ng-validator

A set of Angular (>=2) validators with support on input files in reactiveforms, this package is split in commonValidators, ArrayValidators, AdvancedValidators and FileValidators, it has a directive that gives funcionality to inputs files to react to changes as any other inputs.

Installation

    $ npm install ng-validator --save

Usage

Classes

• CommonValidators
• ArrayValidators
• AdvancedValidators
• FileValidators

These classes will only import them into the componets to use. For example:

    // you can import the components to use
 
    import { CommonValidators, ArrayValidators } from 'ng-validator';

CommonValidators

The class commonValidators contains a few methods to use:

requiredTrim

It validates a field to be required, but it making a trim.

    // Example
 
    this.formBuilder.group({
        name: ['', CommonValidators.requiredTrim]
    });

greaterThan

It validates a field to be greater than X number.

    // Example
 
    this.formBuilder.group({
        age: ['', CommonValidators.greaterThan(17)]
    });

Note: This validator internally evaluates in this way, control > 17, if you want compare control >= 17, the method receives a second optional argument of boolean type.

    // Example >=
 
    this.formBuilder.group({
        age: ['', CommonValidators.greaterThan(17, true)]
    });

lessThan

It validates a field to be less than X number.

    // Example
 
    this.formBuilder.group({
        age: ['', CommonValidators.lessThan(17)]
    });

Note: This validator internally evaluates in this way, control < 17, if you want compare control <= 17, the method receives a second optional argument of boolean type.

    // Example <=
 
    this.formBuilder.group({
        age: ['', CommonValidators.lessThan(17, true)]
    });

equalsTo

It validates a field to be equals to X value (string || number).

    // Example
 
    this.formBuilder.group({
        age: ['', CommonValidators.equalsTo(17)]
    });

Note: This validator internally evaluates in this way, control == 17, if you want compare control === 17, the method receives a second optional argument of boolean type.

    // Example ===
 
    this.formBuilder.group({
        age: ['', CommonValidators.equalsTo(17, true)]
    });

differentTo

It validates a field to be different to X value (string || number).

    // Example
 
    this.formBuilder.group({
        age: ['', CommonValidators.differentTo(17)]
    });

Note: This validator internally evaluates in this way, control != 17, if you want compare control !== 17, the method receives a second optional argument of boolean type.

    // Example !==
 
    this.formBuilder.group({
        age: ['', CommonValidators.differentTo(17, true)]
    });

contains

It validates a field to contains a chunk of X value into the string.

    // Example
 
    this.formBuilder.group({
        title: ['', CommonValidators.contains('world')]
    });
 
    /*
        If the input contains "Hello world", the validator evaluates as correct.
    */

startsWith

It validates a field to starts with X value in the string.

    // Example
 
    this.formBuilder.group({
        title: ['', CommonValidators.startsWith('Hello')]
    });
 
    /*
        If the input starts with "Hello", the validator evaluates as correct.
    */

endsWith

It validates a field to ends with X value in the string.

    // Example
 
    this.formBuilder.group({
        title: ['', CommonValidators.endsWith('world')]
    });
 
    /*
        If the input ends with "world", the validator evaluates as correct.
    */

isNumber

It validates a field to be a number.

    // Example
 
    this.formBuilder.group({
        age: ['', CommonValidators.isNumber]
    });

isEmail

It validates a field to be an email.

    // Example
 
    this.formBuilder.group({
        email: ['', CommonValidators.isEmail]
    });

isURL

It validates a field to be an URL.

    // Example
 
    this.formBuilder.group({
        url: ['', CommonValidators.isURL]
    });

isPhone

It validates a field to be a phone.

    // Example
 
    this.formBuilder.group({
        phone: ['', CommonValidators.isPhone]
    });

ArrayValidators

maxLength

It validates a formArray to have a max length of X number.

    // Example
 
    this.formBuilder.group({
        list: this.formBuilder.array( [], ArrayValidators.maxLength(3) )
    });

minLength

It validates a formArray to have a min length of X number.

    // Example
 
    this.formBuilder.group({
        list: this.formBuilder.array( [], ArrayValidators.minLength(3) )
    });

betweenLength

It validates a formArray to have a min and max length between X and Y numbers.

    // Example
 
    this.formBuilder.group({
        list: this.formBuilder.array( [], ArrayValidators.betweenLength(1, 3) )
    });

equalsToSomeGroupKey

It validates a formArray that least one property into its elements contains the X defined value. The method receives three arguments, the property of formGroup (first), the value to compare (second) and de strict mode validation (third).

