Using a variable as JQuery selector - javascript

I have a dropdown/select menu that shows and hides various divs based on what the user has selected. Within each div there is another dropdown/select menu that I would like to also trigger an action on change.
As this div is given an ID dynamically I am struggling to figure out how to select the required dropdown/select menu.
Here is the jQuery code:
$(document).ready(function(){
$("#category").change(function(){
var category = $("#category").val();
var box = $('#'+ category);
$('.class-name').hide();
box.show();
}) ;
var category = $("#category").val();
var selector = 'selector_'+category;
$("#"+selector).change(function(){
alert('Do something');
});
});
And some simplified HTML:
<select id='category'>
<option value='0'>1</option>
<option value='1'>2</option>
<option value='2'>3</option>
</select>
<div class='box class-name' id='1'>
<select id='selector_1'>
<option value='1'>One</option>
<option value='2'>Two</option>
</select>
</div>
<div class='box class-name' id='2'>
<select id='selector_2'>
<option value='1'>One</option>
<option value='2'>Two</option>
</select>
</div>
<div class='box class-name' id='3'>
<select id='selector_3'>
<option value='1'>One</option>
<option value='2'>Two</option>
</select>
</div>
The divs show and hide as desired, but I can't for the life of me get the alert('Do Something'); to trigger which I assume is a problem with how I am trying to select the dropdown/select menu.
All help much appreciated!
Cheers, DB.

You need chain the changes. The way you made it, the code runs all at once, meaning:
When document ready, do:
Set onChange in the #category element
Find category current value (right now, none is selected, so value is undefined)
Set selector to "selector_" + undefined
Find element with id selector, since there's no element with this id, no change is defined.
Try this, instead:
$(document).ready(function() {
var categoryField = $("#category");
categoryField.change(function() {
var category = categoryField.val();
var box = $('#'+ category);
$('.class-name').hide();
box.show();
var selector = 'selector_'+category;
$("#"+selector).change(function() {
alert('Do something');
});
});
});

var category = $("#category").val();
Category is empty on page loaded.
Simple solution:
$(".box select").change(function(){
alert('Do something');
});

I checked, it's working
$("#category").change(function(){
var category = $("#category").val();
var box = $('#'+ category);
$('.class-name').hide();
box.show();
var s = $(box).find('select');
$(s).bind("change", function() {
alert("Do something");
})
})

Within each div there is another dropdown/select menu that I would
like to also trigger an action on change.
It seems you are looking to trigger event when there is a change in the dropdowns wrapped by the div
If it is so you can use jquery wild card selector
In your case all those select elements have same prefix id.
So $("[id^=selector_]") will response to to any select box which have such string as prefix
$("[id^=selector_").change(function(event){
$("#demoUp").text($(this).context.value);
});
Check this JSFIDDLE. The placeholder will be updated by the value of selectd option

To point you have change the id on document page ,use below
$(document).on("change",$("#"+selector),function(){
alert('Do something');
});

Try this:
$(document).ready(function(){
$("#category").change(function(){
var category = $(this).val();
$('.class-name').hide();
$('#'+ category).show();
$("#selector_"+category).change(function(){
alert('Do something');
});
}) ;
});

