Add guidance for styling invalid inputs

[Pixcell]

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This repository's issues are reserved for feature requests and bug reports.

• Do you want to request a feature or report a bug?
  Feature
• What is the current behavior?
  The only class available on md-input is .md-focused
• If the current behavior is a bug,
  please provide steps to reproduce and if possible a minimal demo of the problem
  via https://plnkr.co or similar.
• What is the expected behavior?
  It would be great if the classes of ngControl could be transfered to the md-input label and the md-input underline, in order to display live return on the validity of inputs
• What is the motivation / use case for changing the behavior?

Better User experience

• Which version of Angular and Material, and which browser and OS does this issue affect?
  Did this work in previous versions of Angular / Material?
  Please also test with the latest stable and snapshot versions.
• Other information
  (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix)

[cschroeter]

import {Directive, HostBinding} from '@angular/core';

@Directive({
    selector: '[input-error]'
})
export class InputErrorDirective {

    @HostBinding('attr.dividerColor')
    get isValid() {
         // Checks..
         return 'warn';
    }
}

The @HostBinding or better the setAttribute() function is not case-sensitive. This results in

<md-input [...] dividercolor="warn"></md-input> 

and unfortunately this don't work.

Any ideas?

[leocaseiro]

For the time being, I'm using a md-hint to show my error messages:

<md-input>
    <md-hint *ngIf="error" [ngStyle]="{'color': 'red'}" align="start">{{errorMessage}}</md-hint>
</md-input>

It might help someone

[csabattilas]

Is there a class we can use linked to theming?

[leocaseiro]

@krigton You can use the SASS md-color for theming,

.unicorn-carousel {
    color: md-color($warn);
}

see more on the guide

[csabattilas]

so no class already there for errors? we can put what we want?

[leocaseiro]

Hi @krigton, yep. My solution is temporary.

Hope works for you.

You can use any color from material or create your own.

update from md to mat

Example:

@import '~@angular/material/core/theming/all-theme';
@include mat-core();

.red {
    color: mat-color($mat-red, 500, 1);
}

.warn {
   color: mat-color($warn);
}

[csabattilas]

@leocaseiro thanks

[artem-galas]

@leocaseiro Thanks for your idea.
But could you please explain, how to make two validation message?
For example, I have such a form:

<form [formGroup]="signUpForm" class="sign-up" (ngSubmit)="signUp(signUpForm)" >
      <md-input formControlName="fullName" placeholder="Full name">
        <md-hint *ngIf="signUpForm.hasError('required','fullName')" [ngStyle]="{'color': 'red'}" align="start">Full name is required</md-hint>
      </md-input>
      <md-input formControlName="userName" placeholder="User name">
        <md-hint *ngIf="signUpForm.hasError('required','userName')" [ngStyle]="{'color': 'red'}" align="start">User name is required</md-hint>
      </md-input>
      <md-input formControlName="email" type="email" placeholder="Email">
        <md-hint *ngIf="signUpForm.hasError('required','email')" [ngStyle]="{'color': 'red'}" align="start">Email is required</md-hint>
        <md-hint *ngIf="signUpForm.hasError('pattern','email')" [ngStyle]="{'color': 'red'}" align="start">example@mail.com</md-hint>
      </md-input>
</form>

[leocaseiro]

Hi @artem-galas,

I actually made my message error dynamic, so I have a single <md-hint>.

In that case, I update the message depending on the error.

If it's not clear, I'm happy to send you an example.

[artem-galas]

@leocaseiro Thanks, I got the idea. It would be awesome if you send me a snippet.

[leocaseiro]

export class AppComponent {

  model = { email: '' }

  validateEmail(email) {
    var re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    return re.test(email);
  }

  errorMessageEmail() {
    if (this.model.email === '') {
      return 'Email is required!';
    } else if (!this.validateEmail(this.model.email)) {
      return 'Email is invalid!';
    } else {
      return false;
    }
  }
}

  <form>
    <md-input placeholder="Email" [(ngModel)]="model.email" name="email" type="email" required>
      <md-hint *ngIf="errorMessageEmail()" [ngStyle]="{'color': 'red'}" align="start">{{errorMessageEmail()}}</md-hint>  
    </md-input>
  </form>

Here is the plunker: http://plnkr.co/edit/ZKd1OR2rpey3WddbEpRv?p=preview

PS: It's just a snippet for demo purpose, use ReactiveFormsModule for validation.

