summon-middleware

Dynamically enable or disable express middlewares

This wrapper allows you to dynamically enable or disable an express or connect middleware or an array of them. In some circumstances you would use one or more middlewares only if some conditions are met.

Installation

If you want to use summon-middleware you have to install it. There are two methods to do that:

First method

In your package.json add the following item for the latest version:

"summon-middleware": "*"

or, if you want a specific version, just add an item like the following, specifying the version number:

"summon-middleware": "2.0.2"

then launch this command:

npm install

Second method

Just launch this command:

npm install summon-middleware --save

Use

summonMiddleware(middleware, predicate)

• middleware {Function|Function[]} an express or connect middleware or an array of them.
• predicate {Function} a function that returns a boolean value and that represents the condition for which the provided middlewares have to be used or not.
• returns: a single middleware or an array of middlewares.

If the parameters' type does not match with those required, an error will be thrown. In pariticular, the error will be an instance of SummonMiddlewareError.

Examples

Providing a single middleware

var summonMiddleware = require('summon-middleware')
 
var express = require('express')
var app = express()
 
var responsePoweredBy = require('response-powered-by')
var POWERED_BY = "@NickNaso"
 
app.use(summonMiddleware(responsePoweredBy(POWERED_BY), function () {
  // some instructions...
  if (<your condition>) {
    return true
  }
  return false
}))

Providing an array of middlewares

var summonMiddleware = require('summon-middleware')
 
var express = require('express')
var app = express()
 
var responsePoweredBy = require('response-powered-by')
var POWERED_BY = "@NickNaso"
var responseTime = require('response-time')
 
var myMiddlewares = [
  responsePoweredBy(POWERED_BY),
  responseTime()
]
 
app.use(summonMiddleware(myMiddlewares, function () {
  // some instructions...
  if (<your condition>) {
    return true
  }
  return false
}))