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diff --git a/backend/node_modules/cors/README.md b/backend/node_modules/cors/README.md new file mode 100644 index 0000000..732b847 --- /dev/null +++ b/backend/node_modules/cors/README.md @@ -0,0 +1,243 @@ +# cors + +[![NPM Version][npm-image]][npm-url] +[![NPM Downloads][downloads-image]][downloads-url] +[![Build Status][travis-image]][travis-url] +[![Test Coverage][coveralls-image]][coveralls-url] + +CORS is a node.js package for providing a [Connect](http://www.senchalabs.org/connect/)/[Express](http://expressjs.com/) middleware that can be used to enable [CORS](http://en.wikipedia.org/wiki/Cross-origin_resource_sharing) with various options. + +**[Follow me (@troygoode) on Twitter!](https://twitter.com/intent/user?screen_name=troygoode)** + +* [Installation](#installation) +* [Usage](#usage) + * [Simple Usage](#simple-usage-enable-all-cors-requests) + * [Enable CORS for a Single Route](#enable-cors-for-a-single-route) + * [Configuring CORS](#configuring-cors) + * [Configuring CORS Asynchronously](#configuring-cors-asynchronously) + * [Enabling CORS Pre-Flight](#enabling-cors-pre-flight) +* [Configuration Options](#configuration-options) +* [Demo](#demo) +* [License](#license) +* [Author](#author) + +## Installation + +This is a [Node.js](https://nodejs.org/en/) module available through the +[npm registry](https://www.npmjs.com/). Installation is done using the +[`npm install` command](https://docs.npmjs.com/getting-started/installing-npm-packages-locally): + +```sh +$ npm install cors +``` + +## Usage + +### Simple Usage (Enable *All* CORS Requests) + +```javascript +var express = require('express') +var cors = require('cors') +var app = express() + +app.use(cors()) + +app.get('/products/:id', function (req, res, next) { + res.json({msg: 'This is CORS-enabled for all origins!'}) +}) + +app.listen(80, function () { + console.log('CORS-enabled web server listening on port 80') +}) +``` + +### Enable CORS for a Single Route + +```javascript +var express = require('express') +var cors = require('cors') +var app = express() + +app.get('/products/:id', cors(), function (req, res, next) { + res.json({msg: 'This is CORS-enabled for a Single Route'}) +}) + +app.listen(80, function () { + console.log('CORS-enabled web server listening on port 80') +}) +``` + +### Configuring CORS + +```javascript +var express = require('express') +var cors = require('cors') +var app = express() + +var corsOptions = { + origin: 'http://example.com', + optionsSuccessStatus: 200 // some legacy browsers (IE11, various SmartTVs) choke on 204 +} + +app.get('/products/:id', cors(corsOptions), function (req, res, next) { + res.json({msg: 'This is CORS-enabled for only example.com.'}) +}) + +app.listen(80, function () { + console.log('CORS-enabled web server listening on port 80') +}) +``` + +### Configuring CORS w/ Dynamic Origin + +```javascript +var express = require('express') +var cors = require('cors') +var app = express() + +var whitelist = ['http://example1.com', 'http://example2.com'] +var corsOptions = { + origin: function (origin, callback) { + if (whitelist.indexOf(origin) !== -1) { + callback(null, true) + } else { + callback(new Error('Not allowed by CORS')) + } + } +} + +app.get('/products/:id', cors(corsOptions), function (req, res, next) { + res.json({msg: 'This is CORS-enabled for a whitelisted domain.'}) +}) + +app.listen(80, function () { + console.log('CORS-enabled web server listening on port 80') +}) +``` + +If you do not want to block REST tools or server-to-server requests, +add a `!origin` check in the origin function like so: + +```javascript +var corsOptions = { + origin: function (origin, callback) { + if (whitelist.indexOf(origin) !== -1 || !origin) { + callback(null, true) + } else { + callback(new Error('Not allowed by CORS')) + } + } +} +``` + +### Enabling CORS Pre-Flight + +Certain CORS requests are considered 'complex' and require an initial +`OPTIONS` request (called the "pre-flight request"). An example of a +'complex' CORS request is one that uses an HTTP verb other than +GET/HEAD/POST (such as DELETE) or that uses custom headers. To enable +pre-flighting, you must add a new OPTIONS handler for the route you want +to support: + +```javascript +var express = require('express') +var cors = require('cors') +var app = express() + +app.options('/products/:id', cors()) // enable pre-flight request for DELETE request +app.del('/products/:id', cors(), function (req, res, next) { + res.json({msg: 'This is CORS-enabled for all origins!'