I have created a php script that I know works. I try communication to it with the following ajax call:
var request = new XMLHttpRequest();
request.open("GET", "http://larsbak.dk/schedule/GET/schedule.php");
request.setRequestHeader("Content-type", "application/json");
request.onreadystatechange = function () {
if (request.readyState == 4 && request.status == 200) {
data = JSON.parse(request.responseText);
}
request.send("id=201303560&interval=100000");
When i use the above script the server respons with error with error 104, which means that id parameter is not set. Why is this happening?
You are making a GET request, so you can't have a request body. Change that to "POST" or move the data to the query string.
You are claiming you are sending "application/json", which "id=201303560&interval=100000" is not. You are sending "application/www-x-form-urlencoded" data.
You forgot to end (}) your onreadystatechange handler
Related
I am trying to sync both client-side and server-side scripts that the client intakes a value from the textbox and sends it to the server, upon which the server displays that input as a cookie.
Here is the code that I have so far
function loadCookie() {
//[1] make a new request object
var xhttp = new XMLHttpRequest();
//[2] set the request options
xhttp.open("GET", "index.html", true);
//[3] define what you will do when you ge a response (callback)
xhttp.onreadystatechange = function(){
if (this.readyState == 4 && this.status == 200) {
document.getElementById("input_response").innerHTML = this.responseText;
}
};
//[4] finally send out the request
xhttp.send();
}
I have the and the button but I am having issue of the page re-loading itself instead of taking the value of the input and showing it as a cookie in the server. I'm suspecting it is having to do with the URL by the index.html
I am trying to upload a file to the REST Api of Octoprint, which should be done by sending a POST request with Content-Type: multipart/form-data
(http://docs.octoprint.org/en/master/api/fileops.html#upload-file)
I am using NodeJS and two libraries, XmlHttpRequest and form-data. When trying:
var xhr = new xmlhttprequest() ;
var form = new formData() ;
form.append('exampleKey', 'exampleValue');
xhr.open("POST","octopi.local/api/local", true) ;
xhr.setRequestHeader("Content-Type","multipart/form-data") ;
xhr.send(form) ;
I get an error at the xhr.send line :
TypeError: first argument must be a string or Buffer
If I make a synchronous request by using xhr.open("POST",url,false), this error disappears.
Why is it so ? Is there a way to turn it into an asynchronous request ?
EDIT Actually, I don't really understand the documentation. I suppose that I should set the file I want to upload by using form.append("filename", filepath, "exampleName"), but I am not sure about that. The fact is that I noticed that I get the TypeError even if I try a simplified request, without sending any file.
EDIT2 This is the modified code, which returns the same error :
var XMLHttpRequest=require('xmlhttprequest').XMLHttpRequest ;
var FormData = require('form-data');
var data = new FormData();
data.append("key","value" );
var xhr = new XMLHttpRequest();
xhr.open('POST', "octopi.local/api/files/");
xhr.send(data);
After a long time working on this, I finally managed to upload a file. If you use NodeJS, don't rely on the MDN documentation: it tells what the libraries should do, not what they can actually do on the node platform. You should only focus on the docs available on GitHub.
It seems that it is not currently possible to send a form with XMLHttpRequest : I tried using JSON.stringify(form) but then wireshark tells me that the request is not a multipart/formdata request.
If you want to upload a file, you should rather use the 'request' module. The following has worked for me :
exports.unwrappeduploadToOctoprint = function(){
"use strict" ;
var form ={
file: {
value: fs.readFileSync(__dirname+'/test2.gcode'),
options: { filename: 'test2.gcode'}
}
};
var options = {
method: 'POST',
url: 'http://192.168.1.24/api/files/local',
headers: { 'x-api-key': 'E0A2518FB11B40F595FC0068192A1AB3'},
formData: form
};
var req = request(options, function (error, response, body) {
if (error) throw new Error(error);
console.log(body);
});
};
Seems that you have some typos in your code. Use code snippet below instead. Replace the relevant parts according to your needs
var fileToUpload = document.getElementById('input').files[0];
var data = new FormData();
data.append("myfile", fileToUpload);
var xhr = new XMLHttpRequest();
xhr.open('POST', "upload_endpoint");
xhr.send(data);
This servlet code,here 1st i want to send return message(if message!=null) to the Ajax for alert and 2nd one if message==null i want to call another jsp with pass the list to this jsp.
