Gateman

Simple and easiest JSON validator

Documentation

see docs.md

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');
});

WIP