}) +}) + +app.listen(80, function () { + console.log('CORS-enabled web server listening on port 80') +}) +``` + +You can also enable pre-flight across-the-board like so: + +```javascript +app.options('*', cors()) // include before other routes +``` + +### Configuring CORS Asynchronously + +```javascript +var express = require('express') +var cors = require('cors') +var app = express() + +var whitelist = ['http://example1.com', 'http://example2.com'] +var corsOptionsDelegate = function (req, callback) { + var corsOptions; + if (whitelist.indexOf(req.header('Origin')) !== -1) { + corsOptions = { origin: true } // reflect (enable) the requested origin in the CORS response + } else { + corsOptions = { origin: false } // disable CORS for this request + } + callback(null, corsOptions) // callback expects two parameters: error and options +} + +app.get('/products/:id', cors(corsOptionsDelegate), function (req, res, next) { + res.json({msg: 'This is CORS-enabled for a whitelisted domain.'}) +}) + +app.listen(80, function () { + console.log('CORS-enabled web server listening on port 80') +}) +``` + +## Configuration Options + +* `origin`: Configures the **Access-Control-Allow-Origin** CORS header. Possible values: + - `Boolean` - set `origin` to `true` to reflect the [request origin](http://tools.ietf.org/html/draft-abarth-origin-09), as defined by `req.header('Origin')`, or set it to `false` to disable CORS. + - `String` - set `origin` to a specific origin. For example if you set it to `"http://example.com"` only requests from "http://example.com" will be allowed. + - `RegExp` - set `origin` to a regular expression pattern which will be used to test the request origin. If it's a match, the request origin will be reflected. For example the pattern `/example\.com$/` will reflect any request that is coming from an origin ending with "example.com". + - `Array` - set `origin` to an array of valid origins. Each origin can be a `String` or a `RegExp`. For example `["http://example1.com", /\.example2\.com$/]` will accept any request from "http://example1.com" or from a subdomain of "example2.com". + - `Function` - set `origin` to a function implementing some custom logic. The function takes the request origin as the first parameter and a callback (which expects the signature `err [object], allow [bool]`) as the second. +* `methods`: Configures the **Access-Control-Allow-Methods** CORS header. Expects a comma-delimited string (ex: 'GET,PUT,POST') or an array (ex: `['GET', 'PUT', 'POST']`). +* `allowedHeaders`: Configures the **Access-Control-Allow-Headers** CORS header. Expects a comma-delimited string (ex: 'Content-Type,Authorization') or an array (ex: `['Content-Type', 'Authorization']`). If not specified, defaults to reflecting the headers specified in the request's **Access-Control-Request-Headers** header. +* `exposedHeaders`: Configures the **Access-Control-Expose-Headers** CORS header. Expects a comma-delimited string (ex: 'Content-Range,X-Content-Range') or an array (ex: `['Content-Range', 'X-Content-Range']`). If not specified, no custom headers are exposed. +* `credentials`: Configures the **Access-Control-Allow-Credentials** CORS header. Set to `true` to pass the header, otherwise it is omitted. +* `maxAge`: Configures the **Access-Control-Max-Age** CORS header. Set to an integer to pass the header, otherwise it is omitted. +* `preflightContinue`: Pass the CORS preflight response to the next handler. +* `optionsSuccessStatus`: Provides a status code to use for successful `OPTIONS` requests, since some legacy browsers (IE11, various SmartTVs) choke on `204`. + +The default configuration is the equivalent of: + +```json +{ + "origin": "*", + "methods": "GET,HEAD,PUT,PATCH,POST,DELETE", + "preflightContinue": false, + "optionsSuccessStatus": 204 +} +``` + +For details on the effect of each CORS header, read [this](http://www.html5rocks.com/en/tutorials/cors/) article on HTML5 Rocks. + +## Demo + +A demo that illustrates CORS working (and not working) using jQuery is available here: [http://node-cors-client.herokuapp.com/](http://node-cors-client.herokuapp.com/) + +Code for that demo can be found here: + +* Client: [https://github.com/TroyGoode/node-cors-client](https://github.com/TroyGoode/node-cors-client) +* Server: [https://github.com/TroyGoode/node-cors-server](https://github.com/TroyGoode/node-cors-server) + +## License + +[MIT License](http://www.opensource.org/licenses/mit-license.php) + +## Author + +[Troy Goode](https://github.com/TroyGoode) ([troygoode@gmail.com](mailto:troygoode@gmail.com)) + +[coveralls-image]: https://img.shields.io/coveralls/expressjs/cors/master.svg +[coveralls-url]: https://coveralls.io/r/expressjs/cors?branch=master +[downloads-image]: https://img.shields.io/npm/dm/cors.svg +[downloads-url]: https://npmjs.org/package/cors +[npm-image]: https://img.shields.io/npm/v/cors.svg +[npm-url]: https://npmjs.org/package/cors +[travis-image]: https://img.shields.io/travis/expressjs/cors/master.svg +[travis-url]: https://travis-ci.org/expressjs/cors |