    // Example
    // Each element is a formGroup, but for quick example, It will contain literals objects
    let myArray = [
        {
            a: 1,
            b: 2
        },
        {
            a: 4,
            b: 8
        }
    ];
 
    this.formBuilder.group({
        list: this.formBuilder.array( myArray, ArrayValidators.equalsToSomeGroupKey('a', 4) )
    });
 
    /*
        be aware:
 
        - If the property does not exist, you'll receive the following object { "equalsToSomeElementInGroup": true, "err": "Property invalid" }. Make sure the property exists either in the current time or in the future
    */

Note: This validator internally evaluates in this way, control == 17, if you want compare control === 17, the method receives a third optional argument of boolean type.

equalsToSomeElement

It validates a formArray that least one property into its elements contains the X defined value. The method receives two arguments, the value to compare (first) and the strict mode validation (second).

    // Example
    // Each element is a formControl, but for quick example, It will contain literals values
    let myArray = [
        'a',
        'b',
        'c'
    ];
 
    this.formBuilder.group({
        list: this.formBuilder.array( myArray, ArrayValidators.equalsToSomeElement('a') )
    });

Note: This validator internally evaluates in this way, control == 17, if you want compare control === 17, the method receives a second optional argument of boolean type.

keyExistsInGroups

It validates a formArray by checking if contains the key specified in all groups.

    // Example
    // Each element is a formGroup, but for quick example, It will contain literals objects
    let myArray = [
        {
            a: 1,
            b: 2
        },
        {
            a: 4,
            b: 8
        }
    ];
 
    this.formBuilder.group({
        list: this.formBuilder.array( myArray, ArrayValidators.keyExistsInGroups('a') )
    });

keyExistsInAtLeastOneGroup

It validates a formArray by checking if contains the key specified in at least one group.

    // Example
    // Each element is a formGroup, but for quick example, It will contain literals objects
    let myArray = [
        {
            a: 1,
            b: 2
        },
        {
            a: 4,
            b: 8
        }
    ];
 
    this.formBuilder.group({
        list: this.formBuilder.array( myArray, ArrayValidators.keyExistsInAtLeastOneGroup('a') )
    });

AdvancedValidators

This class is one of the most interesting, It allows the interaction with others fields of the form.

equalsToField

It compare the value of the current field with other specified field and validates that be equals.

    // Example
 
    this.formBuilder.group({
        password: [ '' ],
        comparePassword: ['', AdvancedValidators.equalsToField('password')]
    });
 
    /*
        Note: If the specified field doesn't exists, It throws an error
    */

👂 Listeners

In this example (above) the comparePassword field compares its value with the password field, if the values are differents then the validation is triggered.

This validator will only be triggered everytime the field changes (comparePassword), but, what happen when the password field changes?, the comparePassword field will never meet the new value of the password field, It will only meet the value if the comparePassword field presents a change.

For example, If the password field contains 123 value, then 12 is written as value in the comparePassword field, the validator indicates that value isn't the same as the password field. Ok, The validator is working, but, what happens if return to the password field and a change happens?, and now 123 is written, the comparePassword field doesn't listens the new change of the password field. Why?. Because the validators are triggered when they detect changes in the fields where they were assigned. No problem, there is a solution for this, Listeners.

The most of methods of the AdvancedValidators class receives a argument that indicate the name of the listener for that field.

    // Example
 
    this.formBuilder.group({
        password: [ '' ],
        comparePassword: ['', AdvancedValidators.equalsToField('password', 'myListener')]
    });

In the example above, it was added a second argument, that argument creates a listener with the name myListener, now any change of the password field will be notified to the comparePassword field and then the validator will be triggered each that the password field change.

Internally, a listener is created that is linked to the field indicated as the first argument, in this case the password field. It's recommended to name the listener with a descriptive name for the linked field.

Another recommendation is always delete the listeners that you won't use, to free space. To do this, use the destroyListener method.

    AdvancedValidators.destroyListener('MyListener');

If you want destroy all listener, you can use the destroyListeners method.

    // you could put this methods in the ngDestroy if you want
    ngDestroy() {
        AdvancedValidators.destroyListeners();
    }

If you want to watch all the listeners, you can use the listListeners method.

