Strict validation of incoming data is very essential and expected part of any software system. You must be very sure about the nature of data especially the one which is coming from another source.
We all do validation for simple data like email, name, date of birth, etc but while development there are many occurrences where we need to validate other stuff as well ( JSON, Base64, UUID, etc).
Node validator
Chris O’Hara authored this nodejs module which is really very helpful package. This package covers most of the string sanitization and validation. Following are example of some :
| isEmail | returns true/false |
| isURL | returns true/false |
| isIP | returns true/false |
| isBase64 | returns true/false |
| isFloat | returns true/false |
| isDivisibleBy | returns true/false |
| isNull | returns true/false |
| isUUID | returns true/false |
| isJSON | returns true/false |
Some useful sanitization :
| toDate | Converst to date format. |
| escape | Often used for SQL queries |
| toFloat | Converts to float |
Visit their official Github page and you can see more about it !
Example application :
We are going to build simple node application that consist of form elements such as email,name and at the back-end we will validate the input data coming from forms.
{
"name": "validator-for-node",
"version": "0.0.1",
"dependencies": {
"body-parser": "^1.12.0",
"express": "^4.12.0",
"validator": "^3.32.0"
}
}
Install dependencies by runningnpm install on Terminal or Command prompt.
On the form submit action it will redirect to “validateform” and we need to manage this at our Node.js backend. Here is our Server file.
var express = require("express");
var validation = require("validator");
var bodyParser = require("body-parser");
var app = express();
app.use(bodyParser.urlencoded({ extended: false }));
app.get('/',function(req,res){
res.sendFile(__dirname + '/form.html');
});
/* Form will redirect here with Input data */
app.post('/validateform',function(req,res){
if(!validation.isEmail(req.body.email)) {
//True or false return by this function.
res.send("Email is Bad");
} else if(!validation.isAlpha(req.body.user_name)) {
res.send("Name is Bad");
} else {
res.send("Form submitted");
}
});
app.listen(4000,function(){
console.log("Listening at PORT 3000");
});
Running the app:
Run this code by typing node Server.js on terminal and Visit “localhost:3000” to view the app.
Type some bad email such as without ‘@’ and Name which contains numbers and see the output.
Adding it to Client side:
Download the minified file from GitHub and add it to client side using Script tag. Here is snippet for example purpose.
Conclusion:
The only intention behind this post was to save your time from doing extra and repetitive work of validation of strings and various data. Hope this library helps you and saves your time and don’t forget to Fork and star the Project.
