formValidation-required


A required field rule module for the DEGJS formValidation module.

Install

formValidation-required is an ES6 module. Consequently, you'll need an ES6 transpiler (Babel is a nice one) as part of your Javascript workflow.

If you're already using NPM for your project, you can install formValidation-required with the following command:

``
$ npm install @degjs/form-validation-required
`




Usage

After importing, formValidation rule modules can be instantiated by passing an array of names into a formValidation options object:

`js
import formValidation from "@degjs/form-validation";

/ Import the Required rule module /
import required from "@degjs/form-validation-required";

let validationOptions = {
rules: [
required
]
};

/ Instantiate the formValidation module on an element /
let formElement = document.querySelector('.form');
let validationInst = formValidation(formElement, validationOptions);
`

Optionally, default rule settings can be overridden by instantiating the rule as a function and passing options as an object:
`js
let validationOptions = {
rules: [
required({
message: 'This message will override the default rule message.',
events: [
'focusout',
'submit'
]
})
]
};
`

formValidation-required builds upon the HTML5 required validation pattern. Therefore, after instantiating the rule module, a field in the validation instance will be tested by this rule simply by adding a required attribute to the field input.

This rule module contains its own default validation message. However, this message can be overridden by adding a data attribute at the field or form level (in that order of importance).

Sample Markup:
`html


First Name

Submit

`

Options

#### options.message
Type: String
Default: This field is required.
The default message displayed when a field fails this rule's validation test.

#### options.messageAttr
Type: String
Default: data-validation-required-message
The data attribute formValidation will check when determining message hierarchy

#### options.events
Type: Array
Default: ['focusout','submit']
An array of DOM events that will cause the rule to run validation on a field (or the entire form, when using submit). NOTE: focusout should be used in place of blur` due to event bubbling limitations.

For more detailed usage instructions, see the formValidation Usage documentation.