    AdvancedValidators.listListeners();

There is another alternative to notify to other fields. The notifyTo method, this method doesn't creates listeners, it only performs an update to all fields subscribed to it. The notifyTo method receives a array of fields.

    AdvancedValidators.notifyTo(['field1', 'field2', 'field3']);

differentToField

It compare the value of the current field with other specified field and validates that be different.

    // Example
 
    this.formBuilder.group({
        oldPassword: [ '' ],
        newPassword: ['', AdvancedValidators.differentToField('oldPassword')]
    });
 
    /*
        Note: If the specified field doesn't exists, It throws an error
 
        differentToField(field, listener?)
    */

Note: The differentToField method can receives a second argument for create a listener.

requirePresentField

It validates the presence of a field.

    // Example
 
    this.formBuilder.group({
        currency: ['', AdvancedValidators.requirePresentField('price')]
    });
 
    /*
        Note: If the specified field doesn't exists, It throws an error
 
        In this example, the currency field requires the presence of price field
    */

Note: The requirePresentField method doesn't require a listener, the reason is because when a new field is added to the form, the form is updated, therefore, all fields are updated.

requireValidField

It validates that the current field will be valid if the specified field is valid.

    // Example
 
    this.formBuilder.group({
        email: [''],
        confirmEmail: ['', AdvancedValidators.requireValidField('email')]
    });
 
    /*
        Note: If the specified field doesn't exists, It throws an error
 
        In this example, the confirmEmail field is valid if the email field is valid.
    */

FileValidators

This class has methods really useful for files. The problem with Angular is that hasn't support for input file, if you want to use a input file with a reactiveforms, you'll notice that the reactiveforms doesn't present any change when you select one file. It seems that reactiveForms doesn't working with input file, this package gives support for it, it contains a directive that you have import on each module where you want to use it.

    // you only have to import it and add it to imports array
    import { FileControlModule } from 'ng-validator';
 
    imports: [ FileControlModule ]

Once this is done, the input files will start to working.

Now, you can use the following methods.

requiredFile

It validates that the field requires at least one file.

    // Example
 
    this.formBuilder.group({
        photo: [null, FileValidators.requiredFile]
    });

allowExtensions

It validates that the field allows only the specified extensions.

    // Example
 
    this.formBuilder.group({
        photo: [null, FileValidators.allowExtensions(['png', 'jpeg'])]
    });

minSize

It validates that the field allows as minimum the specified size.

    // Example
 
    this.formBuilder.group({
        photo: [null, FileValidators.minSize(2, 'MB')]
    });

You can specified the type of Bytes you want to use, the following list shows the posibles options, by default the second argement use 'B':

Label	value
B	1 Byte
KB	1024 Bytes
MB	1048576 Bytes
GB	1073741824 Bytes
TB	1099511627776 Bytes

maxSize

It validates that the field allows as maximum the specified size.

    // Example
 
    this.formBuilder.group({
        photo: [null, FileValidators.maxSize(2, 'MB')]
    });

minFiles

It validates that the field allows as minimum a number of files.

    // Example
 
    this.formBuilder.group({
        gallery: [null, FileValidators.minFiles(2)]
    });

maxFiles

It validates that the field allows as maximum a number of files.

    // Example
 
    this.formBuilder.group({
        gallery: [null, FileValidators.maxFiles(5)]
    });

Async Methods

This class contains asynchonous validators.

asyncMinWidthImage

It validates that the width of a image be as minimum to specified value.

    // Example
 
    this.formBuilder.group({
        gallery: [null, null, FileValidators.asyncMinWidthImage(500)]
    });

Note: The asynchonous validators are puts in the thrid position of the formControl

asyncMaxWidthImage

It validates that the width of a image be as maximum to specified value.

    // Example
 
    this.formBuilder.group({
        gallery: [null, null, FileValidators.asyncMaxWidthImage(500)]
    });

asyncMinHeightImage

It validates that the height of a image be as minimum to specified value.

    // Example
 
    this.formBuilder.group({
        gallery: [null, null, FileValidators.asyncMinHeightImage(500)]
    });

asyncMaxHeightImage

It validates that the height of a image be as maximum to specified value.

    // Example
 
    this.formBuilder.group({
        gallery: [null, null, FileValidators.asyncMaxHeightImage(500)]
    });

Issues

    https://github.com/Lugriz/ng-validator/issues