MaxLengthValidator
directive
A directive that adds max length validation to controls marked with the maxlength attribute. The directive is provided with the NG_VALIDATORS multi-provider list.
See also
NgModules
Selectors
[maxlength][formControlName][maxlength][formControl][maxlength][ngModel]
Properties
| Property | Description |
|---|---|
@Input()maxlength: string | number |
Tracks changes to the the maximum length bound to this directive. |
Description
Adding a maximum length validator
The following example shows how to add a maximum length validator to an input attached to an ngModel binding.
<input name="firstName" ngModel maxlength="25">Methods
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ngOnChanges()
|
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|---|---|---|---|
A lifecycle method called when the directive's inputs change. For internal use only. |
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|
changes |
SimpleChanges |
A object of key/value pairs for the set of changed inputs. |
Returns
void
|
validate()
|
|||
|---|---|---|---|
Method that validates whether the value exceeds the maximum length requirement. |
|||
|
control |
AbstractControl |
Returns
ValidationErrors | null
|
registerOnValidatorChange()
|
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|---|---|---|---|
Registers a callback function to call when the validator inputs change. |
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|
fn |
() => void |
The callback function |
Returns
void
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Licensed under the Creative Commons Attribution License 4.0.
https://v9.angular.io/api/forms/MaxLengthValidator