Adds FieldIdentifier parameter to FluentValidationMessage

[thebarrettlo]

Pull Request

📖 Description

Adds a new parameter, Field (of type FieldIdentifier) to the FluentValidationMessage component. This allows validation messages to be specified with a direct reference to a field within an EditContext/EditForm, rather than only through an accessor.

For fields that represent a property on a pre-defined model passed to an EditContext, this parameter is extraneous since those model (auto-)properties double as a field accessor. However, for dynamic models that do not have design-time accessors, a FieldIdentifier is more reliable than an accessor.

Example usage

With some additional work, an EditForm can work with a dictionary rather than an object model:

<EditForm EditContext=@_editContext>
    @foreach (KeyValuePair<string, string?> kvp in _dynamicModel)
    {
        <FluentTextField Id=@kvp.Key
                         Label=@kvp.Key
                         Placeholder="Enter a string"
                         Value=@(_dynamicModel[kvp.Key])
                         ValueChanged=@(value => OnValueChanged(kvp.Key, value)) />
        <FluentValidationMessage Field=@(_editContext.Field(kvp.Key)) TValue=FieldIdentifier />
        @* <FluentValidationMessage For@(() => _dynamicModel[kvp.Key]) /> or something similar will not work *@
    }
</EditForm>

@code {
    private EditContext _editContext = new(new object());
    private Dictionary<string, string?> _dynamicModel = new();
    private ValidationMessageStore? _validationMessageStore;

    protected override void OnInitialized()
    {
        // Example model with a dictionary
        _dynamicModel = new()
        {
            { "Key 0", null },
            { "Key 1", null }
        };
        _editContext = new EditContext(_dynamicModel);
        _validationMessageStore = new ValidationMessageStore(_editContext);
    }

    private void OnValueChanged(string key, string value)
    {
        _dynamicModel[key] = value;

        // Validate the field here for example
        FieldIdentifier fieldIdentifier = _editContext.Field(key);
        _validationMessageStore?.Clear(fieldIdentifier);

        if (string.IsNullOrWhiteSpace(value))
        {
            _validationMessageStore?.Add(fieldIdentifier, "The field is required.");
        }
    }
}

No input given:

Valid input and invalid (white space) input:

(I don't have a fix for the "valid" border color showing even though the field is invalid. Suggestions very welcome 😃)

🎫 Issues

• feat: add direct FieldIdentifier parameter to FluentValidationMessage #1465

👩‍💻 Reviewer Notes

📑 Test Plan

No tests affected by this addition. This new property has been tested in a scenario such as above and more complex.

✅ Checklist

General

• I have added tests for my changes.
• I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation and followed the standards for this project.

Component-specific

• I have added a new component
• I have added Unit Tests for my new compontent
• I have modified an existing component
• I have validate Unit Tests for an existing component

⏭ Next Steps