Transforming Rails 6 Params: From Flat Structure to Nested Hash of Hashes

Описание: Learn how to change your Rails 6 parameters from a flat structure into a well-organized hash of hashes, simplifying data handling in your application.
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This video is based on the question https://stackoverflow.com/q/67074895/ asked by the user 'mr_muscle' ( https://stackoverflow.com/u/10443890/ ) and on the answer https://stackoverflow.com/a/67076603/ provided by the user 'Sylvain FARNAULT' ( https://stackoverflow.com/u/13090717/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Transforming Rails 6 Params: From Flat Structure to Nested Hash of Hashes

In the world of web development, handling user input efficiently is a key aspect of creating a smooth user experience. If you're developing an application with Ruby on Rails and dealing with forms, you might find yourself needing to change the way parameters are structured when users submit their data. This guide delves into a specific problem in Rails 6: how to convert parameters from a flat hash to a more manageable hash of hashes. We'll break down the solution step by step, focusing on the specific case of survey data.

The Problem

Imagine you have a Rails application where users fill out a survey. This survey collects various answers tied to specific questions, and these responses need to be stored in the TestResult model. Currently, the parameters coming from your form might look something like this:

[[See Video to Reveal this Text or Code Snippet]]

However, for better organization and ease of use, you'd prefer the parameters to be structured as follows:

[[See Video to Reveal this Text or Code Snippet]]

This format not only makes it clearer which answer corresponds to which question but also makes your data handling much more intuitive.

The Solution

The good news is that you can change this structure in your Rails view. Below, you'll find a detailed explanation of how to create the necessary input fields in your form, ensuring that submitted parameters yield the desired nested hash structure.

Step 1: Update Your Form

In your view file, new.html.erb, you should modify the form to include hidden fields for questions and properly set names for both your question and answer inputs. Replace your form code with the following:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Understand the Parameter Structure

With this implementation, when the form is submitted, the parameters will now look like this:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Handle the Parameters in Your Controller

In your TestResultsController, make sure that the parameters are being permitted correctly. Your test_result_params method will remain as below:

[[See Video to Reveal this Text or Code Snippet]]

This ensures all nested parameters are permitted, allowing your application to safely handle the incoming data.

Step 4: Store the Data

When you create a new TestResult, the parameter structure now allows you to easily access the answers and corresponding questions. By using serialization, you can store this data cleanly in your model:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

By following these steps, you can transform your Rails 6 parameters from a simple hash into a nested hash of hashes. This structured approach not only simplifies your data handling but also enhances the overall maintainability of your code. If you face any issues with this setup or have suggestions, feel free to share!

With the right approach, handling user inputs in your Rails application can be both effective and elegant.