rc@73: /*!
rc@73:  * method-override
rc@73:  * Copyright(c) 2010 Sencha Inc.
rc@73:  * Copyright(c) 2011 TJ Holowaychuk
rc@73:  * Copyright(c) 2014 Jonathan Ong
rc@73:  * Copyright(c) 2014 Douglas Christopher Wilson
rc@73:  * MIT Licensed
rc@73:  */
rc@73: 
rc@73: /**
rc@73:  * Module dependencies.
rc@73:  */
rc@73: 
rc@73: var methods = require('methods');
rc@73: var parseurl = require('parseurl');
rc@73: var querystring = require('querystring');
rc@73: var vary = require('vary');
rc@73: 
rc@73: /**
rc@73:  * Method Override:
rc@73:  *
rc@73:  * Provides faux HTTP method support.
rc@73:  *
rc@73:  * Pass an optional `getter` to use when checking for
rc@73:  * a method override.
rc@73:  *
rc@73:  * A string is converted to a getter that will look for
rc@73:  * the method in `req.body[getter]` and a function will be
rc@73:  * called with `req` and expects the method to be returned.
rc@73:  * If the string starts with `X-` then it will look in
rc@73:  * `req.headers[getter]` instead.
rc@73:  *
rc@73:  * The original method is available via `req.originalMethod`.
rc@73:  *
rc@73:  * @param {string|function} [getter=X-HTTP-Method-Override]
rc@73:  * @param {object} [options]
rc@73:  * @return {function}
rc@73:  * @api public
rc@73:  */
rc@73: 
rc@73: module.exports = function methodOverride(getter, options){
rc@73:   options = options || {}
rc@73: 
rc@73:   // get the getter fn
rc@73:   var get = typeof getter === 'function'
rc@73:     ? getter
rc@73:     : createGetter(getter || 'X-HTTP-Method-Override')
rc@73: 
rc@73:   // get allowed request methods to examine
rc@73:   var methods = options.methods === undefined
rc@73:     ? ['POST']
rc@73:     : options.methods
rc@73: 
rc@73:   return function methodOverride(req, res, next) {
rc@73:     var method
rc@73:     var val
rc@73: 
rc@73:     req.originalMethod = req.originalMethod || req.method
rc@73: 
rc@73:     // validate request is on allowed method
rc@73:     if (methods && methods.indexOf(req.originalMethod) === -1) {
rc@73:       return next()
rc@73:     }
rc@73: 
rc@73:     val = get(req, res)
rc@73:     method = Array.isArray(val)
rc@73:       ? val[0]
rc@73:       : val
rc@73: 
rc@73:     // replace
rc@73:     if (method !== undefined && supports(method)) {
rc@73:       req.method = method.toUpperCase()
rc@73:     }
rc@73: 
rc@73:     next()
rc@73:   }
rc@73: }
rc@73: 
rc@73: /**
rc@73:  * Create a getter for the given string.
rc@73:  */
rc@73: 
rc@73: function createGetter(str) {
rc@73:   if (str.substr(0, 2).toUpperCase() === 'X-') {
rc@73:     // header getter
rc@73:     return createHeaderGetter(str)
rc@73:   }
rc@73: 
rc@73:   return createQueryGetter(str)
rc@73: }
rc@73: 
rc@73: /**
rc@73:  * Create a getter for the given query key name.
rc@73:  */
rc@73: 
rc@73: function createQueryGetter(key) {
rc@73:   return function(req, res) {
rc@73:     var url = parseurl(req)
rc@73:     var query = querystring.parse(url.query || '')
rc@73:     return query[key]
rc@73:   }
rc@73: }
rc@73: 
rc@73: /**
rc@73:  * Create a getter for the given header name.
rc@73:  */
rc@73: 
rc@73: function createHeaderGetter(str) {
rc@73:   var header = str.toLowerCase()
rc@73: 
rc@73:   return function(req, res) {
rc@73:     // set appropriate Vary header
rc@73:     vary(res, str)
rc@73: 
rc@73:     // multiple headers get joined with comma by node.js core
rc@73:     return (req.headers[header] || '').split(/ *, */)
rc@73:   }
rc@73: }
rc@73: 
rc@73: /**
rc@73:  * Check if node supports `method`.
rc@73:  */
rc@73: 
rc@73: function supports(method) {
rc@73:   return method
rc@73:     && typeof method === 'string'
rc@73:     && methods.indexOf(method.toLowerCase()) !== -1
rc@73: }