access/iterate over a C# list in jQuery - c#

i am trying to make an image gallery with pictures fading in and out. I already have that part covered, but so far im hard coding the image url's in my .aspx page. I don't want this, i need it to be dynamic.
<script type="text/javascript">
$(function()
{ var img = $("img.x");
$(img).hide().eq(0).show();
var cnt = img.length
setInterval(imgRotate, 5000);
function imgRotate() {
$(img).eq((img.length++) % cnt).fadeOut("slow",
function() {
$(img).eq((img.length) % cnt).fadeIn("slow");
});
}
});
</script>
<body>
<form id="form1" runat="server">
<div>
<img class="x" alt="Image1" src="Desert.jpg"/>
<img class="x" alt="Image1" src="Lighthouse.jpg"/>
</div>
</form>
this makes the images fade in and out, which is good, but as you can see, i've hardcoded the images in this example. I can't use this for my application.
What i want to do is the following:
i want to pass a List<string> (codebehind) to the jQuery script that will just iterate over the list and replace the source url of the image.
i just want to do something like this in the jQuery script (pseudo-code):
int counter = 0;
var img = ListFromCodeBehind[counter];
//do some fading stuff
count++;
i've tried using <%=%> server tags, and so forth but to no avail. I've read lots of things but they all seem overly complicated for what i'm trying to achieve..

Why is everybody forcing you to use AJAX? There is no need to load image list in separate HTTP request. I assume your code comes from some aspx page. Therefore you can provide a public method in this Pages's class (lets call it GetImages()) that returns a string that looks like JavaScript array. I.e.
public string GetImages()
{
return "['Desert.jpg', 'Lighthouse.jpg']";
}
Then in you JavaScript code (that is placed in this Page's aspx file as well) you can call public method of Page's class with classic ASP syntax:
int counter = 0;
var ListFromCodeBehind = <%= this.GetImages() %>;
var img = ListFromCodeBehind[counter];
//do some fading stuff
count++;
which will finally print:
var ListFromCodeBehind = ['Desert.jpg', 'Lighthouse.jpg'];
and this is the result I believe you expect.

You can add a Web Method into your aspx page (code behind) that can be called by AJAX.
Your code behind method will return a string that contains the URL to the images, in a JSON format (so that JQuery knows how to iterate though it out of the box).
Have a look at this thread to have an idea of how to create a web method in an aspx code behind file. I'd do it via asp.net MVC though...much more straightforward
Calling an ASP.NET server side method via jQuery

//Controller
[HttpGet]
public JsonResult GetImageURLS()
{
var urls = GetUrls();
return Json(new { urls = urls }, JsonRequest.AllowGet);
}
//js file
$.ajax({ url : '/GetImageURLS/', success : function(e) { if (e && e.urls) {
var $images = $(".images");
for (var i in e.urls) {
$images.append('<img src="' + i.url + '" class="x" ' + ' alt="' + i.alt + '" /> ';
}
});
//html
<div class="images">
</div>
Try this for initial load of the images. Then call your function on them after the images are populated.

You can use AJAX and call a webservice in your Javascript to return your image list as follows:
function LoadImages() {
var url;
url = "WebServices/wsImages.asmx/GetImageList"
$.ajax({
type: "POST",
url: url,
contentType: "application/json; charset=utf-8",
error: function (XMLHttpRequest, textStatus, errorThrown) {
alert(textStatus);
},
success: function (response) {
var imgList = response.d;
//Loop through image list etc.
}
});
}

Related

Using Action in Controller every 10min [duplicate]

