Without Response.End() code does't works fine - c#

i am using jquery ajax function ,i recieve the data in success function if place Response.End() at server side i didnot understand what is the reason behind this????
<script type="text/javascript">
$(document).ready(function() {
$.ajax({
url: "WebForm1.aspx",
type: "POST",
datatype: "json",
success: function(data) {
alert(reuslt.CustomerID);
}
});
});
In WebForm1.aspx
protected void Page_Load(object sender, EventArgs e)
{
Customer c = new Customer();
c.CustomerID = "1";
c.ContactName = "Jhon";
c.CompanyName = "Dell";
JavaScriptSerializer serializer = new JavaScriptSerializer();
String response = serializer.Serialize(c);
Response.Write(response);
Response.End();
}
Customer Class
public class Customer
{
public string CustomerID { get; set; }
public string CompanyName { get; set; }
public string ContactName { get; set; }
}

You are not using a Webmethod, which means de .aspx file still gives response of the HTML. The Response.end() ends the response, which means no further code is executed.
What you need to do is:
In the VB file:
[System.Web.Services.WebMethod(BufferResponse=false)]
public Customer getCustomer()
{
//implementation code
return new Customer(); // The code you need
}
jQuery:
$.ajax({
type: "POST",
url: "WebForm1.aspx/getCustomer", // Webmethod function here
data: {},
contentType: "application/json;charset=utf-8",
dataType: "json",
async:false,
success: function (json) {
var msg = JSON.parse(json.d);
alert(msg.customerID);
},
failure: function () {
alert("Sorry,there is a error!");
}
});
Information:
Webmethod
jQuery ICM webmethod call (stackoverflow answer)
More info can be found by search jQuery c# Webmethod on Google.
UDPATE
Because Ali want's to specific know why with response.end and without that it fails. Because with response.end will end the request. So no furter code is executed. Which means the HTML is not rendered. Without this code the HTML is rendered and also reponded as the response. Which means the JSON + HTML are the output of the request.
Sends all currently buffered output to the client, stops execution of
the page, and raises the EndRequest event.
Since Response.end throws an exception as quoted from the documentation (above). It is better to use HttpContext.Current.ApplicationInstance.CompleteRequest

I don't know the exact output off hand, but the idea is that you web forms (.aspx) use a page lifecycle. If you don't end the lifecycle by calling Response.End(), the page will continue processing and emitting to the output stream.
Thus, it will eventually reach its render stage and write out the contents of the .asxp file if you don't tell ASP.NET to stop outputting to the response stream.
Try using Fiddler to view the resulting response/html if you don't call Response.End() to see what is returned.
(And also what #Niels said-- my answer is more for a non-ajax implementation)

Related

jQuery POST passing null string on server (ASP.NET)

I have an ASP.NET application sending data through AJAX to a handler withing my application. This works as it should when debugging locally, but as soon as I deploy the solution to the server, the handler only receives an empty string. I tried fiddling around with contentType and dataType, but without luck.
Here is my code so far.
aspx of the sending page, while "myData" is a simple string:
$.ajax({
type: "POST",
url: "handlers/changeRiskGroup.ashx",
data: myData,
// tried all those content/dataTypes without any luck
//contentType: "text/plain",
//dataType: "text",
//contentType: "application/json; charset=utf-8",
//dataType: "json",
error: function (xhr, status, error) {
console.log(xhr.responseText);
},
success: function (msg) {
console.log(msg);
}
});
.ashx.cs of the receiving handler:
public void ProcessRequest(HttpContext context) {
//string data = new StreamReader(context.Request.InputStream).ReadToEnd();
var data = String.Empty;
context.Request.InputStream.Position = 0;
using(var inputStream = new StreamReader(context.Request.InputStream)) {
data = inputStream.ReadToEnd();
}
if (data != "") {
// doing something with my data here.
// this is never reached while on the server, but works fine locally!
} else {
context.Response.Write("Please supply data to the risk group service!");
}
}
public bool IsReusable {
get {
return false;
}
}
}
The data variable in the .ashx.cs file is filled when debugging locally, but always "" on the server. I have no clue why.
var para={};
para.myData="abcd"
$.ajax({
type: "POST",
url: "handlers/changeRiskGroup.ashx",
data: para,
error: function (xhr, status, error) {
console.log(xhr.responseText);
},
success: function (msg) {
console.log(msg);
}
});
from server side
string myData=contect.Request.Form["myData"].toString();
Easy, just took me ~20 hours to figure out. Found the answer here: Web service returns "301 error moved permanently" in production environment
In short, I created a blank page within my project to ensure no plugins etc were interfering with the jQuery execution. Further, I created a very simple mask to submit certain data to the handler URL. Within this mask I varied different ways to POST data, when I tried implementing the POST as a [WebMethod] I finally got a clue, as the response was "301 moved permanently" from the WebMethod. Therefore I could start investigating and found out that my server was lowercasing the urls, obviously jQuery/HTTP does not like that.
I hope this post helps others struggling with similar problems.

