Parse JSON Into An OpenStruct

The json module that ships with Ruby is something I use a lot in web app APIs. When a request comes in as a string of JSON, I use JSON.parse to turn it into a hash. That's because a hash is much easier to work with than a string representation of some JSON data.

> require 'json'
=> true
> data = JSON.parse('{"name": "Josh", "city": "Chicago"}')
=> {"name"=>"Josh", "city"=>"Chicago"}
> data["name"]
=> "Josh"

The hash access syntax can sometimes get to be clunky. JSON.parse is flexible enough that it can do more than turn a JSON string into a hash. It can turn it into any object that plays along. OpenStruct is a great example of this.

To tell JSON.parse to use a class other than Hash, include the object_class option.

> json_str = '{"name": "Josh", "city": "Chicago"}'
=> "{\"name\": \"Josh\", \"city\": \"Chicago\"}"
> data = JSON.parse(json_str, object_class: OpenStruct)
=> #<OpenStruct name="Josh", city="Chicago">
> data.name
=> "Josh"

Because of how OpenStruct objects work, we can use method notation to access the fields parsed from the JSON string.

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