Express Query Parameter Middleware

This is a tool to use as a middleware to check the (query) parameter input from an HTTP request in express.

How to use

Install query parameter middleware

npm install express-parameter-middleware --save

Importing the express parameter middleware into your project

You need different imports to use this middleware. We recommend you use different variables.

const EPM = require('express-parameter-middleware');
const Parameter = EPM.Parameter;
const CheckParameters = EPM.CheckParameters;
const Validators = EPM.Validators;

Using the middleware

First using the middleware, initialise each parameter you wish to check. This allows you to create an_array_of objects (with each object representing a parameter)

const Parameters = [
    new Parameter(
        "limit",
        Number,
        [Validators.Number],
        true
    ),
    new Parameter(
        "offset",
        Number,
        [Validators.Number],
        true
    )
];

Then create a new object of the CheckParameters class and insert the Parameters as property:

const LimitAndOffset = new CheckParameters(Parameters);

After this step, you are ready to use it as middleware. Just enter the kind of Check you want to do. done.

app.get('/', LimitAndOffset.CheckQueryParam, function (req, res) {
    res.status(200).send('ok');
});

http://example.com/?limit=10&offset=10

or:

app.get('/:limit/:offset', LimitAndOffset.CheckParam, function (req, res) {
    res.status(200).send('ok');
});

http://example.com/10/10

Custom Validator

You can initialinize your own Validators:

CustomValidator(/regular expression/ , 'Name');

By example:

CustomValidator(/^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$/ , 'IP');

You can use this Validator as you would any other Validator.IP

API

Parameter options

• name: No default value, any clean string;
• type: undefined as default
  • String
  • Number
  • Boolean
  • Symbol
  • null
  • Date
  • Object
  • undefined
  • 'any'
  • Array
• validator: array of possible validators
  • Validator.Base64
  • Validator.DateTime
  • Validator.Email
  • Validator.Number
  • Validator.String
  • Validator.TextOnly (only text, no numbers)
  • Validator.{YourCustomValidator} (This is a self made validator, see Custom Validator)
• required: false by default
  • true
  • false

CheckParameter options

• CheckParam: checks the params in the request
• CheckQueryParam: checks the query params in the request