if(message!=null){
response.setContentType("text/plain");
response.getWriter().write(message);
}else{
JSONObject jobj = new JSONObject();
String urlToRedirect = "SearchEmployee.jsp";
jobj.put("url",urlToRedirect );
response.getWriter().write(jobj.toString());
}
Here i cant understand how to call this jsp url in else part
$.ajax({
type:"POST",
url:'../SearchEmployeeServlet',
data:$('#DisplayEmployeeListForm').serialize(),//$('form').serialize();
success:function(msg){
if(msg!=""){
alert(msg);
window.location.reload(true);
}else{
....here i want to call 2nd jsp
}
}
});
You could just forward the request server-side, to avoid needing the client to make a second request:
request.getRequestDispatcher("SearchEmployee.jsp").forward(request, response);
Or alternatively, you could send an HTTP redirect response, so the client should handle the redirection to the second request automatically:
response.sendRedirect(response.encodeRedirectUrl("SearchEmployee.jsp"));
Note that how you handle this in the JavaScript depends on the datatype you expect to receive from SearchEmployee.jsp. For example, if it is XML and you have set the response content-type to text/xml jQuery will parse it and pass you an XML DOM object to your success function:
success:function(msg) {
if (msg instanceof XMLDocument) {
// handle list
} else {
alert(msg);
window.location.reload(true);
}
}
If you're expecting HTML, this may be returned as a string, so you could test to see if your returned string starts with some HTML. For example, if your HTML will always start with a <ul> tag:
success:function(msg) {
if (msg.startsWith("<ul>")) { // note you may need to do msg = $.trim(msg) first
// handle list
} else {
alert(msg);
window.location.reload(true);
}
}
If you don't want to auto-forward as suggested above and you'd rather stick with your current approach, there are a few things you'll need to change.
Using if(msg!="") in your success function is bad as that will return true as long as the server does not return an empty response (so in both cases you'll get an alert).
The first thing to do is to add a content-type header to your servlet code to indicate you're returning JSON in the second case:
response.setContentType("application/json");
response.getWriter().write(jobj.toString());
Now when jQuery handles the response, it will attempt to parse it as JSON before calling the success function. As such, you can now test in your success function whether the argument jQuery has given you is an object or a string:
success:function(msg){
if (typeof msg === "object") {
// you got the JSON response
$.ajax({
url: msg.url,
// etc...
});
} else {
// you got the plain text response
alert(msg);
window.location.reload(true);
}
}
Just make the ajax request in else part as you did above.
$.ajax({url: "jsp url", success: function(result){
}});
Find more information here
We're running an external Grails server-application with the Spring Security plugin.
The front-end is running locally on AngularJS.
Whenever I try to login, the request is immediately canceled.. Remarkably AngularJS sends a GET request first with the OPTIONS method; this returns a 200 OK response just fine.
The actual POST request does never reach the server though... what could possibly cancel my request?
The following code:
$scope.login = function() {
$http.defaults.headers.common["X-Requested-With"] = "XMLHttpRequest";
$scope.loggingIn = true;
// Setup Config
var data = {
j_username: $scope.user.email,
j_password: $scope.user.password
}
var config = {method: 'POST', url: serverUri+'/j_spring_security_check/', data: data};
// Dispatch HTTP Request
$http(config)
.success(function(data, status, headers, config) {
if (data.status) {
// successful login
User.isLogged = true;
User.username = data.username;
}
else {
User.isLogged = false;
User.username = '';
}
$scope.loggingIn = false;
console.log("NOICE!");
})
.error(function(data, status, headers, config) {
$scope.loggingIn = false;
User.isLogged = false;
User.username = '';
if (status == 0) {
// Request got cancelled
console.log("Request got cancelled.");
return;
}
});
}
This is what the canceled request looks like: http://i.stack.imgur.com/kiWnb.png
This is what the OPTIONS request looks like: http://i.stack.imgur.com/FAj96.png
Apparently Chrome does not handle 302 Moved temporarily status codes efficiently when queried by AngularJS in my situation. Firefox properly shows there is a response where Chrome just shows the request as canceled with no response information whatsoever.
