Custom validator with arguments

[galaczi]

I would like to add a custom rule to filter out bad words from an input. It would take an array of strings just like the notIn rule. The documentation shows an example where no argument is needed. It is not clear what is the options objects since it does not contain the arguments I pass in a rule. How would I get those arguments inside the validator.rule() callback?

[galaczi]

I had to dig into the source code a bit to find that the second argument in the callback function should be compiledOptions. This is what I came up with:

validator.rule('doesNotContain', (value: string, compiledOptions: string[][], options) => {
  const found = compiledOptions.find((option) => value.includes(option))

  if (found) {
    options.errorReporter.report(
      options.pointer,
      'doesNotContain',
      `${found} is not allowed`,
      options.arrayExpressionPointer
    )
  }

  return
})

I still have questions.

1. What are the pointers in the options object?
2. Can I somehow return the found variable so I can access it for custom validation messages?
3. If I return out of the function does that mean the validation passed?

[tomgobich]

I'm a bit confused why you're not just using the notIn rule? It looks like you're pretty much just recreating it under a different name.

Also, it sounds like the below is the portion of the documentation you were looking for. It shows how to pass arguments into a custom validation rule and it shows how to use your custom rule's error properties to provide a custom message.
https://docs.adonisjs.com/guides/validator/custom-rules#passing-options-to-the-rule

You can also find more information about the error reporting system and what pointers are here:
https://docs.adonisjs.com/guides/validator/error-reporters#creating-your-error-reporter

The validation is passed if no errors are reported using the errorReporter and if no exceptions are thrown. Returning merely stop execution of further code within your rule.

[galaczi]

notIn validates the value to ensure it is not inside an array of provided values. However I am doing the opposite. Validate that the value (from a textarea) does not contain any of the array items (passed in to the rule).

Thanks for the additional explanation and the links! I don't know how I missed that part.

[tomgobich]

Oh, gotcha! That makes sense then, lol sorry.

Anytime!