Could you give some simple example of how to create form that consists of only dropdownlist?
I want to use it to create admin-side user management to assign users to one role, with aspnet mvc simplemembership. I mean step by step:
- list all registered users (DONE)
- next to their nicks show dropdown list; selected value is user's current role using
Roles.AddUserToRole(item.UserName, "RoleName");
by changing dropdown value assign user to new role (overwrite old one) with ajax (don't reload page, just show for few seconds success/error status)
Anyway, I'd like similar example how to do it, it doesn't have to be code I exactly need to produce.
Many thanks in advance.
$("#dropdown").on("change keyup", function() {
var selected = $(this).val();
$.post("/Controller/AssignRole", {selectedRole: selected}, function(data) {
//data is the value returned by your action method.
//example: partial view, or status message
$("#status").html(data); //success message
});
});
Related
I have view for showing Member details. Inside there is an EditorFor element which represents subjects taken by the member.
#Html.EditorFor(m => m.Subject)
Inside the editor template there is a Html.DropDownListFor() which shows the selected subject and button to delete that subject
I am using an Html.DropDownListFor element as :
#Html.DropDownListFor(m => m.SubjectID, Enumerable.Empty<SelectListItem>(), "Select Subject",
new { #class = "form-control subjects" })
The second parameter(source) is set empty since I want to load the source from an AJAX request; like below:
$.getJSON(url, function (response) {
$.each(response.Subjects, function (index, item) {
$('.subjects').append($('<option></option>').text(item.Text).val(item.ID));
});
// code to fill other dropdowns
});
Currently the html loads before the dropdowns are filled. So the values of all subject dropdowns are set to the default "Select Subject". Is there a way around this or is it the wrong approach?
Note: There are a number of dropdowns in this page. That's why I would prefer to load them an AJAX request and cache it instead of putting in viewModel and filling it for each request.
** EDIT **
In AJAX call, the action returns a json object containing dropdowns used across all pages. This action is decorated with [Output Cache] to avoid frequent trips to server. Changed the code in $.each to reflect this.
You can initially assign the value of the property to a javascript variable, and use that to set the value of the selected option in the ajax callback after the options have been appended.
// Store initial value
var selectedId = #Html.Raw(Json.Encode(Model.Subject.SubjectID))
var subjects = $('.subjects'); // cache it
$.getJSON(url, function (response) {
$.each(response, function (index, item) {
subjects.append($('<option></option>').text(item.Text).val(item.ID));
});
// Set selected option
subjects.val(selectedId);
});
However its not clear why you are making an ajax call, unless you are generating cascading dropdownlists which does not appear to be the case. What you doing is basically saying to the client - here is some data, but I forgot to send what you need, so waste some more time and resources establishing another connection to get the rest of the data. And you are not caching anything despite what you think.
If on the other hand your Subject property is actually a collection of objects (in which case, it should be Subjects - plural), then the correct approach using an EditorTemplate is explained in Option 1 of this answer.
Note also if Subject is a collection, then the var selectedId = .. code above would need to be modified to generate an array of the SubjectID values, for example
var selectedIds = #Html.Raw(Json.Encode(Model.Subject.Select(x => x.SubjectID)))
and then the each dropdownlist value will need to be set in a loop
$.each(subjects, function(index, item) {
$(this).val(selectedIds[index]);
});
If your JSON tells you what option they have selected you can simply do the following after you have populated your dropdown:
$('.form-control.subjects').get(0).selectedIndex = [SELECTED_INDEX];
Where [SELECTED_INDEX] is the index of the element you want to select inside the dropdown.
i am using material UI dropdown component and trying to run a callback function only when user fills all the form and submits the form. On the call back function i intend to collect all the form field and generate url to call to api.
My problem is that i can not use onChange as stated solution in #560 as i want to collect all the detail only when user clicks the submit button. It is also weird that at the moment, i am able to get value of all the other form element like slider, textfield which uses material-ui but only dropdown does not seem to be working.
My call back function:
handleFilter: function(event){
event.preventDefault();
var location = this.refs.location.getValue();
var posted_date = this.refs.posted_date.getValue();
var radius = this.refs.distance.getValue();
var salary = this.refs.salary.getValue();
var jobtype = this.refs.jobtype.getValue();
console.log(jobtype);
}
In the above function "location, posted_date, radius, salary" returns value but "jobtype" which happens to be dropdown does not seem to return any value. It returns this error in console:
"Uncaught TypeError: this.refs.jobtype.getValue is not a function"
Here is my dropdown component :
<DropDownMenu menuItems={menuItems} ref="jobtype" />
May not be the right way but i figured out that
console.log(this.refs.jobtype) (jobtype is the refs value of dropdown in my case)
was giving the following result.
