Stimulus File Input Validator

A Stimulus controller that allows you to run client side validations for files size and extension. This is an usefull aproachment for complement server side validations.

Installation

  yarn add stimulus-file-input-validator

Register the controller in your application

  import { Application } from '@hotwired/stimulus'
  import FileInputValidator from 'stimulus-file-input-validator'

  const application = Application.start()
  application.register("file-input-validator", FileInputValidator)

Usage

Define the following data:

• Add data-controller="file-input-validator"
• Add data-file-input-validator-max-file-size-value to load max file size allowed value in MB.
• Add data-file-input-validator-valid-extensions-value to load an array of allowed file extensions.
• Add an empty <div></div> with data-file-input-validator-target="errorMessage" target. Error messages will be loaded inside.
• Add a <template></template> with data-file-input-validator-target="errorTemplate" target and ERROR_MESSAGE. The template is going to be loaded into the error messages target div. This approach allows you to customize the design and keep the code clean.

  <form data-controller="file-input-validator"
    data-file-input-validator-max-file-size-value="20"
    data-file-input-validator-valid-extensions-value='["jpg", "png"]'>
    
    <label for="file-input" class="form-label">Load a file</label>

    <input type="file" data-file-input-validator-target="fileInput" data-action="change->file-input-validator#validate">

    <div class="form-text" data-file-input-validator-target="errorMessage"></div>

    <template data-file-input-validator-target="errorTemplate">
      <div class="alert alert-danger">
        ERROR_MESSAGE
      </div>
    </template>

    <button type="submit" class="btn btn-primary">Submit</button>
  </form>

Custom messages

You can customize error messages by setting data-file-input-validator-max-file-exceeded-error-message-value and data-file-input-validator-invalid-extension-error-message-value.

  <form data-controller="file-input-validator"
    data-file-input-validator-max-file-size-value="20"
    data-file-input-validator-valid-extensions-value='["jpg", "png"]'
    data-file-input-validator-max-file-exceeded-error-message-value="Wrong file size"
    data-file-input-validator-invalid-extension-error-message-value="Invalid extension"
    >

If no custom error messages are set the controller will use the default values.

Support for multiple files validations

You can use multiple html attribute to apply the validations values to multiple files.

  <input type="file" multiple id="myfile" name="myfile" data-file-input-validator-target="fileInput" data-action="change->file-input-validator#validate">

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/martinnicolas/stimulus-file-input-validator.

License

The package is available as open source under the terms of the MIT License.