[Django] #35631: Include quality value when parsing Accept header

[Django]

#35631: Include quality value when parsing Accept header
-----------------------------------------+-----------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-----------------------------------------+-----------------------------
Requests have an `accepts` method for identifying the mimetype the user
can receive. However, when multiple formats are provided, a
[https://developer.mozilla.org/en-US/docs/Glossary/Quality_values "quality
value"] can be added to show the preferences on format. Handling this
value currently needs to be done by hand.

I propose:

1. Documenting the existence of `Request.accepted_types`
2. Extract the quality value, and store it as `MediaType.quality`
3. Sort `Request.accepted_types` by quality value

It would be nice to have an API to answer "I can return these mime types,
which would you prefer?", which I guess could be handled manually for now.
--
Ticket URL: <https://code.djangoproject.com/ticket/35631>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

[Django]

#35631: Include quality value when parsing Accept header

-------------------------------+---------------------------------------

Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0

Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

-------------------------------+---------------------------------------
Changes (by Carlton Gibson):

* stage: Unreviewed => Accepted

Comment:

I think step 3 should read "Sort Request.accepted_types by quality value
and specificity", e.g. `text/*;q=0.8,text/html;q=0.8` should be sorted
`text/html` first.

This is probably a sensible proposal. I suspect most people are not
sending the quality value, so `1` is assumed and it has no effect.
Nonetheless why not allow it?

We'd need a new helper API on HttpRequest taking a set of mime types to
match against, since the specificity question (`text/*`) makes it slightly
more complex than just returning the first match in accepted_types from
the set.

DRF has implementations of this logic that can be used for reference:

* [https://github.com/encode/django-rest-
framework/blob/8e304e1adbb0f99f91a15ed3abd379104bba3b89/rest_framework/negotiation.py#L53-L76
rest_framework/negotiation.py#L53-L76]
* [https://github.com/encode/django-rest-
framework/blob/8e304e1adbb0f99f91a15ed3abd379104bba3b89/rest_framework/utils/mediatypes.py#L27-L81
rest_framework/utils/mediatypes.py#L27-L81]
--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:1>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------+---------------------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted

Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------+---------------------------------------

Changes (by Jake Howard):

* has_patch: 0 => 1

Comment:

I've implemented the core of this feature here:
[https://github.com/django/django/pull/35631 PR], sans docs.

I'd appreciate a review, particularly around what API surface to expose.
--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:2>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------+---------------------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------+---------------------------------------

Comment (by Jake Howard):

[https://github.com/django/django/pull/18415 PR] now contains docs -
review away!
--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:3>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------+---------------------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 1

Easy pickings: 0 | UI/UX: 0
-------------------------------+---------------------------------------

Changes (by Sarah Boyce):

* needs_better_patch: 0 => 1

--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:4>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------+---------------------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0

Easy pickings: 0 | UI/UX: 0
-------------------------------+---------------------------------------

Changes (by Jake Howard):

* needs_better_patch: 1 => 0

--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:5>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------+---------------------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 1

Easy pickings: 0 | UI/UX: 0
-------------------------------+---------------------------------------

Changes (by Sarah Boyce):

* needs_better_patch: 0 => 1

--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:6>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------+---------------------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0

Easy pickings: 0 | UI/UX: 0
-------------------------------+---------------------------------------

Changes (by Jake Howard):

* needs_better_patch: 1 => 0

--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:7>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------+---------------------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 1

Easy pickings: 0 | UI/UX: 0
-------------------------------+---------------------------------------

Changes (by Sarah Boyce):

* needs_better_patch: 0 => 1

--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:8>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------+---------------------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0

Easy pickings: 0 | UI/UX: 0
-------------------------------+---------------------------------------

Changes (by Jake Howard):

* needs_better_patch: 1 => 0

--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:9>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------+---------------------------------------
Reporter: Jake Howard | Owner: Jake Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 1

Easy pickings: 0 | UI/UX: 0
-------------------------------+---------------------------------------

Changes (by Sarah Boyce):

* needs_better_patch: 0 => 1

--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:10>

[Django]

#35631: Include quality value when parsing Accept header

-------------------------------------+-------------------------------------

Reporter: Jake Howard | Owner: Jake
| Howard
Type: New feature | Status: assigned
Component: HTTP handling | Version: 5.0
Severity: Normal | Resolution:

Keywords: | Triage Stage: Ready for
| checkin

Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0

Easy pickings: 0 | UI/UX: 0

-------------------------------------+-------------------------------------
Changes (by Sarah Boyce):

* needs_better_patch: 1 => 0
* stage: Accepted => Ready for checkin

--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:11>

[Django]

#35631: Include quality value when parsing Accept header
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jake
| Howard

Type: New feature | Status: closed

Component: HTTP handling | Version: 5.0

Severity: Normal | Resolution: fixed

Keywords: | Triage Stage: Ready for
| checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Sarah Boyce <42296566+sarahboyce@…>):

* resolution: => fixed
* status: assigned => closed

Comment:

In [changeset:"e161bd4657177f0e723a14a6e414884363b31a5d" e161bd46]:
{{{#!CommitTicketReference repository=""
revision="e161bd4657177f0e723a14a6e414884363b31a5d"
Fixed #35631 -- Added HttpRequest.get_preferred_type().
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/35631#comment:12>