Related

Get value from dynamically created droplist

I my code I create droplists and hidden field for each of them to be able to catch selected value in code behind. I do have a problem set hidden value to the value of selected item in droplist probably because I am not able to create correct selector.
Name of my droplist are dropTypeXXY where XX stands for two alphanumeric characters and Y stands for number for example.
dropTypeU19, dropTypeBB22, dropTypeAG71
hidden fields for them are hdnY where Y stands for number
hdn9, hdn22, hdn71
In both cases these values are IDs of given html elements.
My question is how can I assign list item value to hidden field when droplist selection is changed.
My jQuery
$(document).ready(function(){
$("select[id^='dropType']").on("change",function () {
alert("HI"); //Just to test the selector itself.
});
});
Edit:
My problem is that the selector is not working and alert is not even called. Whey I try to apply similar approach to droplist that I create in code behind it works but not for droplists created by jQuery.
var list = $("<select id = dropType" + response.d[i].TypeId+ i + "/>");
var valueField = $("<input type='hidden' id = 'hdn" + i + "' name ='hdn" + i + "' value=-1 />");
...
$("#<%=grdUsers.ClientID%>").after(list, valueField);
I create them based on AJAX call. I am able to display them in console and display them to user and even give them items but I am not able to run .change() event on them.
Sorry I did not mentioned it earlier.
This doesn't work for them as well. Is there a problem with html tags that are not part of DOM from the beginning of page life?
$("select").on("change", function () {
alert("hi");
});
Edit 2
I looks like my answer lies here. It actually works and alert is raised. Thank you very much guys I'll try to implement the data-target and class trick.
With Dynamically created controls it is easier to select them by class since you cannot use ClientID. Go give them a unique CssClass in code behind when creating the Control.
DropDownList ddl = new DropDownList();
ddl.Items.Insert(0, new ListItem("Value A", "0", true));
ddl.Items.Insert(1, new ListItem("Value B", "1", true));
ddl.CssClass = "DynamicDropDown";
Panel1.Controls.Add(ddl);
Now you can select them with jQuery like this
$(document).ready(function () {
$(".DynamicDropDown").on("change", function () {
alert("HI");
});
})
You can use a class selector ("select" for example) (instead of an id) and add an attribute data-target in your html that say which hidden field is linked to this droplist.
And your js can be something like :
$(document).ready(function(){
$("select.select").on("change",function () {
var $target = $($(this).attr("data-target"));
$target.val($(this).val());
});
});
Or you can also use DOM navigation to find the hidden field without any id if you know the structure of your code and if it's always the same.
Pseudo html code :
<div>
<select>...</select>
<input type="hidden">
</div>
jQuery :
$(document).ready(function(){
$("select").on("change",function () {
var val = $(this).val();
$(this).parent().find("input").val(val);
});
});
You can do it by adding class to a name you specify.
<select id="dropTypeU19" class="cls-name">
<option value="a">a</option>
<option value="a1">a</option>
</select>
<select id="dropTypeBB22" class="cls-name">
<option value="b">a</option>
<option value="b1">a</option>
</select>
<select id="dropTypeAG71" class="cls-name">
<option value="c">a</option>
<option value="c1">a</option>
</select>
<input type="hidden" id="hdn19" />
<input type="hidden" id="hdn22" />
<input type="hidden" id="hdn71" />
<script>
$(function () {
$("select.cls-name").change(function () {
var selectId = $(this).attr("id");
var selectValue = $(this).val();
var hiddenId = "#hdn" + selectId.slice(-2);
$(hiddenId).val(selectValue);
alert($(hiddenId).val());
});
});
</script>
OR:
$("select[id^='dropType']").change(function () {
var selectId = $(this).attr("id");
var selectValue = $(this).val();
var hiddenId = "#hdn" + selectId.slice(-2);
$(hiddenId).val(selectValue);
alert($(hiddenId).val());
});

Jquery select variable by id

I am trying to get the content of a select option which is specified by the selected options.
I can get the selected options to tell me the data-parent but I can't use that to get the text of the parent option.
<select id="addCatSelectCats" multiple="multiple">
<option id="Cat55" data-parent="5">Parent Cat</option>
<option id="Cat357" data-parent="55">Sub Cat</option>
</select>
$(document).on('change', '#addCatSelectCats',function() {
$("#addCatSelectCats option").each(function(){
if($(this).is(':selected')){
var dataparent = $(this).attr('data-parent');
if(dataparent > 0){
var parent = $('#Cat'+dataparent).text();
alert(parent);
}
}
});
});
Where am I going wrong?
You could do with a little less code
$(document).on('change', '#addCatSelectCats',function() {
var parent = $("#addCatSelectCats option:selected").text();
alert(parent);
});

jQuery getting selected option of dynamically rendered dropdown list

I am working on an MVC + jQuery project, I am creating dropdown list on runtime. After rendering while submitting form through jQuery, I am trying to get selected value. Drop down is rendered and working fine
Also I can check in source code. I am trying to get dropdown list by
$('#Monday_Periods').children('.PeriodRow').each(function () {
var elements = $(this).html();
var found = $('.Subject', elements);
});
I found all objects in variable found, and I can see it in Chrome debug
But after this I am unable to get selected value. As you can see in debug mode that no option is selected. I tried to get by val or text but no luck. Anybody can tell me that how I can get selected value
$(this).html(); is loosing the reference to the DOM (html() returns a String, not a DOM node).
Try to modify in:
var elements = $(this);
var found = $('.Subject', elements);
found.each(function(el){
console.log($(this).val());
}
or use directly (you already have an id on it!):
$('#subject1').val();
EDIT: SNIPPET ADDED
function printResults(){
$('#Monday_Periods').children('.PeriodRow').each(function () {
var elements = $(this);
var found = $('.Subject', elements);
found.each(function(el){
console.log($(this).val());
});
});
}
$('#print-results').click(printResults);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<form id="Monday_Periods">
<div class="PeriodRow">
<select class="Subject">
<option value="none">-- Select Subject --</option>
<option value="1">Biology</option>
<option value="2">Physics</option>
</select>
<select class="Subject">
<option value="none">-- Select Subject --</option>
<option value="1">Biology</option>
<option value="2">Physics</option>
</select>
</div>
<button type="button" id="print-results">PRINT RESULTS</button>
</form>

