Gateman NPM | npm.io

Gateman

Simple and easiest JSON validator

Documentation

Installation

npm install gateman

Basic Usage

var gateman=require('gateman');
var validate=gateman({
    name:"string|minlength:5|required",
    age:"number|required",
    dob:"date",
    password:"required|minlength:4",
    confirm_password:"same:password",
    address:{
        country:"string",
        city:"string|required",
    },
    tags:["string|$maxcount:2"]
});
var err=validate({
    name:"Koushik",
    age:28,
    dob:"1990-04-01",
    address:{
        country:"India"
    },
    password:"abcd",
    confirm_password:"abcd",
    tags:["javascript","json"]
});
if(!err) console.log("Valid");
else console.log(err);

Rules

Rule	Description	Param Type	Example
string	String type check		`{ name: "string" }`
number	Number type check		`{ age: "number" }`
date	Date or not		`{ dob: "date" }`
email	Email or not		`{ email: "email" }`
required	Value given or not		`{ address: "required" }`
requiredif	Required if another field is given	string	`{ city: "string", address: "string \| requiredif: city" }`
min	Minimum value check	number	`{ price: "min:100" }`
max	Maximum value check	number	`{ price: "max:1000" }`
minlength	Minimum length check	number	`{ password: "minlength:5" }`
maxlength	Maximum length check	number	`{ description: "maxlength:200" }`
digit	Number of digit check	number	`{ pincode: ["digit:6"] }`
mindigit	Minimum number of digit check	number	`{ amount: ["mindigit:3"] }`
maxdigit	Maximum number of digit check	number	`{ amount: ["maxdigit:6"] }`
uppercase	All characters are uppercase or not		`{ name: "uppercase" }`
lowercase	All characters are lowercase or not		`{ name: "lowercase" }`
same	Value to be same as other field	string	`{ password: "minlength:5", confirm_password: "same:password" }`
accepted	Value to be truthy(eg. `true` or `1` )		`{ terms: "accepted" }`
range	Value between 2 numbers(inclusive)		`{ price: "range : 100 : 200" }`

Array Rules

Array rules operate on whole array and are prefixed with $ symbol.

Rule	Description	Param Type	Example
required	Atleast one array item is required		`{ address: ["$required"] }`
count	Array length check	number	`{ tags: ["$count:2"]}`
mincount	Minimum array length check	number	`{ tags: ["$mincount:2"] }`
maxcount	Maximum array length check	number	`{ tags: ["$maxcount:2"] }`

Using array rules in keys

{
	favourites:[
        {
            "$mincount": 2,
            "$maxcount": 10,
            rating:"number | required"
        }
    ]
}

a valid json with respect to the above schema would be

{
	favourites:[
        {
            rating: 44
        },{
            rating: 22
        }
    ]
}

Using with expressjs

var express = require('express');
var app = express();

var bodyParser = require('body-parser');
app.use(bodyParser.json());

var gateman = require('gateman');
//the following higher order function creates expressjs middleware
var validate = (schema, customMessages, customValidators)=>{
	var validatorFn = gateman(schema, customMessages, customValidators);
	return (req,res,next)=>{
		req.errors = validatorFn(req.body,{flatten:true});
		next();
	}
}
//use the middleware
app.post('/demo', validate({
    email:"email|required",
    location:"string|required|minlength:10"
}), (req, res) => {
	if(req.errors){
		return res.status(422).json({
			success: false,
			error: req.errors
		});
	}
	res.json({
		success:true,
		data:req.body
	});
});

app.listen(8080, () => {
	console.log(name + ' is live at 8080');
});