues.

[phpbits]

@jeffpaul @dinhtungdu Confirming that this feature is working as expected. I followed the steps and the PDF file was scanned successfully. See screenshot below:

[helen]

Nice, it's working! We probably need to get smarter with the scan button in a future release, because you can do something like request a scan, switch items, come back, and request another scan. It should probably check the status any time that button is loaded up, or load the button with AJAX entirely.