XMLHttpRequest to the MongoDB simple rest interface - javascript

I am a beginner in both Ajax and MongoDB. I was hoping to visualize some of the data in my MongoDB using a web browser (which, for the moment, is running on the same host). For this, I thought it might be possible to get the data using XMLHttpRequests. I am running MongoDB with the --rest option and I checked that when I load hxxp://localhost:28017/test_db/ss_test/
on Firefox, I get the proper reply (a JSON document with the data in the ss_test collection of the test_db database). So far, so good.
I then wrote the following JavaScript function which I connected to the "onclick" of a button:
function makeRequest()
{
var myrequest = new XMLHttpRequest();
myrequest.onreadystatechange = function()
{
alert("status=" + myrequest.status + " readyState=" + myrequest.readyState)
if (myrequest.status == 200 && myrequest.readyState == 4)
{
// ...do something with the response
}
}
myrequest.open("GET", "http://localhost:28017/test_db/ss_test/", true);
myrequest.send();
}
So, when I load the html file on Firefox, open the console and click on my button, I see that the http request is indeed made, the status code is "HTTP/1.0 200 OK" and a response with Content-Length: 219257 is delivered, which looks great. However, the XMLHttpRequest object does not report the status=200. The alerts that pop up report a constant status of 0 as the readyState progressively becomes 1, 2 and 4 and my if statement is never true.
Could anyone please tell me what I am doing wrong? In the beginning I thought it was because my html was loaded on the browser by the file protocol or that I was seeing some same-origin policy related issue, but then I put the html file on a web server on localhost and loaded it from there and nothing changed. Thank you very much for any replies!

you need to create a function to handle the request.
http://www.ibm.com/developerworks/web/library/wa-ajaxintro2/
http://www.ibm.com/developerworks/library/wa-ajaxintro3/
function makeRequest()
{
var myrequest = new XMLHttpRequest();
myrequest.onreadystatechange = create_this_function()
{
}
myrequest.open("GET", "http://localhost:28017/test_db/ss_test/", true);
myrequest.send();
}
#
function create_this_function()
{
alert("status=" + myrequest.status + " readyState=" + myrequest.readyState)
if (myrequest.status == 200 && myrequest.readyState == 4)
{
// ...do something with the response
}
}

Related

Difference between Electron-based XMLHttpRequest and browser-based URL with query string?

I'm working on an Electron app and trying to integrate the Easy Digital Downloads Software Licensing WordPress plugin. I haven't done much with HTTP communication in Electron/Javascript so this may be a naive question.
The problem: I am able to get a license activation response from my EDD server and while there is no specific error, for some reason a license is not activated. The odd thing is that if I use a URL and query string in a browser with the same data, the plugin responds as expected: I can activate, deactivate and check the status of a license.
So EDD seems to be working and there are no errors with Electron. But something is missing. Initially I was using the net Electron module but after this issue came up, I switched to using the example script from EDD (below) which uses XMLHttpRequest. With that I get the following response back:
{"success":true,"license":"valid","item_id":539,"item_name":"My
Awesome App","license_limit":1,"site_count":0,"expires":"2020-12-19
23:59:59","activations_left":1,"checksum":"f2d66c6844b37d1fa931b813c408",
"payment_id":248,"customer_name":"Marvin
Gardens","customer_email":"marvin#home.com","price_id":false}
Which is fine except that "activations_left":1 never changes and it should given "license_limit":1. So something is wrong.
On the other hand, if I use a URL with a query string in a browser, the "activations_left" is decremented and license activation only works once (as it should). For example, this works:
http://YOURSITE.com/?edd_action=activate_license&item_id=8&license=cc22c1ec86304b36883440e2e84cddff&url=http://licensedsite.com
My Question: is there some fundamental difference between these two methods? Is there something I need to add to my XMLHttpRequest? I have a support ticket open with EDD but I need to keep moving with this. And sorry to be so long-winded!
UPDATE:
#aw04 suggested I try using GET – just tried that and I "get" the same response as before: no error but also no activation.
Could there be some property which should (or shouldn't) be in the Electron request which is (or isn't) in a browser request by default?
xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function () {
if (this.readyState === XMLHttpRequest.DONE && this.status === 200) {
console.log('xhttp.responseText', xhttp.responseText);
}
}
var url = "http://YOURSITE.com/?edd_action=activate_license&item_id=8&license=cc22c1ec86304b36883440e2e84cddff"
xhttp.open("GET", url);
xhttp.send();
var xhttp = new XMLHttpRequest();
var postUrl = 'http://<domain.com>/edd-sl/';
xhttp.onreadystatechange = function() {
if (xhttp.readyState == 4 && xhttp.status == 200) {
console.log(xhttp.responseText);
}
}
var data = {
edd_action: 'check_license',
license: '<license key>',
item_name: encodeURIComponent('<item name>'),
};
xhttp.open("POST", postUrl, true);
xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhttp.setRequestHeader("Access-Control-Allow-Origin", "http://local.dev");
var values = '';
for (var key in data){
values += key + '=' + data[ key ] + '&';
}
values = values.substring(0, values.length - 1);
xhttp.send(values);
Based on some help from Easy Digital Downloads support folks, this is resolved.
The issue had to do with a property in their Software Licensing plugin setup: "Do not check URL". I hadn't enabled that with the result that my API call from Electron failed and the one using a browser succeeded because the browser was adding headers that Electron was not.
After enabling "Do not check URL", calls from within Electron work. I guess there is also an option to pass in a URL, but since I am using EDD for licensing desktop software, that didn't seem like a needed option.
Anyway, hope this helps someone.

