@ngserveio/validation-messages
v9.0.0
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Find more at libraries and examples at [NgServe.io](https://ngserve.io).
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@ngserveio/validation-messages
Find more at libraries and examples at NgServe.io.
This library was generated with Nx.
Purpose
The validation messages project alleviates developers from writing bloated markup for validation messages through a the ngServeValidationDisplay
directive.
See the Video Tutorial on YouTube
Running unit tests
Run nx test shared-ui-validation-display
to execute the unit tests.
Configuration
Import the module NgServeValidationDisplayModule
into the consuming module.
@NgModule({
imports: [NgServeValidationDisplayModule],
})
export class SampleModule {}
ValidationMessageService
The ValidationMessageService
ships with default validation messages.
export const ValidationMessages: { [key: string]: string } = {
required: '{{fieldName}} is required.',
email: '{{fieldName}} is invalid.',
minlength: 'Minimum length is {{requiredLength}}',
maxlength: 'Maximum length is {{requiredLength}}',
min: '{{fieldName}} is less than minimum value of {{min}}.',
max: '{{fieldName}} exceeds maximum value of {{max}}.',
uniqueEmail: '{{value}} is already taken',
exists: '{{fieldName}} {{value}} does not exist',
agreeToTerms: 'You must agree to our terms.',
url: '{{fieldName}} has invalid url',
alphanumeric: '{{fieldName}} must be alphanumeric characters.',
unique: '{{fieldName}} exists and must be unique.',
isNumeric: '{{fieldName}} must be a numeric value',
};
The validation messages consist of the key
being a validation and string being a message template. The message template creates consistency for form validation messages.
Each key
maps to a key on a FormControl's errors property.
The errors
property implements a type of { [key:string]: any }
, so validation errors can supply more information. e.g. min supplies the properties of min
and actual
.
To override these messages, use the addMessages
method on the ValidationMessgeService
.
Adding Messages
import { ValidationMessageService } from '@ngserveio/validation-display';
@NgModule({})
export class SampleModule() {
constructor(private validationMessageService: ValidationMessageService) {
validationMessageService.addMessages({
min: '{{fieldName}} must be less than {{min}}. {{actual}} was entered',
isBetween: '{{fieldName}} must be between {{min}} and {{max}}.',
required: 'Please enter a {{fieldName}}.'
});
}
}
ValidationDisplayDirective
The validation display directive alleviates the need to bloat html markup in form. In order to display the validation message, add the ngServeValidationDisplay
providing the control and fieldName
. The fieldName
will be supplied as part of the message if the message template includes it.
Component Markup
<div [formGroup]="myForm">
<label>Email</label>
<input type="email" formControlName="email">
<span [ngServeValidationDisplay]="emailControl" fieldName="Email">
</div>
Component Code
@Component({
template: './sample.component.html',
})
export class SampleComponent {
public myForm = new FormGroup({
email: new FormControl('', [Validators.required, Validators.email]),
});
public get emailControl(): AbstractControl {
return this.myForm.get('email');
}
}
Validators
The following validators are also shipped in this package.
emptyOrWhiteSpace
Checks if the control has a value that isn't white space. This will return { required: true }
if invalid, so it will use the required
message template.
isNumeric
Checks if the value is numeric. Returns { isNumeric: true }
using the isNumeric
message template.
requiredIf
Uses a predicate check on the condition supplied and checks if controls' value is empty or whitespace.
public sampleForm = new FormGroup({
email: new FormControl('', [
requiredIf((ctrl: AbstractControl) => {
const siblingControl = ctrl.parent.get('sibling');
return siblingControl.value;
}
])
});