I have sample code like this:
<div class="cart">
<a onclick="addToCart('#Model.productId');" class="button"><span>Add to Cart</span></a>
</div>
<div class="wishlist">
<a onclick="addToWishList('#Model.productId');">Add to Wish List</a>
</div>
<div class="compare">
<a onclick="addToCompare('#Model.productId');">Add to Compare</a>
</div>
How can I write JavaScript code to call the controller action method?
Use jQuery ajax:
function AddToCart(id)
{
$.ajax({
url: 'urlToController',
data: { id: id }
}).done(function() {
alert('Added');
});
}
http://api.jquery.com/jQuery.ajax/
Simply call your Action Method by using Javascript as shown below:
var id = model.Id; //if you want to pass an Id parameter
window.location.href = '#Url.Action("Action", "Controller")/' + id;
You are calling the addToCart method and passing the product id. Now you may use jQuery ajax to pass that data to your server side action method.d
jQuery post is the short version of jQuery ajax.
function addToCart(id)
{
$.post('#Url.Action("Add","Cart")',{id:id } function(data) {
//do whatever with the result.
});
}
If you want more options like success callbacks and error handling, use jQuery ajax,
function addToCart(id)
{
$.ajax({
url: '#Url.Action("Add","Cart")',
data: { id: id },
success: function(data){
//call is successfully completed and we got result in data
},
error:function (xhr, ajaxOptions, thrownError){
//some errror, some show err msg to user and log the error
alert(xhr.responseText);
}
});
}
When making ajax calls, I strongly recommend using the Html helper method such as Url.Action to generate the path to your action methods.
This will work if your code is in a razor view because Url.Action will be executed by razor at server side and that c# expression will be replaced with the correct relative path. But if you are using your jQuery code in your external js file, You may consider the approach mentioned in this answer.
If you do not need much customization and seek for simpleness, you can do it with built-in way - AjaxExtensions.ActionLink method.
<div class="cart">
#Ajax.ActionLink("Add To Cart", "AddToCart", new { productId = Model.productId }, new AjaxOptions() { HttpMethod = "Post" });
</div>
That MSDN link is must-read for all the possible overloads of this method and parameters of AjaxOptions class. Actually, you can use confirmation, change http method, set OnSuccess and OnFailure clients scripts and so on
If you want to call an action from your JavaScript, one way is to embed your JavaScript code, inside your view (.cshtml file for example), and then, use Razor, to create a URL of that action:
$(function(){
$('#sampleDiv').click(function(){
/*
While this code is JavaScript, but because it's embedded inside
a cshtml file, we can use Razor, and create the URL of the action
Don't forget to add '' around the url because it has to become a
valid string in the final webpage
*/
var url = '#Url.Action("ActionName", "Controller")';
});
});
Javascript Function
function AddToCart(id) {
$.ajax({
url: '#Url.Action("AddToCart", "ControllerName")',
type: 'GET',
dataType: 'json',
cache: false,
data: { 'id': id },
success: function (results) {
alert(results)
},
error: function () {
alert('Error occured');
}
});
}
Controller Method to call
[HttpGet]
public JsonResult AddToCart(string id)
{
string newId = id;
return Json(newId, JsonRequestBehavior.AllowGet);
}
You can simply add this when you are using same controller to redirect
var url = "YourActionName?parameterName=" + parameterValue;
window.location.href = url;
You can set up your element with
value="#model.productId"
and
onclick= addToWishList(this.value);
I am using this way, and worked perfectly:
//call controller funcntion from js
function insertDB(username,phone,email,code,filename) {
var formdata = new FormData(); //FormData object
//Iterating through each files selected in fileInput
formdata.append("username", username);
formdata.append("phone", phone);
formdata.append("email", email);
formdata.append("code", code);
formdata.append("filename", filename);
//Creating an XMLHttpRequest and sending
var xhr = new XMLHttpRequest();
xhr.open('POST', '/Home/InsertToDB');//controller/action
xhr.send(formdata);
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
//if success
}
}
}
in Controller:
public void InsertToDB(string username, string phone, string email, string code, string filename)
{
//this.resumeRepository.Entity.Create(
// new Resume
// {
// }
// );
var resume_results = Request.Form.Keys;
resume_results.Add("");
}
you can find the keys (Request.Form.Keys), or use it directly from parameters.
You can easily make a <a> link in your view.
<a hidden asp-controller="Home" asp-action="Privacy" id="link"></a>
then in you javascript code use this:
location.href = document.getElementById('link').href;

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".

How can I make a continually updating query in MVC 3?

I am looking for a simple way to make a piece of text, which happens to be a number, on my view update in near-real-time.
I have a piece of text in my view that looks like this:
<% if (ViewData["TotalRecords"] != null)
{ %>
<%= ViewData["TotalRecords"].ToString() +
" records available to search."%>
<% } %><br />
I want ViewData["TotalRecords"] to be a constantly updating value, every 60 seconds or so.
The query underneath is:
public static string GetTotalRecords()
{
DataContext dc = new DataContext();
return dc.Records.Count().ToString("#,##0");
}
How can I make this into some kind of Ajax-enabled dynamic piece of text?
Move that part to separate action
public ActionResult TotalRecords()
{
var totalRecords = GetTotalRecords();
return PartialView(totalRecords);
}
In parent view, initially render that action with
<div id="totalRecords">
#Html.RenderAction("TotalRecords")`
</div>
And script with setInterval to reload TotalRecords action every 60 seconds
<script>
$(function(){
setInterval("reloadTotalRecords", 60 * 1000);
});
function reloadTotalRecords()
{
$('#totalRecords').load('#Url.Action("TotalRecords")');
}
</script>
There's going to have to be some JavaScript in there somewhere. A setTimeout could be used to call an ajax method that returns the number, which then is used to update the content in the browser.
You could use jQuery to target the specific element. There are some examples on this question.
I believe this should solve your question:
jQuery Ajax setTimeout JSON
Use the JavaScript setTimeout function to call an Ajax function every 60 seconds.
Something like:
function updateContent() {
$.ajax({
url: 'url',
cache:false,
success: function(data) {
$('#item-id').html(data.NewValue);
},
dataType: 'json'
});
}
$(function () {
setTimeout(updateContent, 60000);
}
I would jump into SignalR. Sounds interesting.