How to get text data from webpage

I am trying to get data form a website about institution using XMLHttpRequest but rather than data I am getting error page please help
My code:-
var url = '[https://tsecet.nic.in/institute_details.aspx?iCode=JNTH][3]';
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
// Typical action to be performed when the document is ready:
document.write( this.responseText);
}
}
xhttp.open("GET", url , true);
xhttp.send();
Target Web Page Address:-
https://tsecet.nic.in/institute_details.aspx?iCode=JNTH
If I try to open
https://tsecet.nic.in/Default.aspx>>then click on >>
institute profile >> then click on>>JNTH
Then I am able to get data in browser Else I am redirected to an error page
Please help me...
Note
I am trying to get this data from a different website and a different
domain This website is scripted in aspx
The AJAX request you're trying to run can't do that, as the pages have the X-XSS-Protection: 1 header, blocking such requests. It looks as if they allow the internals URIs to launch only within a "frame" set by the homepage. Unfortunately, I can't tell for sure. In short, you are going to need another approach.

cannot manipulate response from xmlHttpRequest 2

I'm using XHR 2 to upload/save files.
According to the response of the server I want to perform an action. For example if the responce is "Saved" I want to hide a div or if the response is "Not Saved" I want to show another div etc...
I implemented what appears to be a simple code that should be working , but is not
Here is the snippet of the XHR
//initialize
var xhr = new XMLHttpRequest();
xhr.open('POST', 'upload.php');
xhr.responseType="text";
xhr.onload = function() {
//if all ok....
if (xhr.status === 200)
{
//update html5 progress bar
progress.value = progress.innerHTML = 100;
//get the respnse
var data=xhr.response;
//convert it to sting - kind of overkill, I know, but I'm stack
var data2=data.toString();
//alert it -- works
alert('data2 '+data2);
//now, do something, according to the response -- NOT working, never alert anything
if (data2=="Not Saved"){alert('Ooops, not saved');}
if(data2=="Saved"){alert('It's all good');}
if(data2=="File too big"){alert('hey, you are watching Jake and Amir');}
document.getElementById('imagesaved').innerHTML=data;
}
//refers to if (xhr.status === 200)
else {document.getElementById("imagesaved").innerHTML="Connect to server failed";}
What is wrong here? This should be working right? Any suggestions?
Thanks
EDIT
I put the alerts for testing. What I actually want to do is call some functions.
If I put
if (data2=="Not Saved"){functionOne();}
if(data2=="Saved"){functionTwo();}
if(data2=="File too big"){functionThree();}
the functions never get called
if I put
if (data2!="Not Saved"){functionOne();}
if(data2!="Saved"){functionTwo();}
if(data2!="File too big"){functionThree();}
ALL the functions are called!!!
I still dont get it...Maybe its something with the response? Or the onload function?
Thanks again
What I finally did is make the server response with numbers, not text. So encoding does not matter any more...
This is the code
var xhr = new XMLHttpRequest();
xhr.onload = function() {
if (xhr.status == 200)
{
var data=xhr.response;
if(data==1)
//say to the user is saved
{document.getElementById('imagesaved').innerHTML="Saved";}
//say to the user, there was an error
else{document.getElementById('imagesaved').innerHTML="Error";}
}
//say to the user that connection to the server failed
else {document.getElementById("imagesaved").innerHTML="Cannot connect";}
};
xhr.open('POST', 'upload.php');
xhr.send(formData);
This is a workaround. I dont know if its the right way to solve this problem , technically. I decided to post it anyway, to help others to quickly solve similar problems. If anyboy else has a better way to suggest , please do.
In this line : if(data2=="Saved"){alert('It's all good');}, you have to escape " ' ".
So convert it to : if(data2=="Saved"){alert('It\'s all good');}
Are you sure that the response of your ajax is text/plain ?
Look on the console (ctrl+shift+i on chrome, F12 on firefox), on net or network tab.
Look on console tab if you got some javascript errors too.

