How To Execute Serverside Code In Parallel With Client Side Code
Aug 2, 2010
I have a web app that needs to do two things at the same time. After a user clicks a button on the site, a javascript function needs to execute and while thats working I need the server side code for the button click to execute without waiting on the client side to finish.
To be more specific, the client side function takes about 23 seconds to complete, and while that is running the server side code promts the user for printing a document. So I need the javascript to run "in the background".
i am not sure if my design have flaw but would like to know what others have to say, i am in a situation where i am trying to acheive two things in one click.
using : asp.net web form
i have a web form with few textbox and a gridview control and a button.
if i click on the button i am executing two things
1) asynchronously get data from server to client (working great) and able to display the data in the textboxes.
2) same click i want to bind the gridview.
[Code]....
recap:
1) jquery script execute asynchronously to get data from server to client and display in the textboxes 2) server side code to bind the gridview.
PROBLEM:
if i have onClientClick="return LoadDataById(); then it executes ONLY ajax code and does not execute server side but if have onClientClick="LoadDataById(); then it executes client and server but textbox value wipeout. (the textbox value popuplate through ajax)
I have a button where I use an Animation Extender. When I click the button I have to set OnClientClick="return false;" otherwise the Animation Extender closes. So that causes my problem. How do I execute server side code from this button? I have tried this code in my code behind, but there is an error:
Code: Dim strScript As String strScript = "<script>" strScript = strScript & "return false;" strScript = strScript & "</script>" ScriptManager.RegisterStartupScript(Me, GetType(Page), "MyScript", strScript, False) This is my code for the Animation Extender: Open data"></asp:Button>
When a user clicks a button I need to create a .bmp file on the server. After the .bmp file is created I will load it into the html page. Would Ajax be the best way to accomplish this?
Executing Server side code using Javascript. Here is the solution.In the Asp.net forums, I often see the question asked, "Can I call server-side code from the client/JavaScript?" Almost invariably, the responses given are "No, the client cannot access the server," or "You can only use WebMethods or PageMethods." The first response is not entirely correct, and unfortunately, WebMethods and PageMethods are static methods and therefore have no way to directly access the page.This is why I present to you the following "hack". I call it a hack because there really should be some way built into the ASP.NET AJAX Extensions that allow this approach directly. Instead, it relies on using controls in a manner that they aren't necessarily intended in order to obtain the desired result. But this "hack" does have a redeeming quality—it's incredibly easy.The Code:
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default2.aspx.vb" Inherits="Default2" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
in a form i have a buttoin, when click both OnclientClick and postback should happen. on clicking the "Email" button a client side "mailto" tag should do the work and pull a new message window on the client's machine.
whereas, the email addresses should be invoked by the post back. so , when clicking the button the server side post should happen and on return the client side script should be invokded with the values read during post back, and populate all the email addresses.
i need know how to first do a server hit take the values and then execute the client script with those values without using AJAX
If I have a standard HTML textbox: I can retrieve the value using Request.Form. But how do I go about populating this textbox from the server-side? I tried Request.Form["txtTest"] = "blah"; but got a readonly error.
In my asp.net website I am creating a session upon user login and I would like to perform some operations in the database just before this session will expire.I am having problem in determining where should I write code and how will I know the session is going to expire.
I am not sure if 'session_end' event of 'Global.asax' suits my requirements as the session I want to check is created manually(not a browser instance).
I have code on my server which works very well. It must crawl a few pages on remote sites to work properly. I know some users may want to abuse my site so instead of running the code which uses webclient and HttpRequest i would like it to run on client side so if it is abused the user may have his IP blacklisted instead of my server. How might i run this code client side? I am thinking silverlight may be a solution but i know nothing about it.
I am a quite new to web development and I am trying to do some small form updates without causing a postback. For example making a control visible when a drop down list is changed.
I have so far come across some features that achieve this like the RequiredFieldValidator inside an update panels. However, these are specific to a single task.
What are my options to achieve these client side updates in Visual Studio? At the moment I don't know any JavaScript, so I would prefer another solution if it exists.
I have a question, I am writing a user tracking class that needs to obtain the screen resolution of the user. I have the javascript all written and it is working along with a hidden variable ( used to set the javascript vars so I can access them server side ). What I am running into is when I try to access the value of the hidden variable on Page load it's not there, but If I cause a post back I can get it. How can I access this data on page load? There is no guarantee that the user will ever cause a postback, some users just look at the home page and leave.
I am having issues correctly setting up reference to javascript code to a custom validator.This is my javascript code in the .aspx page.
[Code]....
And here is where I add the Client Validation to the customer validator in the code behind. [Code]....
The validation is if there is a value present in the first text box then the second text box is required.The page throws an error when the validation should fail, but if I ignore the error the validation works correctly.Do I need to move my javascript to the code behind as well?
i appologise if thisis a silly question but i just want to be completely sure something is not possile before i tell this to my manager.
i am a WinForms programmer by trade, but i have put in charge of making a web site for our sales team, and web development is a new area for me. the web site is written in ASP.NET, C# code. it is finished, however they are complaining that there are too many page refreshes.
first of all, we have an SQL server with all our data in it. on the main web page, the user must select their country of interest from a DropDownList. when they do this, all our customers from that country are displayed in an html table, generated by a Repeater. i have set AutoPostBack on the country DropDownList to true, so each time the user selects a different country, the SelectedIndexChanged event handler is called, and in here i generate a new sql statement with the selected country, and re-bind the Repeater.
There are also a few other DropDownLists that do other 'filtering' stuff. for example, one DropDownList selects whether to display customers whose license expires soon (within a week), and another DropDownList filters the customers who currently have an open support case. All the DropDownLists have their AutoPostBack set to true, and in their SelectedIndexChanged event handler, i work out the sql based on the values of the DropDownLists, and re-bind the Repeater.
the problem with the above is that each time the user selects a different value from the DropDownList, the page refreshes, clearly because the AutoPostBack is set to true for them all. so to stop this i need to set AutoPostBack to false - but then of course the SelectedIndexChanged event handlers are not called, and so i have no place to rebind the repeater with my new sql statement.
so what i really need, is to be able to set a DropDownList's AutoPostBack to false, and handle the rebinding of the Repeater in some client-side event, which does NOT result in a postback. the Repeater will be bound by some sql, which is generated by the values in the DropDownLists (eg "SELECT * FROM custTable WHERE [Country]='" + CountryDropDownList.Text + "'"), so in this client-side event i need to be able to reference the asp.net controls.
I know that I can receive an javascript object from the server via ASP.NET AJAX using Json. But I am not sure how can I send an javascript object from my client-side javascript to my server-side code. And if I can, how can I extract this object in my server-side code and access its members?
im tryin to upload files to the database using the FileUpload. the upload take place. when i download the file again ( word document, excel document.. a text document (.txt), a winzip file) , it turns that the file is corrupted and cannot be opened.. an image file or an mp3 file doesnt present this problem. my application is developped usin vb.net 2010 and sql server 2005 as the database..
I have a multiline textbox that by default, is set to ReadOnly. I would like a button on the page to change the control to allow it to be edited. I would like this code to run on the client side because the page renders slowly and I'd like to avoid the post back.
The problem I'm having is the javascript code that I wrote to remove the readonly attribute appears to have no effect. I posted a stripped down example that illustrates the problem for your review.
