AJAX :: Populating A Series Of Cascading Drop Down Lists Through Code?
Aug 20, 2010
I am new to Ajax in general but I have a series of cascading drop down lists that are working fine. I'm using them on a form that I want to be able to either add a new row of data to the database or edit an existing one. I have the insert a new row working but editing an existing one is a bit trickier. The drop down lists are only part of the form but I would like to be able to query for a row id and set their values. Right now I'm querying for a row of data and populating the form with its values on page load and all of the fields work except for the drop down lists. I assume that this is because when the page is loading the web methods haven't run yet to populate the cascading drop downs. Therefore I can't set the selected value because there aren't any values yet. So therefore I'm pretty sure I need to do this from a web method so that it runs after the lists are populated or while the lists are populating but I don't know how.
I am using the AJAX Cascading drop down list but want to add event validation e.g. the compare validators.
As the cascading drop down list requires the page event validation to be disabled what is the best way to do the validation?
Validation Attempt: I have tried to use a custom validator which calls a Javascript function but it doesnt seem to be picking up the control. I get the following error Microsoft JScript runtime error: Object required
function ValidateCostCentCat(source, arguments) { var countryList = document.getElementById("ddlCategory"); if (null != countryList) { var iValue = countryList.options[countryList.selectedIndex].value; if (iValue == "Select Category") { arguments.IsValid = true; } else { arguments.IsValid = false; } } }
The mark-up for the custom validator is
<asp:CustomValidator ID="valcustCategory" runat="server" CssClass="error" Display="Dynamic" ValidationGroup="DirectHire" ClientValidationFunction="ValidateCostCentCat" ErrorMessage="Please select a Cost Centre Category from the drop down list provided.">!</asp:CustomValidator>
How can I have 2 Cascading Drop Down Lists for the same Drop Down List?here is my problemi have 3 drop down lists read from database1- Schools List 2- Classes List3- Teachers ListEvery School will have more than 1 Class and more than 1 TeacherWhat I want is when user select a School from Schools Drop Down List then BOTH (Classes and Teachers) should be refreshed based on the School Drop Down List
my one table consists of fields (id, flying from, flying to). thus i have one drop down for flying from and another drop down for flying to. i'm hoping to cascade them so 2nd drop down values are dependant on the values from 1st drop down. is it possible to do this using a single table? or must i use two tables and link the id's from both? and do i write anyting in the SelectedIndexChange event? the sqldatasource code looks like this:Flying From:
I am currently building a web site and I utilize cascading drop down lists. I am having difficulty clearing two of my drop downs. The application is utilizing Visual Basis. Here is what I found through my research but they are not resetting my drop downs after a post back:
i followed this tut http://www.ajaxprojects.com/ajax/tutorialdetails.php?itemid=554 for cascading drop downs, but i changed the sql connections for my linq datasource. VS2010 is showing no errors in my code and the page loads fine too, but the two drop down lists are emptycan anyone scan there eyes over it and see if theres any reason why it shouldnt be working?my code is the same as the tuts apart from it uses LINQ instead of SQL
I have 3 dropdown lists. All 3 are using the same generic list for there items. I am using C# as the code behind. The code below shows the DTO list i am using and how I'm adding them to the drop downs...
I've been trying to get this to work for weeks. I am trying to use a cascading drop down to populate drop down lists. The service method is working as i'm able to view the data in the browser but when i run the application the drop down list is empty. see below for the service method.
was having some trouble setting up databound cascasding dropdownlists. As a workaround I decided to go down the route of placing three standard dropdownlists in an updatepanel - I cant find any info to help to do this.Can anyone help with what I need??? I need three dependant dropdown lists to refresh after selection of the parent one without refreshing the whole page. Im using VS2005 .net 2.0 and I have installed the ajax toolkit.
I have a Cascading drop down list that is working fine to load the correct lists however I would like to have the last one initiate a query and display a datagrid on the same page containing the results of the query. Without Ajax involved this seems rather easy by using autopostback on the drop downs. If I could do it through Ajax that would be great but I can settle with having the page to reload to display the data. Right now I'm not sure how to do either. I enabled autopostback on the last drop down and wrote a method for it but I get an error at runtime saying:
I have 3 drop down boxes, created using the HTML select tag. On page load, the first box has a few names. Now, when I click on one of the names in the first box, some more names should appear in the second and when I click on a name in the second box, some more names should appear in the third box. How can I achieve this using AJAX? I have to use ASP.Net and MS SQL Server only. I'm a complete noob to AJAX and I've been educating myself about it, but nothing's working out. I've been looking for the code for close to a week. I looked up w3schools.com, but when I tried that code, it didn't work. Please help me out and please tell me step by step, the things required in order to make it work, and what goes where. I have a deadline that is fast approaching and am at my wit's end trying to make it work.
I am using 2 cascading drop down lists in my website. When i test my app on localhost both work perfectly. But after uploading my webapp on the hosting server i receive the following error :
I have several cascading drop down in my website which work fine. The problem is that i know need to use cascading drop down in a modal popup. The first list is populated but the subsequent lists are not being populated.
Does anyone know if it is possible to have Cascading DropDown Lists which are based on the selected value of more than a single list. Example - I have four tables in a database as follows:
Product PartA PartB PartC
The items in Product are made up by one record from each of the other three tables (PartA + PartB + PartC = Product). What I wish to do is have 3 Cascading DropDown lists which refer to the three individual parts which can be used to select items fromt he Product table.
The first two work no problem but when it comes to the third the list is condition on only items which have the selects of both the first two lists.
I have a page that has a cascading drop down. It works perfectly when I start with an empty page and populate data to save a new row in a db table. However, when I try to load an existing row to the page, the parent is populated, but the child and cdd are not populated. During the load, I set the ccd.selectedvalue to a valid value, but by the time the page is rendered, there is no selection. I am sure it is something simple, but just don't see it.
I have a problem with 3 cascading drop downs. They are on a content page, so I have a Master Page as well. They work just fine but once the user saves the data and then comes back to the same page, I would like to show them what was previously saved. How can I pre-select items in the drop downs that I get from my SQL server db? I tried jquery, javascript, vb code behind and no luck so far. I'm sure i'm doing something wrong. Here is my code:
I've been trying to send my webservice a contextkey for the first drop down. When I debug the webservice, and I manually enter a context key, i get the correct values back with the value that equals my context key having <isDefaultValue>True</isDefaultValue>.
Aspx page:
[Code]....
WebService (part of it that gets data for my first drop down):
[Code]....
[Code]....
Javascript (tried to set the context key here)[Code]....
I'm seeking to develop Web page that has multiple Drop Down List (3 controls) bind with my database and these controls support AJAX and access my database using LINQ
e.g, when I select one of the control name : Class, then It should access the database then, display the department in this class in the next Drop Dawn List in the next control - ALL this without PostPacking this page and access the my database using LINQ.
how do i create a cascading drop-down list without using ajax controls...i am using queries and the language i am using is C# I have a client and a project database....when i choose a client name in the dropdownlist....only the project names associated with that client should appear in the next dropdownlist
I seem to be having a problem loading a gridview using 2 cascading drop down lists. Before I implemented the Ajax cascading drop down list extenders and I just had regular drop down list the gridview that is supposed to load when users choose the appropriate data from the 2 drop down list appears when the submit button was triggered.
[Code]....
When the button event is triggered it looks for the specific value in the second drop down list and calls a specific stored procedure to load the gridview. Now after implementing the cascading drop down lists the page just posts back - there are no errors whatsoever.
