Pass parameters to validation

[Devqon]

I'm submitting a ... (check one with "x")

[ ] bug report => search github for a similar issue or PR before submitting
[x] feature request
[x] support request

Current behavior
There is not a pre-defined way to pass in parameters to the validators, other then using templateOptions or some other field. I tried a custom property on the validators object, but it is interpreted as validator on itself.

Expected behavior
There should be a way to pass parameters to a validator in a logical way.

Minimal reproduction of the problem with instructions
https://stackblitz.com/edit/angular-ngx-formly-cck62q

What is the motivation / use case for changing the behavior?
I want to do validation on dates for future and/or past validation.

Please tell us about your environment:
..

• Angular version: 2.0.X
  7.x

• Browser: [all | Chrome XX | Firefox XX | IE XX | Safari XX | Mobile Chrome XX | Android X.X Web Browser | iOS XX Safari | iOS XX UIWebView | iOS XX WKWebView ]
  all

• Language: [all | TypeScript X.X | ES6/7 | ES5]
  Typescript

[MantasJur]

I don't know whether this is a solution to your problem, but when I need extra parameters in my validators, I just make the validator itself a higher order function, taking in some parameters. For example, if I need access to the entire model in my validator I do:

export function SomeValidator(model: any) {
  return (control: AbstractControl) => {
    // do validation
  };
}

And for usage, it's just

validation: [SomeValidator(this.model)]

[Et3rnal]

@iMantasas I'm trying your approach but all I get is
There is no validator by the name of "dateMustBeAfterValidator(this.model)"
What did you have in FormlyModule.validators?
Could you please provide a Stackblitz ?

[scottux]

// Wrap your validator with an outer function to pass in the options parameter.
function FutureDateWithOptions(options) {
  return FormlyDateFutureValidator;

  function FormlyDateFutureValidator(c: AbstractControl, field: FormlyFieldConfig): ValidationErrors | null {
    if (!c.value) {
      return null;
    }
    // Use the options parameter if provided, or make a default one.
    options = options || { days: 2 };
// ...

Calling the function with the options object will return a FormlyDateFutureValidator using those options.

validators: [
    { name: 'date-future', validation: FutureDateWithOptions({days: 3}) },
 ]

This is not the cleanest way to do it, as you may want to do a merge of the options.

let defaults = { days: 2 };
// Use the options parameter if provided, or make a default one.
// Merge options with defaults instead of overwriting.
options = Object.assign({}, defaults, options}; 

[aitboudad]

This issue has been fixed and released as part of v5.7 release. Check our demo example https://formly.dev/examples/validation/custom-validation-parameters

Please let us know, in case you are still encountering a similar issue/problem.
Thank you!