Cross origin requests are only supported for HTTP

问题:

I\'m using this code to make an AJAX request:

$(\"#userBarSignup\").click(function(){
    $.get(\"C:/xampp/htdocs/webname/resources/templates/signup.php\",
        {/*params*/},
        function(response){
            $(\"#signup\").html(\"TEST\");
            $(\"#signup\").html(response);
        },
        \"html\");

But from the Google Chrome JavaScript console I keep receiving this error:

XMLHttpRequest cannot load file:///C:/xampp/htdocs/webname/resources/templates/signup.php. Cross origin requests are only supported for HTTP.

The problem is that the signup.php file is hosted on my local web server that\'s where all the website is run from so it\'s not cross-domain.

How can I solve this problem?

回答1:

You need to actually run a webserver, and make the get request to a URI on that server, rather than making the get request to a file; e.g. change the line:

    $.get(\"C:/xampp/htdocs/webname/resources/templates/signup.php\",

to read something like:

    $.get(\"http://localhost/resources/templates/signup.php\",

and the initial request page needs to be made over http as well.

回答2:

I\'ve had luck starting chrome with the following switch:

--allow-file-access-from-files

On os x try (re-type the dashes if you copy paste):

open -a \'Google Chrome\' --args -allow-file-access-from-files

On other *nix run (not tested)

 google-chrome  --allow-file-access-from-files

or on windows edit the properties of the chrome shortcut and add the switch, e.g.

 C:\\ ... \\Application\\chrome.exe --allow-file-access-from-files

to the end of the \"target\" path

回答3:

If you’re working on a little front-end project and want to test it locally, you’d typically open it by pointing your local directory in the web browser, for instance entering file:///home/erick/mysuperproject/index.html in your URL bar. However, if your site is trying to load resources, even if they’re placed in your local directory, you might see warnings like this:

XMLHttpRequest cannot load file:///home/erick/mysuperproject/mylibrary.js. Cross origin requests are only supported for HTTP.

Chrome and other modern browsers have implemented security restrictions for Cross Origin Requests, which means that you cannot load anything through file:/// , you need to use http:// protocol at all times, even locally -due Same Origin policies. Simple as that, you’d need to mount a webserver to run your project there.

This is not the end of the world and there are many solutions out there, including the good old Apache (with VirtualHosts if you’re running several other projects), node.js with express, a Ruby server, etc. or simply modifying your browser settings.

However there’s a simpler and lightweight solution for the lazy ones. You can use Python’s SimpleHTTPServer. It comes already bundled with python so you don’t need to install or configure anything at all!

So cd to your project directory, for instance

1 cd /home/erick/mysuperproject and then simply use

1 python -m SimpleHTTPServer And that’s it, you’ll see this message in your terminal

1 Serving HTTP on 0.0.0.0 port 8000 ... So now you can go back to your browser and visit http://0.0.0.0:8000 with all your directory files served there. You can configure the port and other things, just see the documentation. But this simply trick works for me when I’m in a rush to test a new library or work out a new idea.

There you go, happy coding!

EDIT: In Python 3+, SimpleHTTPServer has been replaced with http.server. So In Python 3.3, for example, the following command is equivalent:

python -m http.server 8000

回答4:

I was getting the same error while trying to load simply HTML files that used JSON data to populate the page, so I used used node.js and express to solve the problem. If you do not have node installed, you need to install node first.

1. Install express npm install express

2. Create a server.js file in the root folder of your project, in my case one folder above the files I wanted to server

3. Put something like the following in the server.js file and read about this on the express gihub site:

   var express = require(\'express\');
   var app = express();
   var path = require(\'path\');
   
   // __dirname will use the current path from where you run this file 
   app.use(express.static(__dirname));
   app.use(express.static(path.join(__dirname, \'/FOLDERTOHTMLFILESTOSERVER\')));
   
   app.listen(8000);
   console.log(\'Listening on port 8000\');
   

4. After you\'ve saved server.js, you can run the server using:

node server.js

1. Go to http://localhost:8000/FILENAME and you should see the HTML file you were trying to load

回答5:

It works best this way. Make sure that both files are on the server. When calling the html page, make use of the web address like: http:://localhost/myhtmlfile.html, and not, C::///users/myhtmlfile.html. Make usre as well that the url passed to the json is a web address as denoted below:

$(function(){
                $(\'#typeahead\').typeahead({
                    source: function(query, process){
                        $.ajax({
                            url: \'http://localhost:2222/bootstrap/source.php\',
                            type: \'POST\',
                            data: \'query=\' +query,
                            dataType: \'JSON\',
                            async: true,
                            success: function(data){
                                process(data);
                            }
                        });
                    }
                });
            });

回答6:

If you have nodejs installed, you can download and install the server using command line:

npm install -g http-server

Change directories to the directory where you want to serve files from:

$ cd ~/projects/angular/current_project 

Run the server:

$ http-server 

which will produce the message Starting up http-server, serving on:

Available on: http://your_ip:8080 and http://127.0.0.1:8080

That allows you to use urls in your browser like

http://your_ip:8080/index.html