README.md

valid-param.js

A convenient approach to validating object properties in javascript. This method was built with an emphasis on validating function parameters passed as an object (object literal syntax).

Installation

NPM

npm install valid-param.js

From CDN

1. Visit https://cdnjs.com/libraries/valid-param.js
2. Add CDN link to your site with <script>

Using build / minified version

1. Download valid-param.min.js
2. Add to your site with <script>

Tip

valid-param.js was designed with the intent of validating function parameters passed as properties of an object, but can be used to validate properties of any object.

Use

Simply call the ValidParam class and pass in the parameters object as the first argument, along with a 'type assignment' object as the second argument. The 'type assignment' object associates each expected parameter with an acceptable type. If any parameter value is passed with an incorrect type, the appropriate error is thrown.

new ValidParam(parameters, {
	name: 'string',
	age: 'number',
})	

The class is best used as the first bit of logic inside the function or method.

function getProfileBlock(parameters = {}) {
	new ValidParam(parameters, {
		name: 'string',
		age: 'number',
	})
	
	return `${name}<br>${age}`
}	

Assigning types

Parameter types are assigned inside of the 'type assignment' object. The key should refer to the paramenter name while the value refers to that parameter's type assignment.

	{
		age: 'number',
	}

Default types

If you would like to assign a default type to non-typed parameters, you can you simply add a default property to the 'type assignment' object.

	{
		age: 'number',
		default: 'string'
	}

Any parameter (or object-property) that is not explicitly typed in the 'type assignment' object will default to this setting. If a default is not set, all non-typed paramaters will be ignored.

Multiple types

To assign multiple acceptable types, simply separate each type with a | mark.

	{
		age: 'string|number',
	}

Allowing null values

A parameter can be made nullable by simply adding the null type to the assignment string.

	{
		age: 'string|number|null',
	}

If there is only a single acceptable type, then you can simply add ? at the beginning of the string.

	{
		age: '?string',
	}

Assigning mixed and any

If a parameter can be of any type, including null, programmers may use the mixed or any types. Either will allow any value through, regardless of type, as long as the parameter is defined.

	{
		age: 'mixed',
	}

Assignable Types:

• string (or str)
• number (or num,int)
• boolean (or bool)
• array (or arr)
• object (or obj)
• mixed (or any)

Contribute

Pull requests are welcomed to this project