mach/lib/middleware/rewrite.js

HTTP for JavaScript

"use strict";

var escapeRegExp = require("../utils/escapeRegExp");
var isRegExp = require("../utils/isRegExp");

/**
 * A middleware that provides URL rewriting behavior similar to Apache's
 * mod_rewrite. The pathname of requests that match the given pattern is
 * overwritten with the replacement using a simple String#replace.
 */
function rewrite(app, pattern, replacement) {
  if (typeof pattern === "string") pattern = new RegExp("^" + escapeRegExp(pattern) + "$");

  if (!isRegExp(pattern)) throw new Error("Rewrite pattern must be a RegExp or String");

  replacement = replacement || "";

  return function (conn) {
    var pathname = conn.pathname;

    // Modify the pathname if the pattern matches.
    if (pattern.test(pathname)) conn.location.properties.pathname = conn.basename + pathname.replace(pattern, replacement);

    return conn.call(app);
  };
}

module.exports = rewrite;