Push Table to screen

I have an AJAX request when a branch of my JSSTree is clicked
$("#jstree").bind("select_node.jstree", function(evt, data)
{
var idArgument = data.node.text;
$.ajax(
{
type: "POST",
url: "WebForm1.aspx/brancheSelectionnee",
data: JSON.stringify({ id: idArgument }),
contentType: "application/json; charset=utf-8",
success: function(msg)
{
;
}
});
});
So, I call this function, which make a new "page" (because it's static) and call a function that return a System.Web.UI.WebControls.Table.
public static string brancheSelectionnee(string id)
{
var page = (WebForm1)HttpContext.Current.CurrentHandler;
System.Web.UI.WebControls.Table tableau = page.brancheSelectionneeNonStatique(id);
var stringWriter = new StringWriter();
using (var htmlWriter = new HtmlTextWriter(stringWriter))
{
tableau.RenderControl(htmlWriter);
}
string tableauString=stringWriter.ToString();
return "randomstring";
}
Big problem here: My "tableau" is updated, with what I want (I see this with the htmlWriter) but.. I don't know how put it in my screen!
I have it in my C# code, but I want it in the screen, and not just here.
I have "tableauArticle" which is a real System.Web.UI.WebControls.Table, in my ASP.net code.
I tried some things, like putting "tableauArticle" as Static, then
tableauArticles = tableau;
But I didn't see any changement. I think that I updated a table in the page that I don't display
I think that the main problem is that my pagee isn't refresh or I do my tables wrong.
You do an AJAX request, so there is no page refresh. You just get a string (with HTML) back from your server method. You then have to manually put that string on your page. This happens in the success callback function which in your code is empty. As first step try something like this:
success: function(msg)
{
$('<div class="newtable">').html(msg).appendTo('body');
}
On the server-side your method brancheSelectionnee needs the AjaxMethod attribute so that it can be called with AJAX:
[Ajax.AjaxMethod()]
public static string brancheSelectionnee(string id)
(It also should return tableauString; not "randomstring", right?. And I am not sure if you can use the HttpContext.Current.CurrentHandler there, but that is for a second step if the basic AJAX stuff works.)
Here is one tutorial for all this which gives you an overview.
For the answer, it is 100% Raidri solution :
$('#tableauArticles').empty();
$('<div class="newtable">').html(msg.d).appendTo('#tableauArticles');

Server result to webpage

I am trying to simply write out some data to my webpage as a result of a callback. Everything works up until the point where I need to output the result of the callback.
Client-side:
function toServer(data) {
var dataPackage = data + "~";
jQuery('form').each(function () {
document.getElementById('payload').value = JSON.stringify({ sendData: dataPackage });
$.ajax({
type: "POST",
async: true,
url: window.location.href.toString(),
data: jQuery(this).serialize(),
success: function (result) {
//this does not work because it just puts an entire source code copy of my site in there instead...
//document.getElementById('searchResults').value = result
console.log("callback compelete");
},
error: function(error) {
console.log("callback Error");
}
});
});
}
Server-Side: (on page load)
//holds actions from page
string payload = HttpContext.Current.Request.Form["payload"] ?? String.Empty;
// See if there were hidden requests (callbacks)
if (!String.IsNullOrEmpty(payload))
{
string temp_AggregationId = CurrentMode.Aggregation;
string[] temp_AggregationList = temp_AggregationId.Split(' ');
Perform_Aggregation_Search(temp_AggregationList, true, Tracer);
}
else
{
HttpContext.Current.Session["SearchResultsJSON"] = "";
}
The rest of the server-side code works properly and just handles the parsing of the incoming and performs a search of the db and then parses the search results into a JSON obj.
Currently, the only way the json obj gets written to the page is if I call it without the callback (just call it on page load). Also, in firebug, it looks like the entire page source is posting back as the 'result' of the callback. I do see my json result within the posted back 'result' but it also contains the entire page HTML.
Moreover, I can't seem to get the result to post to the page which is the whole point. Actually, I could get the result to post to the page by simply uncommenting that bit in the client side code but it posts a copy of my site and not the actual result I thought I created...
What am I missing? How do you explicitly state in the C# code what is returned to the JS callback as 'result'?
You get the entire page because you're making a request to an ASP.NET page. In fact, you're requesting the vary same page you're viewing. The server is returning what it would return if you were submitting a form.
To get JSON data, you need to create a web method to handle your request. Read this article, it will help you. It shows you how to return simple text, but you can return JSON too. Information on this MSDN article.
Finally, to make sure jQuery is parsing the server response as JSON, change your request and indicate it explicitly:
function toServer(data) {
var dataPackage = data + "~";
jQuery('form').each(function () {
document.getElementById('payload').value = JSON.stringify({ sendData: dataPackage });
$.ajax({
type: "POST",
async: true,
url: window.location.href.toString(),
data: jQuery(this).serialize(),
dataType: 'json',
success: function (result) {
//this does not work because it just puts an entire source code copy of my site in there instead...
//document.getElementById('searchResults').value = result
console.log("callback compelete");
},
error: function(error) {
console.log("callback Error");
}
});
});
}

