CODEWITHSUNDEEP
ruby-on-railsrubycaching
David
David

Reputation: 241

Cache an http call results in rails

I am new to rails and get stuck on this problem.

The thing I am trying to do is: I need to call service A to retrieve an idA and then I use idA to perform other actions. my actions in the controller is something like

class SomeController < ApplicationController
  def someAction
    idA = getIdAfromServiceA(config)
    doSomethingElseToServiceB(idA)
  end
end

Since the result from serviceA only depends on config, once the config is loaded, idA should not change. Therefore I want to cache idA.

I tried to use instance variable to cache it, no luck("getIdAfromServiceA is called is printed" on every request)

class SomeController
  def getIdAfromServiceA(config)
    @IdA ||= getIdAfromServiceAviaHTTP(config)
  end

  private
  def getIdAfromServiceAviaHTTP(config)
     puts "getIdAfromServiceAviaHTTP is called"
     #make some http call
  end
end

I also tried to put it in application.rb to cache it on start up. it shows error: undefined method 'getIdAfromServiceAviaHTTP' for SomeHelper:Module (NoMethodError)

module MyProject
  class Application < Rails::Application
    config.load_defaults 5.1
    require_relative 'relativePathToSomeHelperModule'
    config.idA  = SomeHelper.getIdAfromServiceAviaHTTP(config)
  end
end

So my question is, what's a good way to achieve this ? I've been googling for a while but end up in vain. Could you help me with it ? Thanks !

Upvotes: 1

Views: 65

Answers (1)

Radix
Radix

Reputation: 2747

Create a ruby file in under /config/initializers/ and put that code there.

Option 1:

# config/initializers/ida_from_api.rb

IDA = SomeHelper.getIdAfromServiceAviaHTTP(config)

You can then use IDA through out the application.

Option 2:

# config/initializers/ida_from_api.rb

Rails.configuration.idA = SomeHelper.getIdAfromServiceA(config)

You can then use Rails.configuration.idA through out the application. Check Custom configuration for more details.

FYI - files under initializers loaded at the time of application startup.

Upvotes: 4

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