R…s.c…s.Constructor {props: Object, context: Object, state: Object, refs: Object, _reactInternalInstance: ReactCompositeComponentWrapper}
Inpecting it i found value of payload index (index number of selected item) inside state object within "selectedIndex" property. I used following code to access the selected index:
var jobtype = this.refs.jobtype.state.selectedIndex;
If there is a better way to do this please suggest.
Can someone please help me i want to update a database record by using the dropdownlistbox,
so when i select an option from the dropdown the database is updated with that value for that record, without having to click a submit button using codeigniter.
I know the best way to go about this is with AJAX
Yeah AJAX can make it work, and doing it with jQuery can make it a lot easier. You can add an event listener to your dropdown list, listening to a change in its value:
$("#the-dropdown-list").change(function() {
var value = $(this).attr("value");
$.ajax({
url: "path/to/controller/action/",
type: "POST",
data: {value: value},
success: function() {
// whatever you want to do after
}
});
});
This will detect a change in the dropdown list value, and then send it to the controller action given in url in $.ajax object. After that you can just update the database record like you would usually do. In the controller, the new value can be obtained using $_POST['value'], since we defined type to be POST and the different values to be passed to controller action are in the data.
I have a page of products and for each of them, I want to have a form that uses AJAX to update the session. I've done this bit - just providing background.
I use the product's ID to create a different form class and name for each form, so each form is called something like this_form_name_567 and the next would be this_form_name_568 and so on.
There is a submit button per form. I'm having trouble figuring out
Which event is best to use so that the correct form will be identified when a submit button is clicked?
Once clicked, how to then make sure the correct value is taken from a hidden field (unique ID) within the submitted form so that I can populate a line of code such as:
$.post("compare_response.php", {compare_this: $("#compare_this").val()}, function(data){
}
You can use the .closest tree traversal method to get the form in which the button of interest is nested:
$("input[type=submit]").click(function() {
alert($(this).closest("form").attr("id"));
});
or even simpler, just get the element's form property :)
$("input[type=submit]").click(function() {
alert(this.form.id);
});
You can try it out here.
You can get the form you are submitting like this:
$('form').submit(function() {
var yourForm = $(this);
var hiddenValue = $(this).find('input[type=hidden]').val();
});
Of course you can get the hidden value differently, or if you have more than one hidden you'll have to give a little more information about it.
I have a basic checkbox click function that only allows the user to click only one checkbox within each fieldset (there are four fieldsets each containing numberous checkboxes:
$(document).ready(function(){
$('input[type=checkbox]').click(function(){
// get the fieldset class
var fieldset = $(this).parents('fieldset').attr('class');
// set the number of checked
var numChecked = $('.'+fieldset+' input:checked').size();
// if more than 1
if(numChecked > 1){
alert('Please select only one option per breakout session.')
$(this).attr('checked',false);
}
});
Then I have a submit function on the form that will confirm that at least one checkbox is selected before posting the form:
$('form[name=mainForm]').submit(function(){
var error = '';
// loop through each fieldset
$('fieldset',this).each(function(){
// set the number of checked for this fieldset
var numChecked = $('input:checked',this).size();
// if none are checked
if(!numChecked){
// set the error var
error = 'At least one of your time sessions has no checkbox selected!';
// add class to show user
$(this).addClass('errorSessions');
}
else{
$(this).removeClass('errorSessions');
}
});
// if any errors, show them and don't allow the form to be submitted
if(error.length){
alert(error);
return false;
}
$("#mainForm").validate();
The form validates perfectly and everything happens flawlessly the first time around. The problem is that if you submit the form, the validation occurs and it gives the error "At least one of your time sessions has no checkbox selected!" - at that point if you proceed to select multiple checkboxes within a given fieldset that was not initially checked, it will ignore the checkbox click function and allow you to select more than one checkbox in a fieldset.
Can someone please help with this?
Okay, I figured it out. The error has to do with the script adding the class 'errorsessions' to the fieldset which changes the unique classname of the fieldset. By adding a unique id to each fieldset and then changing the script to reference .attr('id'); instead of .attr('class'); the issue resolved and the on click alert function resumed after the class was added.
Do you consider using radio buttons as they are there for single selection? This way you don't have to check for multi selection as it isn't possible for select more than one radio button in given group.