Boost Decidim With A New CreateDebate Mutation

by SLV Team 47 views
Boost Decidim with a New CreateDebate Mutation

Hey there, fellow Decidim enthusiasts! Are you ready to level up your platform with some fresh features? Today, we're diving deep into the world of Decidim mutations and crafting a brand-new one: the CreateDebate mutation. We'll walk through the process step-by-step, ensuring you have a solid understanding of how to implement it effectively. We'll be inspired by existing mutations, like the proposal_answer_type mutation, and draw parallels to controller actions. This guide will cover everything from file generation and spec creation to input schemes and example calls. Get ready to enhance your Decidim instance and create a more dynamic and engaging environment for your users. Let's get started, guys!

Unveiling the CreateDebate Mutation: A Deep Dive

Alright, let's get down to the nitty-gritty. Our goal is to create a CreateDebate mutation, which will be the backbone of allowing users to start new debates. Think of it as the engine that drives the creation process. This mutation will reside in the decidim-debates/lib/decidim/api/mutations/ folder, neatly organized alongside other critical API functionalities. We'll design this new mutation to align with the core principles of Decidim, ensuring it integrates smoothly into the platform's existing structure. Specifically, we'll draw inspiration from the proposal_answer_type mutation in decidim-proposals, treating it as our blueprint. This approach gives us a clear understanding of the design patterns we should follow. Also, we will use the CreateDebate command used in the debates controller. We are going to ensure that we understand how the parameters should be set to create this mutation.

To make this process as clear as possible, we will also follow a set of steps. First, we'll analyze the pull requests. This step is pivotal to understand the existing conventions and to know how to use them to match the project requirements. Second, we'll generate the required files, the specs, and the input schemes. The third is the complete example of how the mutation should be called. This includes the parameters, the request type, etc.

Analyzing Existing Decidim Pull Requests

Before we begin, it's essential to understand the context. We're going to study these pull requests (PRs) to understand how Decidim developers approach similar tasks, how they structure their code, and how they implement features within the Decidim ecosystem. By scrutinizing these PRs, we can identify patterns, best practices, and the overall style of the Decidim project. This insight is extremely useful when building our own mutation.

Here are the PRs we'll be looking at:

These pull requests provide us with a great insight into how similar features are implemented and the considerations that go into them.

Generating the CreateDebate Mutation Files

Now, let's roll up our sleeves and create the essential files needed for our CreateDebate mutation. We'll follow a structured approach to ensure everything is in order and easy to manage. We will be inspired by the proposal_answer_type, and the CreateDebate command to ensure that everything will work seamlessly. Let's look at the implementation step by step:

The Mutation File

We start with the core of our mutation. Create a new file, for example, decidim-debates/lib/decidim/api/mutations/create_debate.rb. This file will contain the logic for creating a new debate. We will be inspired by decidim-proposals/lib/decidim/api/mutations/proposal_answer_type.rb. The structure will be similar, containing the necessary arguments and the resolve method that handles the creation logic. The resolve method will interact with the CreateDebate command. We need to follow Decidim's conventions to ensure consistency throughout the platform.

# decidim-debates/lib/decidim/api/mutations/create_debate.rb
module Decidim
  module Api
    module Mutations
      class CreateDebate < BaseMutation
        argument :title, String, required: true, description: "The title of the debate."
        argument :description, String, required: false, description: "The description of the debate."
        # Add other arguments as needed, e.g., scope_id, category_id, etc.

        field :debate, Types::DebateType, null: true, description: "The created debate."
        field :errors, [String], null: false, description: "Any errors that occurred during the process."

        def resolve(title:, description: nil, **args)
          # Use CreateDebate command here
          command = Decidim::Debates::CreateDebate.new(context[:current_user], args.merge(title: title, description: description))
          if command.valid?
            result = command.call
            if result.success?
              { debate: result.debate, errors: [] }
            else
              { debate: nil, errors: command.errors.full_messages }
            end
          else
            { debate: nil, errors: command.errors.full_messages }
          end
        rescue => e
          { debate: nil, errors: [e.message] }
        end
      end
    end
  end
end

Input Schema

For structured input, we'll design an input schema, likely placed in decidim-debates/lib/decidim/api/types/create_debate_input_type.rb. This will define the structure of the data the mutation expects. The main reason is to validate the parameters that are sent by the client. This will ensure that all the parameters are correctly validated. Again, we can take a look at the proposal_answer_type mutation, and create a similar file.

