[CMS] get_pages_metadata should not ignore pages with no explicit metadata

[kvas]

Environment

CMS in static or dynamic mode.

How to reproduce

1. Create a page A that doesn't declare any metadata.
2. Create page B that uses get_pages_metadata global function to get the list of all pages and then outputs the list.

Observed behaviour

Page A is not in the list on page B.

Expected behaviour

Page A should be in the list.

References

• ​Code review of the original change (#4687).
• ​Discussion in another review.

[kvas]

@julian: in the original review, I understand your comment as that pages with no metadata should be present in the output of get_pages_metadata if no filters are given. Could you please confirm that this is still your preferences and that this change will not cause unintended side-effects in our existing websites that use get_pages_metadata? Thank you.

[juliandoucette]

@kvas I don't know what comment you are referring to. And I can't imagine wanting to use get_pages_metadata to retrieve a page with no meta data. e.g. In order to link to a page, I probably want a title or something for the link text.

I guess an intelligent default title could be the page name un-slugified and without the file extension. But I didn't request that.

[kvas]

@julian: It's ​your reply to my comment asking whether pages with no user-defined metadata should be filtered out or not. I understood it as you saying that the pages with no user-defined metadata should still be in the output, but I guess this is wrong.

This issue is rejected then.

[kvas]

I had a chat with @julian today and we've concluded that this ticket should be implemented even though the original request didn't go into these details:

6:38 PM <vasily> sorry to bug you about this again, but I think it would be useful to know how strong you feel about the choice in https://issues.adblockplus.org/ticket/6545. As I understand, the intention behind your initial request was that only pages with some user-defined metadata would be in the output of get_pages_metadata but how would you feel about all pages being there (you can filter them with explicit filters of course)?
6:38 PM <vasily> I'm asking because to me it seems that the a page appearing in the output after, for example, changing its template seems rather counterintuitive and potentially error-prone, so my preference would be to always include all pages that match filters (if any). But if you prefer it to stay the way it is, I would view it as a strong argument against changing things.
6:45 PM <julian> I agree with your preference.

Based on this I'm reopening this ticket.

[kvas]

Since the original request didn't specify the behavior that we want to achieve here, this ticket is not a defect but a change. I will keep the main text unchanged for simplicity.

[sebastian]

How wabout removing the filter functionality all together from get_pages_metadata()? There is much more powerful filter functionality already built into jinja.

Pages that have a given metadata key with a particular value:

get_pages_metadata()|selectattr('category', 'equalto', 'popular')

Pages that have a given metadata key with any of some values:

get_pages_metadata()|selectattr('category', 'in', ['popular', 'misc'])

Pages that have a given metadata key with any non-empty value (this isn't even supported by the current filter functionality get_pages_metadata() provides):

get_pages_metadata()|selectattr('title')

I prepared a ​patch to demonstrate how that would look like for help.eyeo.com. Its somewhat more verbose, but also more flexible, and it would make a bunch of code in the CMS obsolete.

What do you think, Julian?

[abpbot]

A commit referencing this issue has landed:
​Issue 6545 - Changes get_pages_metadata to return all pages