'use strict'; /** * Module dependencies. */ const contentDisposition = require('content-disposition'); const ensureErrorHandler = require('error-inject'); const getType = require('mime-types').contentType; const onFinish = require('on-finished'); const isJSON = require('koa-is-json'); const escape = require('escape-html'); const typeis = require('type-is').is; const statuses = require('statuses'); const destroy = require('destroy'); const assert = require('assert'); const extname = require('path').extname; const vary = require('vary'); const only = require('only'); /** * Prototype. */ module.exports = { /** * Return the request socket. * * @return {Connection} * @api public */ get socket() { return this.ctx.req.socket; }, /** * Return response header. * * @return {Object} * @api public */ get header() { const { res } = this; return typeof res.getHeaders === 'function' ? res.getHeaders() : res._headers || {}; // Node < 7.7 }, /** * Return response header, alias as response.header * * @return {Object} * @api public */ get headers() { return this.header; }, /** * Get response status code. * * @return {Number} * @api public */ get status() { return this.res.statusCode; }, /** * Set response status code. * * @param {Number} code * @api public */ set status(code) { assert('number' == typeof code, 'status code must be a number'); assert(statuses[code], `invalid status code: ${code}`); assert(!this.res.headersSent, 'headers have already been sent'); this._explicitStatus = true; this.res.statusCode = code; if (this.req.httpVersionMajor < 2) this.res.statusMessage = statuses[code]; if (this.body && statuses.empty[code]) this.body = null; }, /** * Get response status message * * @return {String} * @api public */ get message() { return this.res.statusMessage || statuses[this.status]; }, /** * Set response status message * * @param {String} msg * @api public */ set message(msg) { this.res.statusMessage = msg; }, /** * Get response body. * * @return {Mixed} * @api public */ get body() { return this._body; }, /** * Set response body. * * @param {String|Buffer|Object|Stream} val * @api public */ set body(val) { const original = this._body; this._body = val; if (this.res.headersSent) return; // no content if (null == val) { if (!statuses.empty[this.status]) this.status = 204; this.remove('Content-Type'); this.remove('Content-Length'); this.remove('Transfer-Encoding'); return; } // set the status if (!this._explicitStatus) this.status = 200; // set the content-type only if not yet set const setType = !this.header['content-type']; // string if ('string' == typeof val) { if (setType) this.type = /^\s*</.test(val) ? 'html' : 'text'; this.length = Buffer.byteLength(val); return; } // buffer if (Buffer.isBuffer(val)) { if (setType) this.type = 'bin'; this.length = val.length; return; } // stream if ('function' == typeof val.pipe) { onFinish(this.res, destroy.bind(null, val)); ensureErrorHandler(val, err => this.ctx.onerror(err)); // overwriting if (null != original && original != val) this.remove('Content-Length'); if (setType) this.type = 'bin'; return; } // json this.remove('Content-Length'); this.type = 'json'; }, /** * Set Content-Length field to `n`. * * @param {Number} n * @api public */ set length(n) { this.set('Content-Length', n); }, /** * Return parsed response Content-Length when present. * * @return {Number} * @api public */ get length() { const len = this.header['content-length']; const body = this.body; if (null == len) { if (!body) return; if ('string' == typeof body) return Buffer.byteLength(body); if (Buffer.isBuffer(body)) return body.length; if (isJSON(body)) return Buffer.byteLength(JSON.stringify(body)); return; } return ~~len; }, /** * Check if a header has been written to the socket. * * @return {Boolean} * @api public */ get headerSent() { return this.res.headersSent; }, /** * Vary on `field`. * * @param {String} field * @api public */ vary(field) { vary(this.res, field); }, /** * Perform a 302 redirect to `url`. * * The string "back" is special-cased * to provide Referrer support, when Referrer * is not present `alt` or "/" is used. * * Examples: * * this.redirect('back'); * this.redirect('back', '/index.html'); * this.redirect('/login'); * this.redirect('http://google.com'); * * @param {String} url * @param {String} [alt] * @api public */ redirect(url, alt) { // location if ('back' == url) url = this.ctx.get('Referrer') || alt || '/'; this.set('Location', url); // status if (!statuses.redirect[this.status]) this.status = 302; // html if (this.ctx.accepts('html')) { url = escape(url); this.type = 'text/html; charset=utf-8'; this.body = `Redirecting to <a href="${url}">${url}</a>.