# decidim-debates/lib/decidim/api/types/create_debate_input_type.rb
module Decidim
  module Api
    module Types
      class CreateDebateInputType < BaseInputObject
        argument :title, String, required: true, description: "The title of the debate."
        argument :description, String, required: false, description: "The description of the debate."
        # Add other arguments as needed
      end
    end
  end
end

The Spec Files

Specs are essential for ensuring our mutation works as expected. We will create test files in the decidim-debates/spec/api/mutations/create_debate_spec.rb directory. We will ensure that we write both system and unit tests. The most important is to ensure that the correct parameters are sent. The easiest way to get the specs is by looking at the existing ones. We will have to ensure that we are using the correct command. These tests will cover various scenarios. For example, successful debate creation, and handling validation errors.

# decidim-debates/spec/api/mutations/create_debate_spec.rb
require "spec_helper"

module Decidim::Api::Mutations
  describe CreateDebate do
    let(:user) { create(:user) }
    let(:organization) { create(:organization) }
    let(:current_component) { create(:component, organization: organization) }

    let(:mutation_context) { { current_user: user, current_component: current_component } }

    let(:mutation) { described_class.new(field: nil, context: mutation_context) }

    let(:title) { "My Awesome Debate" }
    let(:description) { "This is a debate about something cool." }

    it "creates a debate when valid parameters are provided" do
      command_double = double(Decidim::Debates::CreateDebate, call: double(success?: true, debate: create(:debate)), errors: [])
      allow(Decidim::Debates::CreateDebate).to receive(:new).and_return(command_double)

      result = mutation.resolve(title: title, description: description)

      expect(result[:debate]).to be_a(Decidim::Debates::Debate)
      expect(result[:errors]).to be_empty
    end

    it "returns errors when the command fails" do
      command_double = double(Decidim::Debates::CreateDebate, call: double(success?: false), errors: ["Title can't be blank"])
      allow(Decidim::Debates::CreateDebate).to receive(:new).and_return(command_double)

      result = mutation.resolve(title: "", description: description)

      expect(result[:debate]).to be_nil
      expect(result[:errors]).to eq(["Title can't be blank"])
    end

    # Add more tests for different scenarios, error handling, etc.
  end
end

Example: Calling the CreateDebate Mutation

Finally, let's explore how to call our newly crafted CreateDebate mutation. You will call this through a GraphQL request. Here's how a typical call might look:

mutation {
  createDebate(input: {
    title: "My New Debate",
    description: "Discuss the future of our city."
    # Add other input fields here
  }) {
    debate {
      id
      title
      description
    }
    errors
  }
}

This example showcases a GraphQL mutation. The createDebate field invokes our mutation, passing input arguments such as title and description. The response includes the created debate data (if successful) or a list of errors in case of any issues. This allows the front end to handle the response appropriately. Remember, the exact input parameters and response fields can be adjusted based on the specific needs of your Decidim instance.

Refining the Implementation: System Specs

System specs are crucial for testing the complete flow of our mutation. Let's create a system spec in decidim-debates/spec/system/user_creates_debate_spec.rb to simulate a user creating a debate. This will ensure that our mutation interacts correctly with the rest of the Decidim system. To develop the specifications correctly, you will have to follow the example provided in decidim-debates/spec/system/user_creates_debate_spec.rb.

# decidim-debates/spec/system/user_creates_debate_spec.rb
require "spec_helper"

describe "User creates a debate" do
  let(:user) { create(:user, :admin) }
  let(:organization) { create(:organization) }
  let!(:component) { create(:component, organization: organization) }

  before do
    login_as user, scope: :user
    visit decidim.new_debate_path(component)
  end

  context "when filling the form correctly" do
    it "creates a debate" do
      fill_in "debate_title", with: "My Awesome Debate"
      fill_in "debate_description", with: "This is a description of the debate."
      click_button "Create debate"
      expect(page).to have_content "Debate created successfully."
    end
  end
end

Wrapping Up and Next Steps

Congratulations, guys! We've successfully created the basic structure of the CreateDebate mutation. We've laid the groundwork for a more dynamic and interactive Decidim platform. Remember to thoroughly test your implementation and iterate on your design as needed. Now, it's time to create a draft PR in the decidim repository.

This is just the beginning. The next steps include adding more complex logic, incorporating error handling, and making sure the mutation aligns with the Decidim project's coding standards. Also, you will have to make sure that the integration with the front end is correctly. Consider using the existing mutation and use it to model your own.

Thanks for joining me on this journey, and happy coding! Don't hesitate to reach out if you have any questions or need further assistance. Good luck, and have fun creating debates!