How to get label value which loads with javascript

I have a link like that. It's getting from instagram api.
http://localhost:60785/access_token.aspx/#access_token=43667613.4a1ee8c.791949d8f78b472d8136fcdaa706875b
How can I get this link from codebehind?
I can take it with js but i can't get it after assign to label. I mean:
<script>
function getURL(){
document.getElementById('lblAccessToken').innerText = location.href;
}
</script>
This js function is in body onload event. How can I reach this innerText value from codebehind?
If you are using ASP.NET 4.0 and jQuery, its fairly easy. Otherwise you may have to deal with mangled id and have to deal with DOMReady on your own. Try this
Markup
<asp:Label ID="lblAccessToken" runat="server" ClientIDMode="Static"></asp:Label>
JavaScript
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script>
$(document).ready(function(){
var myToken = GetHashParameterByName("access_token");
$("#lblAccessToken").html( myToken );
});
function GetHashParameterByName(name) {
var match = RegExp('[#&]' + name + '=([^&]*)')
.exec(window.location.hash);
return match && decodeURIComponent(match[1].replace(/\+/g, ' '));
}
</script>
You want the value on Page_Load right? I haven't figured out a way myself to fetch the hash value on Page_Load.I usually do one of these things
Pass the hash value to a jQuery ajax method and store it there.
Grab the hash value and redirect to the same page after converting it to a querystring
JavaScript
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script>
$(document).ready(function(){
var myToken = GetHashParameterByName("access_token") || "";
if(my_token !=== ""){
window.location = window.location.split("/#")[0] + "?access_token=" + myToken;
}
});
function GetHashParameterByName(name) {
var match = RegExp('[#&]' + name + '=([^&]*)')
.exec(window.location.hash);
return match && decodeURIComponent(match[1].replace(/\+/g, ' '));
}
</script>
Now at Page_Load, grab it like
string token = Request.QueryString["access_token"];
Please note that it takes one more round trip to the server and so not very efficient. But this is what I do.

Redirecting to another page in ASP.NET MVC using JavaScript/jQuery

I want to redirect from one page to another page in ASP.NET MVC 3.0 using JavaScript/jQuery/Ajax. On button click event I have written JavaScript code like below.
function foo(id)
{
$.post('/Branch/Details/' + id);
}
My controller code is like this:
public ViewResult Details(Guid id)
{
Branch branch = db.Branches.Single(b => b.Id == id);
return View(branch);
}
When I click on a button it is calling the Details action inside BranchController, but it doesn't return to the Details view.
I didn't get any error or exception. It's showing status 200 OK in Firebug. What is wrong in my code and how can I redirect to the Details view page?
You are not subscribing to any success callback in your $.post AJAX call. Meaning that the request is executed, but you do nothing with the results. If you want to do something useful with the results, try:
$.post('/Branch/Details/' + id, function(result) {
// Do something with the result like for example inject it into
// some placeholder and update the DOM.
// This obviously assumes that your controller action returns
// a partial view otherwise you will break your markup
});
On the other hand if you want to redirect, you absolutely do not need AJAX. You use AJAX only when you want to stay on the same page and update only a portion of it.
So if you only wanted to redirect the browser:
function foo(id) {
window.location.href = '/Branch/Details/' + id;
}
As a side note:
You should never be hardcoding urls like this. You should always be using url helpers when dealing with urls in an ASP.NET MVC application. So:
function foo(id) {
var url = '#Url.Action("Details", "Branch", new { id = "__id__" })';
window.location.href = url.replace('__id__', id);
}
This could be done by using a hidden variable in the view and then using that variable to post from the JavaScript code.
Here is my code in the view
#Html.Hidden("RedirectTo", Url.Action("ActionName", "ControllerName"));
Now you can use this in the JavaScript file as:
var url = $("#RedirectTo").val();
location.href = url;
It worked like a charm fro me. I hope it helps you too.
You can use:
window.location.href = '/Branch/Details/' + id;
But your Ajax code is incomplete without success or error functions.
// in the HTML code I used some razor
#Html.Hidden("RedirectTo", Url.Action("Action", "Controller"));
// now down in the script I do this
<script type="text/javascript">
var url = $("#RedirectTo").val();
$(document).ready(function () {
$.ajax({
dataType: 'json',
type: 'POST',
url: '/Controller/Action',
success: function (result) {
if (result.UserFriendlyErrMsg === 'Some Message') {
// display a prompt
alert("Message: " + result.UserFriendlyErrMsg);
// redirect us to the new page
location.href = url;
}
$('#friendlyMsg').html(result.UserFriendlyErrMsg);
}
});
</script>
<script type="text/javascript">
function lnkLogout_Confirm()
{
var bResponse = confirm('Are you sure you want to exit?');
if (bResponse === true) {
////console.log("lnkLogout_Confirm clciked.");
var url = '#Url.Action("Login", "Login")';
window.location.href = url;
}
return bResponse;
}
</script>
check the code below this will be helpful for you:
<script type="text/javascript">
window.opener.location.href = '#Url.Action("Action", "EventstController")', window.close();
</script>

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