Grunt connect task and middleware Access-Control-Allow-Origin

问题

I would like to allow access to cross origin calls which I need to be able to perform rest API calls to the server.

My connect grunt task is configured as follows:

    connect: {
  options: {
    port: 9000,
    // Change this to '0.0.0.0' to access the server from outside.
    hostname: 'localhost',
    livereload: 35729,
    middleware: function(connect, options, next) {
      return [
        function(req, res, next) {
          res.setHeader('Access-Control-Allow-Origin', '*');
          res.setHeader('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
          res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
          next();
        }
      ];
    }
  },
},

When I run the grunt server I am getting Cannot GET /. Without the middleware configuration the app is working and the index file is loaded correctly.

Could you guide me to what I am doing wrong or missing out?

Some more details about my gruntfile is that I am using the yeoman angular seed app as my base to the app.

回答1:

Try something like this:

connect: {
  options: {
    port: 9000,
    // Change this to '0.0.0.0' to access the server from outside.
    hostname: 'localhost',
    livereload: 35729,

    // remove next from params
    middleware: function(connect, options) {
      return [
        function(req, res, next) {
          res.setHeader('Access-Control-Allow-Origin', '*');
          res.setHeader('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
          res.setHeader('Access-Control-Allow-Headers', 'Content-Type');

          // don't just call next() return it
          return next();
        },

        // add other middlewares here 
        connect.static(require('path').resolve('.'))

      ];
    }
    },
    },

回答2:

Nod to bpaul, who set me on the path to correct answer. The format of a response to a similar question will work here.

Replace 'next' with middlewares, and push your anonymous function into the middleware array before returning it:

middleware: function(connect, options, middlewares) {

    middlewares.unshift(function(req, res, next) {
        res.setHeader('Access-Control-Allow-Credentials', true);
        res.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
        res.setHeader('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS');
        next();
    });

    return middlewares;
}

回答3:

connect: {
  options: {
    port: 9000,
    // Change this to '0.0.0.0' to access the server from outside.
    hostname: 'localhost',
    livereload: 35729,
    middleware: function(connect, options, next) {
      return [
        function(req, res, next) {
         res.header('Access-Control-Allow-Credentials', true);
         res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
         res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS');
         next();
      }];
     }
   };

this will helps you in getting the get call Access-Control-Allow-Credentials

回答4:

Grunt connect comes with multiple middlewares, stored as functions in an array. When you set middleware by returning an array, you override the existing middleware responsible for serving your pages.

Going off ansorensen's comment of the documentation, https://github.com/gruntjs/grunt-contrib-connect#middleware the relevant section being.

options: {
    middleware: function(connect, options, middlewares) {
      // inject a custom middleware into the array of default middlewares
      middlewares.unshift(function(req, res, next) {
        if (req.url !== '/hello/world') return next();

        res.end('Hello, world from port #' + options.port + '!');
      });

      return middlewares;
    },
},

Middleware earlier in the array take effect before those later in the array.

So what you would want is

connect: {
    options: {
        port: 9000,
        // Change this to '0.0.0.0' to access the server from outside.
        hostname: 'localhost',
        livereload: 35729,

        // remove next from params
        middleware: function(connect, options, middlewares) {
            middlewares.unshift(function(req, res, next) {
                res.setHeader('Access-Control-Allow-Origin', '*');
                res.setHeader('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
                res.setHeader('Access-Control-Allow-Headers', 'Content-Type');

                return next();
            });

            return middlewares;
        }
    },
},

来源：https://stackoverflow.com/questions/21581258/grunt-connect-task-and-middleware-access-control-allow-origin