Ajax Function Only Working Part of the Time

I am using the following Ajax function format:
var xmlhttp;
function addAddress(str)
{
if (window.XMLHttpRequest)
{
xmlhttp = new XMLHttpRequest();
}
else
{
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange = function()
{
if (xmlhttp.readyState == 4 && xmlhttp.status == 200)
{
//specific selection text
document.getElementById('info').innerHTML = xmlhttp.responseText;
}
}
var addAddress = "add";
xmlhttp.open("POST", "sys.php", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
var queryString = "&addAddress=" + addAddress;
xmlhttp.send(queryString);
}
function GetXmlHttpObject()
{
if (window.XMLHttpRequest)
{
return new XMLHttpRequest();
}
if (windows.ActiveXObject)
{
return new ActiveXObject("Micorsoft.XMLHTTP");
}
return null;
}
Up until now, all of my Ajax functions, like the one above, have been running fine. However, now the function will work only sometimes. Now, sometimes I will have to click the onclick event a couple times to execute the function or the function will just hang, and then after about 4 minutes it will execute.
I tested parts of the function and found that the issue lies some where at the:
if (xmlhttp.readyState == 4 && xmlhttp.status == 200)
{
alert(xmlhttp.status);
//specific selection text
document.getElementById('info').innerHTML = xmlhttp.responseText;
}
When the function works, I can alert(xmlhttp.status) and get 200. However, when it's not working, the alert box doesn't even trigger. In fact, nothing happens, not even an error.
Could this be a server issue? I am kind of thinking my website got hacked, but I cannot find any issues accept that the Ajax functions are not executing properly.
Lastly, I do not get this problem on my localhost, it's only happening on the live website.
Any help will be greatly appreciated.
Thanks
First just confirm that the addAddress function is actually being called when you click the button or control that should trigger it.
Just a simple alert in the first line like this would work:
function addAddress(str)
{
alert('addAddress has been called!')
....
}
If you don't get the alert, make sure there isn't a javascript error on the page that is preventing the function from running. In firefox you press CTRL+SHIFT+J to see the error console for example.
If that part is working, trying putting the URL for the ajax request directly into your browser and diagnose it that way.
Looks like you are requesting this url with ajax:
sys.php&addAddress= (address goes here)
Check that the page will load directly in your browser. If not, the problem is not the ajax request, but something with the sys.php page itself - which you can then drill down on.
Hope that helps!
This wasn't the answer I was expecting, but I ended up having my web host (GoDaddy) change servers, and that resolved the problem. For almost a year, I was running IIS7 with PHP. Since I had never run into any problems, I just continued using that server. After the Ajax latency issue and not being able to figure out a solution, I figured I would just switch over to Apache. After the change, everything started running smoothly again.
I am thinking maybe there was a software update that I was not notified about. Or, maybe my website was getting hit with a DDoS, which was decreasing the performance of my Ajax requests. Lastly, maybe someone got into IIS and changed a setting. I don't know, all I know is that the minute the server was changed over to Apache was when the website started running normally again.
Thanks for everyone's suggestions.

Problem with making a simple JS XmlHttpRequest call

Edit: Maybe I made the question more complex than it should. My questions is this: How do you make API calls to a server from JS.
I have to create a very simple client that makes GET and POST calls to our server and parses the returned XML. I am writing this in JavaScript, problem is I don't know how to program in JS (started to look into this just this morning)!
As n initial test, I am trying to ping to the Twitter API, here's the function that gets called when user enters the URL http://api.twitter.com/1/users/lookup.xml and hits the submit button:
function doRequest() {
var req_url, req_type, body;
req_url = document.getElementById('server_url').value;
req_type = document.getElementById('request_type').value;
alert("Connecting to url: " + req_url + " with HTTP method: " + req_type);
req = new XMLHttpRequest();
req.open(req_type, req_url, false, "username", "passwd");// synchronous conn
req.onreadystatechange=function() {
if (req.readyState == 4) {
alert(req.status);
}
}
req.send(null);
}
When I run this on FF, I get a
Access to restricted URI denied" code: "1012
error on Firebug. Stuff I googled suggested that this was a FF-specific problem so I switched to Chrome. Over there, the second alert comes up, but displays 0 as HTTP status code, which I found weird.
Can anyone spot what the problem is? People say this stuff is easier to use with JQuery but learning that on top of JS syntax is a bit too much now.
For security reasons, you cannot use AJAX to request a file from a different domain.
Since your Javascript isn't running on http://api.twitter.com, it cannot request files from http://api.twitter.com.
Instead, you can write server-side code on your domain to send you the file.

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