`; return; } // text this.type = 'text/plain; charset=utf-8'; this.body = `Redirecting to ${url}.`; }, /** * Set Content-Disposition header to "attachment" with optional `filename`. * * @param {String} filename * @api public */ attachment(filename) { if (filename) this.type = extname(filename); this.set('Content-Disposition', contentDisposition(filename)); }, /** * Set Content-Type response header with `type` through `mime.lookup()` * when it does not contain a charset. * * Examples: * * this.type = '.html'; * this.type = 'html'; * this.type = 'json'; * this.type = 'application/json'; * this.type = 'png'; * * @param {String} type * @api public */ set type(type) { type = getType(type); if (type) { this.set('Content-Type', type); } else { this.remove('Content-Type'); } }, /** * Set the Last-Modified date using a string or a Date. * * this.response.lastModified = new Date(); * this.response.lastModified = '2013-09-13'; * * @param {String|Date} type * @api public */ set lastModified(val) { if ('string' == typeof val) val = new Date(val); this.set('Last-Modified', val.toUTCString()); }, /** * Get the Last-Modified date in Date form, if it exists. * * @return {Date} * @api public */ get lastModified() { const date = this.get('last-modified'); if (date) return new Date(date); }, /** * Set the ETag of a response. * This will normalize the quotes if necessary. * * this.response.etag = 'md5hashsum'; * this.response.etag = '"md5hashsum"'; * this.response.etag = 'W/"123456789"'; * * @param {String} etag * @api public */ set etag(val) { if (!/^(W\/)?"/.test(val)) val = `"${val}"`; this.set('ETag', val); }, /** * Get the ETag of a response. * * @return {String} * @api public */ get etag() { return this.get('ETag'); }, /** * Return the response mime type void of * parameters such as "charset". * * @return {String} * @api public */ get type() { const type = this.get('Content-Type'); if (!type) return ''; return type.split(';')[0]; }, /** * Check whether the response is one of the listed types. * Pretty much the same as `this.request.is()`. * * @param {String|Array} types... * @return {String|false} * @api public */ is(types) { const type = this.type; if (!types) return type || false; if (!Array.isArray(types)) types = [].slice.call(arguments); return typeis(type, types); }, /** * Return response header. * * Examples: * * this.get('Content-Type'); * // => "text/plain" * * this.get('content-type'); * // => "text/plain" * * @param {String} field * @return {String} * @api public */ get(field) { return this.header[field.toLowerCase()] || ''; }, /** * Set header `field` to `val`, or pass * an object of header fields. * * Examples: * * this.set('Foo', ['bar', 'baz']); * this.set('Accept', 'application/json'); * this.set({ Accept: 'text/plain', 'X-API-Key': 'tobi' }); * * @param {String|Object|Array} field * @param {String} val * @api public */ set(field, val) { if (2 == arguments.length) { if (Array.isArray(val)) val = val.map(String); else val = String(val); this.res.setHeader(field, val); } else { for (const key in field) { this.set(key, field[key]); } } }, /** * Append additional header `field` with value `val`. * * Examples: * * ``` * this.append('Link', ['<http://localhost/>', '<http://localhost:3000/>']); * this.append('Set-Cookie', 'foo=bar; Path=/; HttpOnly'); * this.append('Warning', '199 Miscellaneous warning'); * ``` * * @param {String} field * @param {String|Array} val * @api public */ append(field, val) { const prev = this.get(field); if (prev) { val = Array.isArray(prev) ? prev.concat(val) : [prev].concat(val); } return this.set(field, val); }, /** * Remove header `field`. * * @param {String} name * @api public */ remove(field) { this.res.removeHeader(field); }, /** * Checks if the request is writable. * Tests for the existence of the socket * as node sometimes does not set it. * * @return {Boolean} * @api private */ get writable() { // can't write any more after response finished if (this.res.finished) return false; const socket = this.res.socket; // There are already pending outgoing res, but still writable // https://github.com/nodejs/node/blob/v4.4.7/lib/_http_server.js#L486 if (!socket) return true; return socket.writable; }, /** * Inspect implementation. * * @return {Object} * @api public */ inspect() { if (!this.res) return; const o = this.toJSON(); o.body = this.body; return o; }, /** * Return JSON representation. * * @return {Object} * @api public */ toJSON() { return only(this, [ 'status', 'message', 'header' ]); }, /** * Flush any set headers, and begin the body */ flushHeaders() { this.res.flushHeaders(); } };