[mcalmus]

md-hint works fine for inputs, but there's no similar facility for select items, checkboxes, etc.

[DmitryEfimenko]

I created directives similar to ng1's ng-messages. Here's an example how you'd use it:

<md-input-container>
  <input mdInput formControlName="name" placeholder="Account name" required type="text">
  <md-hint [val-messages]="myForm.get('name')">
    <span val-message="required">Required</span>
  </md-hint>
</md-input-container>

The example above conviniently slaps it on md-hint, but you can put it on any html element.
I know this does not directly addresses the issue, but hopefully helps a bit.

[abqadeer]

How to divider color for md-select? I have got validations to work on inputs on submit but for select it works only if you have touched it once atleast and then click submit.

[tmburnell]

@abqadeer, can you give an example of how you got the validations on submit to work?
I could not figure out how to set touched on elements on submit for it to work correctly.

however i did the following for the error message colors:
+input did not mark errors in red
+select does not have a container, so not md-hint. So i created one that mocked it.

md-input-container.ng-touched.ng-invalid {
	/deep/ .mat-input-placeholder {
		color: $error;
	}

	/deep/ .mat-input-underline {
		border-top-width: 1px;
		border-color: $error;
	}

	/deep/ .mat-input-ripple {
		background-color: $error;
	}

	md-hint {
		color: $error;
		float: right;
	}
}

div.select-container {
	position: relative;

	.md-hint {
		color: $error;
		padding-top: 2px;
		font-size: 75%;
		position: absolute;

		right: 0;
	}
}

[tmburnell]

I just realized they they added md-error ... and the need for some of my css is no longer needed. However I still dont know how to make the input trigger in error when you have not touched it.

[coder925]

@tmburnell , there is a workaround described in #4232 for allowing the md-error to show an error even if the control is not touched.

[CDDelta]

@tmburnell running .valid on the input form will also show the md-error on all invalid inputs. (*for reactive forms)

[onalbi]

If this can help someone, md-error works fine with formControl, for example:

[HTML]

          <fieldset [disabled]="isSubmitting">
                <md-input-container class="full-width">
                    <md-error>{{tagField.errors ? tagField.errors.missedTag : null}}</md-error>
                    <input mdInput class="article-tags" type="text" placeholder="Enter tags"
                           [formControl]="tagField" (keyup.enter)="addTag()"/>
                    <md-chip-list>
                        <md-chip *ngFor="let tag of article.tags">
                            <md-icon (click)="removeTag(tag)">delete</md-icon>
                            <span>{{tag}}</span>
                        </md-chip>
                    </md-chip-list>
                    <md-hint>Press [enter] to add the tag</md-hint>
                </md-input-container>
            </fieldset>
            <fieldset [disabled]="isSubmitting">
                <button md-raised-button type="button" (click)="submitForm()" [disabled]="checkValidForm()">
                    <md-icon>publish</md-icon>
                    <span>Submit</span>
                </button>
            </fieldset>

[TS]

this.fb.group({tagField: []});

checkValidForm(): boolean {
        if (this.article.tags.length < 1) {
            this.tagField.setErrors({'missedTag': 'Please add at last one tag'});
        }
        return !this.articleForm.valid || this.article.tags.length < 1;
}

[mmalerba]

Closing this since we now have <md-error> and a section in the input documentation on how to use it

[davorzdralo]

@mmalerba - we do? The documentation on https://material.angular.io/components/input/overview is broken, I can't see example code and Plunkers don't do anything, and docs don't even try to explain how to have multiple messages.

[steve-todorov]

The docs seems to be broken here as well. Was looking forward to experimenting with this feature, but will have to wait a while until everything is back to normal.

[atbe]

@davorzdralo Confirmed still broken on my end.

[willshowell]

@davorzdralo @steve-todorov @atbe

Dunno why that particular example is broken (cc @amcdnl), but the source is here:

https://github.com/angular/material2/tree/master/src/material-examples/input-errors

and here's the example in a plunker:

https://plnkr.co/edit/mS8vyDKHLUhC9YOr84Aw?p=preview

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