express-htaccess-middleware/lib/RewriteCond.js

An express middleware that interprets .htaccess rewrite rules.

'use strict';

var _ = require('lodash');
var url = require('url');


function RewriteCond(baseCondition) {
  _.assign(this, baseCondition);

  this.doMatch = true;
  this.envVarRegexp = /%{ENV:(.+)}$/;

  if (this.pattern[0] === '!') {
    this.pattern = this.pattern.substring(1);
    this.doMatch = false;
  } else if (this.pattern[0] === '=') {
    this.pattern = '^' + this.pattern.substring(1) + '$';
  }

  if (this.flags.indexOf('NC') !== -1) {
    this.re = new RegExp(this.pattern, 'i');
  } else {
    this.re = new RegExp(this.pattern);
  }

  this.matchResult = null;
}


RewriteCond.prototype.matches = function (req) {
  var value = '';
  var envMatch = this.envVarRegexp.exec(this.variable);

  if (envMatch) {
    var envVar = envMatch[1];
    value = process.env[envVar] || '';
  } else if (this.variable === '%{HTTP_USER_AGENT}') {
    value = req.headers['user-agent'];
  } else if (this.variable === '%{REQUEST_METHOD}') {
    value = req.method.toUpperCase();
  } else if (this.variable === '%{HTTP_REFERER}') {
    value = req.headers.referer;
  } else if (this.variable === '%{HTTP_HOST}') {
    value = req.headers.host;
  } else if (this.variable === '%{REQUEST_URI}') {
    value = url.parse(req.url).pathname;
  } else if (this.variable === '%{THE_REQUEST}') {
    value = req.url;
  } else if (this.variable === '%{QUERY_STRING}') {
    value = url.parse(req.url).query;
  }

  this.matchResult = this.re.exec(value);
  if (this.matchResult === null && !this.doMatch) {
    return true;
  } else if (this.matchResult !== null && this.doMatch) {
    return true;
  }

  return false;
};

module.exports = RewriteCond;