nyx_server/core/middleware/ContentStatic.js

Node内容发布

/*!
 * serve-static
 * Copyright(c) 2010 Sencha Inc.
 * Copyright(c) 2011 TJ Holowaychuk
 * Copyright(c) 2014-2015 Douglas Christopher Wilson
 * MIT Licensed
 */

'use strict';

/**
 * Module dependencies.
 * @private
 */

var resolve = require('path').resolve;
var send = require('send');
var url = require('url');

/**
 * Module exports.
 * @public
 */

module.exports = serveStatic;
module.exports.mime = send.mime;


function serveStatic(root, pathFn , options) {
  if (!root) {
    throw new TypeError('root path required');
  }

  if (typeof root !== 'string') {
    throw new TypeError('root path must be a string');
  }

  // copy options object
  var opts = Object.create(options || null);

  // fall-though
  var fallthrough = opts.fallthrough !== false;

  // default redirect
  var redirect = opts.redirect !== false;

  // headers listener
  var setHeaders = opts.setHeaders;

  if (setHeaders && typeof setHeaders !== 'function') {
    throw new TypeError('option setHeaders must be function');
  }

  // setup options for send
  opts.maxage = opts.maxage || opts.maxAge || 0;
  opts.root = resolve(root);


  return function serveStatic(req, res, next) {
    if (req.method !== 'GET' && req.method !== 'HEAD') {
      if (fallthrough) {
        return next();
      }

      // method not allowed
      res.statusCode = 405;
      res.setHeader('Allow', 'GET, HEAD');
      res.setHeader('Content-Length', '0');
      res.end();
      return;
    }

    var forwardError = !fallthrough;
    var path = pathFn(req.originalUrl);

    // make sure redirect occurs at mount
    if (path === '/' && originalUrl.pathname.substr(-1) !== '/') {
        path = '';
    }

    // create send stream
    var stream = send(req, path, opts);

    // add headers listener
    if (setHeaders) {
      stream.on('headers', setHeaders);
    }

    // add file listener for fallthrough
    if (fallthrough) {
      stream.on('file', function onFile() {
        // once file is determined, always forward error
        forwardError = true;
      });
    }

    // forward errors
    stream.on('error', function error(err) {
      if (forwardError || !(err.statusCode < 500)) {
        next(err);
        return;
      };
      next();
    });
    // pipe
    stream.pipe(res);
  };
}