This question is solved, but there is still a mystery as to WHY AngularJS does not work. See my question here:
AngularJS $http ajax does not follow Location header
I am wondering what is the best way to stop duplciate submissions when using jquery and ajax?
I come up with 2 possible ways but not sure if these are the only 2.
On Ajax start disable all buttons till request is done. 2 problems I see with this though is I use jquery model dialog so I don't know how easy it would be to disable those button as I not sure if they have id's. Second I if the the request hangs the user has really no way to try again since all the buttons are disabled.
I am looking into something called AjaxQueue at this time I have no clue if it is what I need or how it works since the site where the plugin is apparently down for maintenance.
http://docs.jquery.com/AjaxQueue
Edit
I think this is a spin off of what I was looking at.
http://www.protofunc.com/scripts/jquery/ajaxManager/
The only problem I see with this ajaxManager is that I think I have to change all my $.post, $.get and $.ajax ones to their type.
But what happens if I need a special parameter from $.ajax? Or that fact I like using .post and .get.
Edit 2
I think it can take in all $.ajax options. I am still looking into it. However what I am unsure about now is can I use the same constructor for all requests that will use the same options.
First you have to construct/configure a new Ajaxmanager
//create an ajaxmanager named someAjaxProfileName
var someManagedAjax = $.manageAjax.create('someAjaxProfileName', {
queue: true,
cacheResponse: true
});
Or do I have to make the above every single time?
How about setting a flag when the user clicks the button? You will only clear the flag when the AJAX request completes successfully (in complete, which is called after the success and error callbacks), and you will only send an AJAX request if the flag is not set.
Related to AJAX queuing there is a plugin called jQuery Message Queuing that is very good. I've used it myself.
var requestSent = false;
jQuery("#buttonID").click(function() {
if(!requestSent) {
requestSent = true;
jQuery.ajax({
url: "http://example.com",
....,
timeout: timeoutValue,
complete: function() {
...
requestSent = false;
},
});
}
});
You can set a timeout value for long-running requests (value is in milliseconds) if you think your request has a possibility of hanging. If an timeout occurs, the error callback is called, after which the complete callback gets called.
You could store an active request in a variable, then clear it when there's a response.
var request; // Stores the XMLHTTPRequest object
$('#myButton').click(function() {
if(!request) { // Only send the AJAX request if there's no current request
request = $.ajax({ // Assign the XMLHTTPRequest object to the variable
url:...,
...,
complete: function() { request = null } // Clear variable after response
});
}
});
EDIT:
One nice thing about this, is that you could cancel long running requests using abort().
var request; // Stores the XMLHTTPRequest object
var timeout; // Stores timeout reference for long running requests
$('#myButton').click(function() {
if(!request) { // Only send the AJAX request if there's no current request
request = $.ajax({ // Assign the XMLHTTPRequest object to the variable
url:...,
...,
complete: function() { timeout = request = null } // Clear variables after response
});
timeout = setTimeout( function() {
if(request) request.abort(); // abort request
}, 10000 ); // after 10 seconds
}
});
$.xhrPool = {};
$.xhrPool['hash'] = []
$.ajaxSetup({
beforeSend: function(jqXHR,settings) {
var hash = settings.url+settings.data
if ( $.xhrPool['hash'].indexOf(hash) === -1 ){
jqXHR.url = settings.url;
jqXHR.data = settings.data;
$.xhrPool['hash'].push(hash);
}else{
console.log('Duplicate request cancelled!');
jqXHR.abort();
}
},
complete: function(jqXHR,settings) {
var hash = jqXHR.url+jqXHR.data
if (index > -1) {
$.xhrPool['hash'].splice(index, 1);
}
}
});