Handling errbacks #158
Merged
Handling errbacks #158
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The errback should never have been defaulted to the 'parse' method of the spider. By doing this it invalidates what the scrapy docs say. Also, there is no documentation on the scrapy site that says that exceptions get sent to the parse method. The reason this was found is because the error handling in the `process_spider_exception` middleware was never getting called as the scrapy docs said it should be. The workaround to get it to work the way it did before with the 'parse' method is add `&errback=parse` in the request.
This will allow the ability to change the non-standard behavior of sending exceptions to the `parse` method of the spider without introducing a breaking change to scrapyrt. It also introduces some documentation of the existing behavior.
Currently the application is not reporting to the user when the user provides an invalid errback or callback method. The scheduling of the request and validation of the spider callback and errback happens in a different thread than the one which is handling the api request. So, we need a different mechanism to communicate with the api request thread than simply raising the exception. We already do this for other errors and responses by adding properties to the CrawlManager object. So it seems best to also communicate this exception to the api request by using a user_error property on the CrawlManager. Then the exception can be raised in the context of the api request.
Co-authored-by: Adrián Chaves <[email protected]>
Co-authored-by: Adrián Chaves <[email protected]>
Gallaecio
approved these changes
Feb 14, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
No description provided.