React Js: Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0
Add two headers Content-Type and Accept to be equal to application/json.
Add two headers Content-Type and Accept to be equal to application/json.
What you saw in Firefox was not the actual request; note that the HTTP method is OPTIONS, not POST. It was actually the ‘pre-flight’ request that the browser makes to determine whether a cross-domain AJAX request should be allowed: http://www.w3.org/TR/cors/ The Access-Control-Request-Headers header in the pre-flight request includes the list of headers in the actual … Read more
Your server is not returning a content-type, so Firefox assumes that since this is _XML_HttpRequest your response might be XML and tries to parse it. When that fails, it stops trying and reports that this wasn’t XML after all. Chrome likely does the same but doesn’t report anything. I suggest actually sending a Content-Type header … Read more
Close chrome (or chromium) and restart with the –disable-web-security argument. I just tested this and verified that I can access the contents of an iframe with src=”http://google.com” embedded in a page served from “localhost” (tested under chromium 5 / ubuntu). For me the exact command was: Note : Kill all chrome instances before running command The browser … Read more
Neither of the answers here helped me. The problem was: I was using the slim build of jQuery, which had some things removed, ajax being one of them. The solution: Just download the regular (compressed or not) version of jQuery here and include it in your project.
JSONP is really a simply trick to overcome XMLHttpRequest same domain policy. (As you know one cannot send AJAX (XMLHttpRequest) request to a different domain.) So – instead of using XMLHttpRequest we have to use script HTMLl tags, the ones you usually use to load JS files, in order for JS to get data from another domain. Sounds weird? Thing is – turns out script tags … Read more
I’m assuming that you are using JQuery? If so, then the correct method is: JavaScript is case sensitive.
The response you’re getting is actually correct. Per the docs, Firebase returns a 200 status code and an empty response. net::ERR_EMPTY_RESPONSE is exactly that. What you should do is check for both null and a 200 status code in the response; if true, you can safely assume that the post was deleted. My personal opinion is that Firebase should really consider returning something more … Read more
You mentioned using json2.js to stringify your data, but the POSTed data appears to be URLEncoded JSON You may have already seen it, but this post about the invalid JSON primitive covers why the JSON is being URLEncoded. I’d advise against passing a raw, manually-serialized JSON string into your method. ASP.NET is going to automatically JSON deserialize the request’s POST … Read more
I would say it is easier to use jQuery.ajax: jQuery is a great tool with lots of examples and plugins that allow you to do some pretty amazing things!