Validator-provider NPM

Validator Provider (React)

High-Order Component (Provider) to validate components inside a container (Ex.: Form). It's going to provide a way to validate the childrens without knowing them and have no "references" to them without using Redux or any other Plugin.

This works using the High-Order Component pattern, so all of your Components to be validated and the validator must be stateful.

Installation

Install the dependency on your project

npm install --save validator-provider

Usage

Lets see an example, where you got a Form component (validator) and an CustomInput (validated) component that needs to be validated.

const { ValidatorProvider } = require('validator-provider');
const Form = require('FormComponent');
const CustomInput = require('CustomInput');

const Page = (props) => (
  <ValidatorProvider>
    <Form method="POST">
      <label>
        <CustomInput />
      </label>
    </Form>
  </ValidatorProvider>
);

Fist we need to understand that you have two types of Component:

validator: This is the component that is going to check that all the components inside are valid
validated: This is the component that is going to execute the validations

Injections

Continue with the example, you have two injections possibles:

injectValidator: For the validator component
injectValidations: For the validated components

We need to inject the Components to work:

Form Component

You need to wrap your module.exports Component Class with injectValidator method. This method will wrap your Component inside another one, but passing a prop called validatorProvider.

This validatorProvider is going to provide two methods:

isValid: Return a boolean if all the components are valid or invalid. true if valid
getInvalid: Is going to return an array with the component references

Let's continue with the example, if i have a Form that only needs to be submited if the child components are valid, we are going to wrap the components. See the next example:

const React = require('react');
const { injectValidator } = require('validator-provider');

class Form extends React.Component {
  constructor(props) {
    super(props);
    this.onSubmit = this.onSubmit.bind(this);
  }
  
  onSubmit(event) {
    if( !this.props.validatorProvider.isValid() ) {
      event.preventDefault();
    }
  }
  
  render() {
    return (
      <form method={this.props.method} onSubmit={this.onSubmit}>
        {this.props.children}
      </form>
    );
  };
}

module.exports = injectValidator(Form);

See that the Form is only going to be submit if the components are valid.

isValid Method

This method is going to execute the validate method inside the component (validated). In this example, you need to implement the validate method on CustomInput component.

If you dont implement this, you are going to receive a log on the terminal letting you know that you must implement the validate, if not, your component is always valid.

The isValid Method is going to call the getInvalid and check the array length.

CustomInput Component

You need to wrap your module.exports Component Class with injectValidations method. This method will wrap your component inside another and is going to be the one that register your component on the provider.

If you don't wrap the Component that you want to validate inside the inject, the provider is not going to be aware of them.

const React = require('react');
const { injectValidations } = require('validator-provider');

class CustomInput extends React.Component {
  constructor(props) {
    super(props);
    this.validate = this.validate.bind(this);
  }
  
  // MUST RETURN TRUE IF THE VALIDATION IS VALID
  validate() {
    // Validate that is not empty
    return (this.input.value !== '');
  }
  
  render() {
    return (<input value={this.props.value} ref={el => (this.input = el)} />);
  };
}

module.exports = injectValidations(CustomInput);

Here, you can see that the validate function is only checked that the field is not empty.

validate method must return TRUE if it is valid

Validations

You can use the validate method to do the actual validations, or, you can validate the inputs on change and show the messages on real time. If you want this, you can use the validate only to return if valid or not depending on a state variable and get a better performance when validating.

In the next example, i am going to use the validate to send if the component is valid, but not doing the actual validation. I'm using the onChange to validate the Input, and maybe i can show the error message on the HTML too, and leaving the validate only to prevent the form to submit.

const React = require('react');
const { injectValidations } = require('validator-provider');

class CustomInput extends React.Component {
  constructor(props) {
    super(props);
    
    // Set if valid on the state
    this.state = {
      valid: false
    };
    
    this.validate = this.validate.bind(this);
    this.onChange = this.onChange.bind(this);
  }
  
  validate() {
    return this.state.valid;
  }
  
  onChange() {
    // Maybe show the error here too
    this.setState({
      valid: (this.input.value === '')
    });
  }
  
  render() {
    return (<input value={this.props.value} ref={el => (this.input = el)} onChange={onChange} />);
  };
}

module.exports = injectValidations(CustomInput);