What is the problem?
If you enter an invalid OCR engine name, it returns a 500 error.
We should probably return a nice validation message, saying which engines we do support.
URLs to reproduce problem
Environment
Wikimedia OCR: Version 0.2.0
Description
Description
Related Objects
Related Objects
Event Timeline
Comment Actions
Yes! You found that by manually entering in an invalid engine, right? In other words, you didn't discover this through a normal user workflow?
Comment Actions
I actually got an email alert with this error, so I don't know how the user got to there.
Comment Actions
I actually got an email alert with this error, so I don't know how the user got to there.
I'm going to assume that was us, because there's no user-facing way to give an invalid engine without manipulating the URL.
I went in circles trying to get messaging to show about an invalid engine, but the way the system works now makes this very difficult because the view depends on there being a valid engine, and we can't show flash messages in the context where we're setting the engine. Additionally, if we throw an OcrException, it halts execution and other parameters such as the image URLs don't get set (which also depend on an engine being set).
Basically, while we definitely can show a message to the user, it requires a lot of hacky code that I felt just wasn't worth it. So for now, we silently fall back to the default engine (which I have set as google).
Pull request: https://github.com/wikimedia/wikimedia-ocr/pull/30
Comment Actions
@MusikAnimal Weird bug I cannot explain:
- Go to https://ocr-test.wmcloud.org/api.php?image=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F2%2F20%2FENC_9-0379.jpg&engine=foo
- Then go to https://ocr-test.wmcloud.org/?image=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F2%2F20%2FENC_9-0379.jpg&engine=google
The second request shows the error: The requested engine 'foo' was not found. Using the default engine 'google' instead. (but the OCR is successful).
In fact, if you submit the first link multiple times you get multiple instances of the error.
It also happens if you first go to https://ocr-test.wmcloud.org/api/available_langs?engine=foo.
It only happens if you use the same browser for both requests, so I guess something is cached on the browser-side.
Comment Actions
Nice find! That's the intended behaviour of flash messages in Symfony. Flash messages are stored as part of your session, and aren't removed until they are shown. So the solution here is to surface them in the API response (something we should be doing anyway). I'll submit a new PR for this.
Comment Actions
PR for exposing flash messages in API responses: https://github.com/wikimedia/wikimedia-ocr/pull/51
Comment Actions
We now show a nice error message (The requested engine 'foo' was not found. Using the default engine 'google' instead.) when passing an invalid engine to:
- Web UI https://ocr-test.wmcloud.org/?image=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F2%2F20%2FENC_9-0379.jpg&engine=foo
- API https://ocr-test.wmcloud.org/api.php?image=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F2%2F20%2FENC_9-0379.jpg&engine=foo
- The available_langs endpoint https://ocr-test.wmcloud.org/api/available_langs?engine=foo
Test environment: https://ocr-test.wmcloud.org Version 0.6.0-5-g81a7edc.