Add order parameter

[vadimdemedes]

This PR adds order parameter to browse endpoints.

Closes #5602.

Supplied input string (e.g. title desc) is converted to the same format as produced by orderDefaultOptions():

{
    title: 'DESC'
}

Example

PostAPI.browse({ order: 'title desc, updated_at asc' });

Upper-cased DESC and ASC are also allowed. Spaces after commas are not required, this input is also valid: title desc, updated_at asc.

Note: If order parameter contains attributes, that do not belong to the current model, they will be ignored: bunny desc, title asc (bunny is skipped).

Todo

• test fields with dots in them, e.g. posts.title desc
• tests for other models (not sure this is needed)
• decide, if custom order option should completely overwrite or merge with default order options (orderDefaultOptions())

[sebgie]

looks good 👍, @ErisDS does ordering interfere with filtering?

[vadimdemedes]

Rebased latest changes, now ready to merge.

[ErisDS]

This doesn't interfere with filtering - it just needs to play nicely with it :) Using the model name prefix as mentioned here would help with that I think.

This is all looking great so far, it might be worth adding a test to show that you can order posts by author.name?

[vadimdemedes]

Sure, will update (it's in PR's todo list) ;)

[vadimdemedes]

So, while implementing support for ordering by rows from outside tables (when using join), I discovered an issue with the way Bookshelf fetches records (or how Ghost uses Bookshelf). It does not use join, but uses extra select query to fetch additional rows from other tables and then merges them into the final result.

For example, I want to fetch posts and include author information in them:

PostAPI.browse({include: 'author'});

I'd expect a select query with a join statement. But here's what happens instead:

It finds posts, then looks for author_id and finds that there are 3 unique author_ids. After that, it executes one more select with those ids. When that extra query is finished, author results get merged into posts result (into author column).

Summary: Because of this issue, it is not possible to order by "joined" values, e.g. author.name.

[vadimdemedes]

We are going to merge this PR as it is, without support for ordering by joined columns. Work on that problem will continue in a separate issue/PR (will be linked here).

[cobbspur]

Hey @vdemedes I have been trying to test this using the {{#get}} helper.

It is working nicely so far for posts but if I fetch users or tags then the ordering does not seem to be working.

Example

{{#get "tags" limit="8" page="1" order="slug asc" as |tags|}}
    {{#foreach tags}}
        <span>{{slug}}</span>
    {{/foreach}}
{{/get}}

Would you expect that to work/have I missed something?

[vadimdemedes]

Hey @cobbspur, that's my oversight, thanks for pointing this out!

[vadimdemedes]

@cobbspur I added ordering to Tag and User models ;) See #6019. I had to re-submit, because I removed my original fork.