I want to get some specific value from string of Rails like below these are two string.
1. "http://localhost:3000/admin/shops/assign_shoes?id=50&page=1"
2. "http://localhost:3000/admin/shops/assign_shoes?id=50"
I always need value of "id" which is "50". Don't matter how many parameters are in string
as query string.
Actually these strings are values of request.referer
Any efficient method?
Thanks
Here is one of the ways:
require 'uri'
require 'cgi'
uri = URI.parse("http://localhost:3000/admin/shops/assign_shoes?id=50&page=1")
# => #<URI::HTTP:0x000001018dc5c8 URL:http://localhost:3000/admin/shops/assign_shoes?id=50&page=1>
uri_params = CGI.parse(uri.query)
# => {"id"=>["50"], "page"=>["1"]}
uri_params["id"].first #=> "50" - NOTE: this will be a String!!
However, I'd prefer the answer which uses regular expressions.
require 'cgi' in rails, which is what the OP appears to be using. It seems the module is already included, I believe.
uri and cgi. :/Use regular expressions.
id = /\/admin\/shops\/assign_shoes\?id=(\d+)/.match(request.referer)[1]
Rack::Utils), and the regular expression will be more brittle. For example, you don't really care about the path, but if you change it, your regular expression will break. It will also be difficult to make a regular expression that accepts the id parameter at any position.
There are several different ways to do this, the common way I know about is parsing the string using the URI class, and making use of the CGI class to extract the query params, like so:
uri = URI.parse(request.referer)
parsed_query = CGI::parse(uri.query).symbolize_keys
id_value = parsed_query[:id].first
Note the .first, as the values of the query params are resolved to arrays. Additionally, the keys are parsed in to strings, therefore I would include symbolize_keys for convenience and consistency.
