For instances where running a local webserver is not an option, you can allow Chrome access to file:// files via a browser switch. After some digging, I found this discussion, which mentions a browser switch in opening post. Run your Chrome instance with: chrome.exe –allow-file-access-from-files This may be acceptable for development environments, but little else. … Read more
An actual JSON request would look like this: data: ‘{“command”:”on”}’, Where you’re sending an actual JSON string. For a more general solution, use JSON.stringify() to serialize an object to JSON, like this: data: JSON.stringify({ “command”: “on” }), To support older browsers that don’t have the JSON object, use json2.js which will add it in. What’s … Read more
Handling CORS requests properly is a tad more involved. Here is a function that will respond more fully (and properly). /** * An example CORS-compliant method. It will allow any GET, POST, or OPTIONS requests from any * origin. * * In a production environment, you probably want to be more restrictive, but this gives … Read more
I’m assuming you know how to make a native XHR request (you can brush up here and here) Since any browser that supports native promises will also support xhr.onload, we can skip all the onReadyStateChange tomfoolery. Let’s take a step back and start with a basic XHR request function using callbacks: function makeRequest (method, url, … Read more
Chrome : In the Network panel of devtools, right-click and select Copy as cURL Paste / Edit the request, and then send it from a terminal, assuming you have the curl command See capture : Alternatively, and in case you need to send the request in the context of a webpage, select “Copy as fetch” … Read more
You can get it by XMLHttpRequest.responseText in XMLHttpRequest.onreadystatechange when XMLHttpRequest.readyState equals to XMLHttpRequest.DONE. Here’s an example (not compatible with IE6/7). var xhr = new XMLHttpRequest(); xhr.onreadystatechange = function() { if (xhr.readyState == XMLHttpRequest.DONE) { alert(xhr.responseText); } } xhr.open(‘GET’, ‘http://example.com’, true); xhr.send(null); For better crossbrowser compatibility, not only with IE6/7, but also to cover some browser-specific … Read more
There are a few things that you can do with fetch and not with XHR: You can use the Cache API with the request and response objects; You can perform no-cors requests, getting a response from a server that doesn’t implement CORS. You can’t access the response body directly from JavaScript, but you can use … Read more
Chrome does not support localhost for CORS requests (a bug opened in 2010, marked WontFix in 2014). To get around this you can use a domain like localho.st (which points at 127.0.0.1 just like localhost) or start chrome with the –disable-web-security flag (assuming you’re just testing).
You can send it and insert the data to the body: var xhr = new XMLHttpRequest(); xhr.open(“POST”, yourUrl, true); xhr.setRequestHeader(‘Content-Type’, ‘application/json’); xhr.send(JSON.stringify({ value: value })); By the way, for get request: var xhr = new XMLHttpRequest(); // we defined the xhr xhr.onreadystatechange = function () { if (this.readyState != 4) return; if (this.status == 200) … Read more
According to MDN, Preflighted requests Unlike simple requests (discussed above), “preflighted” requests first send an HTTP OPTIONS request header to the resource on the other domain, in order to determine whether the actual request is safe to send. Cross-site requests are preflighted like this since they may have implications to user data. In particular, a … Read more