Passing an array from javascript to code behind - C#

In my website, i'm declaring an array in javascript and insert them elements dynamically. So now, I want use that array from my C# code. I don't want use ajax to send that element to an web service... I just want use an C# event, like OnClick and access the array that was build in javascript.
I searched for an answer but I just found the oposite.
Thanks
The easiest way is AJAX call and i don't understand why you are avoiding that ?
Make an AJAX call from your button click.
look here a demo :
Ajax call is not calling to the server side and in httpfox shows error as "Error loading content (NS_ERROR_DOCUMENT_NOT_CACHED)" in ajax post call
for example : covert your array to a json string and call a web client in your c# code. Here i have a button . on button click i want to send my GRIDVIEW data to c# method(web method).
you need to remember that while sending json data using stringfy() method,
in server side we need to define the parameter as object.
not any other format like string/int/bla bla.....
use Scripts/jquery-1.8.3.min.js
http://code.jquery.com/ui/1.10.3/jquery-ui.js
$('#btnResult').on('click', function () {
var mydata = [];
$("#<%=GridProjectDetails.ClientID %> tr").each(function () {
var myObject = new Object();
var id = $(this).find("input[name*='ID']").val();
var locationcode = $(this).find("input[name*='TextLocationCode']").val();
var Location = $(this).find("input[name*='TextLocation']").val();
myObject.id = id;
myObject.locationcode = locationcode;
myObject.Location = Location;
mydata.push(myObject);
});
var myString = JSON.stringify({ details: JSON.stringify(mydata) });
alert(myString);
var exportdata = myString;
$.ajax({
type: "POST",
url: "Default.aspx/ExportToExcel",
data: exportdata,
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (data) {
$("#Result").text(data.d);
},
error: function () { alert(arguments[2]); }
});
});
});
and server side method should be
[WebMethod]
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public static string ExportToExcel(object details)
{
return "Message : Success";
}
It's a kinda weird thing to do, but if you have to do it, you can do it by creating a form, inside the form have a hidden text field and call a function when submitting to update the value of this field.
The markup:
<form id="yourForm" method="post" >
<input type="text" name="hiddenFieldName" id="hiddenFieldName" hidden="hidden" />
</form>
The javascript:
void yourProcedure() {
var yourArray = ["Value1", "Value2", "Value3", "Value4"];
document.getElementById('hiddenFieldName').value = yourArray.join();
document.getElementById("yourForm").submit();
}
Then in the server, the form variable will contain "Value1,Value2,Value3,Value4".

Pass a parameter to server method using JavaScript

I have a public in my code behind page that takes a string.
I would like to call this method from javascript.
The parameter that I want to pass down is variable that changes from a ddl.
So I have something like this:
var value = document.getElementById('ddlContact').value;
<%=PopulateContactFields("value") %>
This passes down the word 'value' and not the data in value.
I can't figure out the proper syntax to pass down the data in value.
Thanks
As mentioned by others, trying to access C# code behind directly from javascript is impossible.
However, you can communicate with it indirectly.
I think your best shot is to use a combination of jQuery and the [WebMethod] attribute.
javascript function using jQuery to do an AJAX call:
function Search() {
var search = $('#<%= ddlContact.ClientId %>').val();
var options = {
type: "POST",
url: "Default.aspx/Hello",
data: "{'name' :'" + search + "'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function(msg) {
alert(msg);
}
};
$.ajax(options);
}
Code behind:
public partial class _Default : System.Web.UI.Page
{
[WebMethod]
public void Hello(string name)
{
return "Hi " + name;
}
}
The code you are showing is executed server side when the HTML is generated. In other words it is executed BEFORE it hits the browser and your user had a chance to do anything with the page.
No matter what syntax you would use here the information you want cannot be accessed at this time - it does not exist yet.
The right approach here is to sent this information to the server either by posting the page or using AJAX and then, on the tail end of request/response cycle do your processing
Another option would be to do the processing client side using Javascript

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