Resolving EasyAdmin 4 Symfony 6 Dropdown Field Issues with Inheritance in Forms

Описание: Learn how to fix the dropdown issue in EasyAdmin 4 Symfony 6 where only one class type is displayed in inherited entities.
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This video is based on the question https://stackoverflow.com/q/76413327/ asked by the user 'MrDevel' ( https://stackoverflow.com/u/2235512/ ) and on the answer https://stackoverflow.com/a/76703691/ provided by the user 'MrDevel' ( https://stackoverflow.com/u/2235512/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Fix Dropdown Field Issues in EasyAdmin 4 with Symfony 6

When working with Symfony 6 and EasyAdmin 4, developers often face the challenge of displaying inherited entities correctly in dropdown fields. A common issue that arises is when the dropdown shows only one class type, while you may expect multiple entities to appear from an inheritance hierarchy. In this guide, we will explore a specific scenario where only Person entities are displayed and provide a clear solution to resolve the issue.

Understanding the Problem

The Class Structure

In our example, we start with an abstract base class called Applicant, which is an entity representing various types of applicants in the system. The class is defined as follows:

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

In this setup:

Inheritance Type is set to 'JOINED', which means that the Applicant class can have subclasses (Company and Person).

Discriminator Column is utilized to distinguish between these subclasses.

The Service Class

Now, the Service class references the Applicant class:

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

This relationship is crucial because it defines how Service entities will associate with Applicant entities.

The Issue

When rendering the form in the ServiceController, the dropdown for applicant only shows entities of type Person, but it should encompass both Person and Company. Here's the method in ServiceController that configures the fields:

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

The Solution

To resolve the issue of only having one class type displayed in the dropdown, you need to specify the correct options for the dropdown field in your configureFields method. This can be achieved by adding the form type options as follows:

Update Your Code

Replace your configureFields method with the following code snippet:

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

Breakdown of the Solution

setFormTypeOptions: This method allows you to specify additional options for the form field. In this case, we use it to set the class option to Applicant::class, enabling the dropdown to retrieve all entities that extend the Applicant class, including Company and Person.

Why the Change Matters: By explicitly defining the class in the options, we ensure that EasyAdmin can correctly pull and render all subclasses related to the Applicant entity.

Conclusion

By following the above approach, you should now see both Company and Person entities in your dropdown when creating or editing a Service. This not only enhances the user experience but also ensures data consistency across your application.

Now that you have this solution, you can apply it to similar scenarios where inheritance is used! Happy coding!