Get Content Type of Request

Question

To find the incoming content type, docs say:

 request.headers["Content-Type"] # => "text/plain"

But I found by trial-and-error, that doesn't work, but this does:

 request.headers["CONTENT_TYPE"]=='application/json'

So what's the most robust+portable way to do it?

What version of rails are you working with ? – Intrepidd Mar 05 '13 at 15:22 — Intrepidd, Mar 05 '13 at 15:22
Judging by the tags he attached, probably 3.1 – DRobinson Mar 05 '13 at 15:34 — DRobinson, Mar 05 '13 at 15:34

score 44 · Accepted Answer · edited May 23 '17 at 11:47

44

I would usually go for request.format and request.content_type for reading these header fields.

EDIT: found a bit more on this that might help: https://stackoverflow.com/a/1595453/624590

edited May 23 '17 at 11:47

Community

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answered Mar 05 '13 at 15:14

DRobinson

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#binding.pry respond_to do |format| if (request.content_type == "application/json") format.json {render json: @user} elsif (request.content_type == "application/xml") format.xml {render xml: @user} else format.html end end – Aug 01 '17 at 18:25

score 26 · Answer 2 · edited Mar 22 '17 at 18:48

26

You don't need to parse the content_type string, Rails has already done this for you. Just check:

request.format.symbol == :json

edited Mar 22 '17 at 18:48

montrealmike

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answered Sep 29 '14 at 21:17

Kent Mewhort

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score 23 · Answer 3 · answered Mar 22 '17 at 18:47

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Another way of writing it:

request.format.json?

answered Mar 22 '17 at 18:47

montrealmike

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But if the request accept header is */*, it will still be false, right? – Nathan B Aug 08 '21 at 14:36

score 12 · Answer 4 · answered Nov 17 '15 at 23:06

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No need to call #symbol since equals is overloaded:

request.format == :json

answered Nov 17 '15 at 23:06

Tim Scott

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score 3 · Answer 5 · answered Feb 26 '14 at 11:59

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For me the best way to check if incoming request is a json was:

    if request.content_type =~ /json/

answered Feb 26 '14 at 11:59

Leszek

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score 2 · Answer 6 · answered Nov 15 '17 at 07:17

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request.format == 'application/json'

answered Nov 15 '17 at 07:17

amn

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score 1 · Answer 7 · answered Aug 25 '20 at 12:51

Seriously require focus to understand here. Ref. Rails 6.x with api only project

You have to make sure why you want request.content_type OR request.headers['Content-Type'] ? Explained below...

request.format OR request.headers['Accept'] is what format client is expecting to request's response by API(Service or Server).
request.content_type OR request.headers['Content-Type'] is what API(Service or Server) is expecting data format from request.

So if API(Service or Server) wants to request's data in application/json then you are right with request.content_type OR request.headers['Content-Type']

Get Content Type of Request

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