Rails - Parameter with multiple values in the URL when consuming an API via Active Resource

Question

I am consuming an API that expects me to do requests in the following format:

?filter=value1&filter=value2

However, I am using Active Resource and when I specify the :params hash, I can't make the same parameter to appear twice in the URL, which I believe is correct. So I can't do this:

:params => {:consumer_id => self.id, :filter => "value1", :filter => "value2" }, because the second filter index of the hash will be ignored.

I know I can pass an array (which I believe is the correct way of doing it) like this:

:params => {:consumer_id => self.id, :filter => ["value1","value2"] }

Which will produce a URL like:

?filter[]=value1&filter[]=value2

Which to me seems ok, but the API is not accepting it. So my question are:

What is the correct way of passing parameters with multiple values? Is it language specific? Who decides this?

I'm a little confused. How can "filter" have 2 different values? — fatfrog, Mar 15 '12 at 03:52
Sorry what I mean is, it looks like the way the API is written, the filter value will just be overwritten by the last value passed. — fatfrog, Mar 15 '12 at 04:14
@fatfrog I don't know how the API is written, I am just fetching data according to their specs. But just so you know, the API is able to get the two values when their are passed like ?filter=value1&filter=value2 — Nobita, Mar 15 '12 at 04:29
Ok updated my answer- according to the docs, To send an array of values, append an empty pair of square brackets “[]” to the key name. — fatfrog, Mar 15 '12 at 04:34
@fatfrog You haven't written any answer. Also, read my question(s). Which docs do you refer to? — Nobita, Mar 15 '12 at 05:20

fatfrog · Answer 1 · 2012-03-15T04:30:56.017

8

http://guides.rubyonrails.org/action_controller_overview.html#hash-and-array-parameters

Try :filter[] => value, :filter[] => value2

edited Mar 15 '12 at 04:30

answered Mar 15 '12 at 04:13

fatfrog

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score 6 · Accepted Answer · answered Nov 13 '14 at 13:53

6

to create a valid query string, you can use

params = {a: 1, b: [1,2]}.to_query

http://apidock.com/rails/Hash/to_query
http://apidock.com/rails/Hash/to_param

answered Nov 13 '14 at 13:53

spr86

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score 1 · Answer 3 · answered Nov 25 '19 at 01:27

You can generate query strings containing repeated parameters by making a hash that allows duplicate keys. Because this relies on using object IDs as the hash key, you need to use strings instead of symbols, at least for the repeated keys.

(reference: Ruby Hash with duplicate keys?)

params = { consumer_id: 1 } # replace with self.id
params.compare_by_identity
params["filter"] = "value1"
params["filter"] = "value2"
params.to_query #=> "consumer_id=1&filter=value1&filter=value2"

Rails - Parameter with multiple values in the URL when consuming an API via Active Resource

3 Answers3

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