How to replace a select tag when sibling is changed

I have three (cascading) select tags that appear one after another in a div. The html for them only differ in the options. The name and ids of the select are the same.
<div class="dad">
<select id="foo" name="foo[bar]" value="myVal">
...
<option value="343">boom</option>
...
</select>
<select id="foo" name="foo[bar]" value="myVal">...</select>
<select id="foo" name="foo[bar]" value="myVal">...</select>
</div>
The behavior I need is when a select is changed, an ajax call is made which provides the data (markup) for the next select. The data I get back which is markup a select and it's options is fine but am having issues replacing the next select.
$('select#foo').live("change", function() {
var optionSelected = $('option:selected', this);
var selID = optionSelected.val();
$.post('/postUrl?data=selID', function(data) {
// need to replace the second select
});
...
Usually I would have the id or class of the select I need to replace and would be easy. THe issue here is since all three select have the same id and name how can i identify the select after the one that is selected? Thanks.
You can do something like this..
$('select#foo').live("change", function() {
var optionSelected = $('option:selected', this);
var selID = optionSelected.val();
var nextSelect = $(this).next();
$.post('/postUrl?data=selID', function(data) {
// do action with nextSelect
nextSelect.doSomething;
});

Jquery/Javascript link $(this) to an element in a different div?

I've got a multiple select that I want to use to pick which elements show up in an HTML template window. So I have several options that I want to iterate over, and based on whether it's been selected, make the preview elements visible or hidden.
I'm going for something like this:
$('#area_select option').each(function(i){
if($(this).is(':selected')){var $css = {'visibility' : 'visible'}}
else{var $css = {'visibility' : 'hidden'}}
$(??????).css($css);
});
As you can see, I'm just iterating over each option (I'm pretty sure that syntax works) in my area_select menu, but I don't know how to make the css get applied to the corresponding piece.... how can I reference my preview elements via my options?
An easier way to go is to call .val() on the multiple select. That returns an array of selected values that you can iterate over.
var array = $('#area_select').val()
$.each(array, function(i,val) {
// your code
});
So as far as showing the elements is concerned, it would depend on what type of data is stored in the value of the select options.
For an ID, do this:
$(selectorForCollection).css('visibility','hidden');
var array = $('#area_select').val();
$.each(array, function(i,value) {
$('#' + value).css('visibility','visible');
});
Or if they are class names, do this:
$(selectorForCollection).css('visibility','hidden');
var array = $('#area_select').val();
$.each(array, function(i,value) {
$('.' + value).css('visibility','visible');
});
Give each of the options a name corresponding to the ID of the correct piece.
e.g.
<select>
<option value="whatever">Whatever</option>
<option value="whatever2">Whatever 2</option>
</select>
Then each of you elements will be contained in a a div like this:
<div id="whatever-preview">
<!-- Whatever -->
</div>
Then your Javascript
$('#area_select option').each(function(i){
if($(this).is(':selected')){var $css = {'visibility' : 'visible'}}
else{var $css = {'visibility' : 'hidden'}}
var div_name = "#" + $(this).attr('value') + "-preview";
$(div_name).css($css);
});
Give each option an id referencing the id of the corresponding element in the preview window.
for instance:
<option id="option-1">This turns on the first option element in the preview window</option>
<option id="option-2">This turns on the first option element in the preview window</option>
and give the preview window elements similar-ending ids:
<div id='window-1'>corresponding window preview element</div>
Then in the javascript:
$("#window-" + $(this).attr('id').split('-')[1]).css($css);
First, give the elements to hide or show the same class but id's matching the options values:
<div class="something" id="val_1">content1</div>
<div class="something" id="val_2">content2</div>
<div class="something" id="val_3">content3</div>
<div class="something" id="val_4">content4</div>
<select id="area_select">
<option value="val_1">val 1</option>
<option value="val_2">val 1</option>
<option value="val_3">val 1</option>
<option value="val_4">val 1</option>
</select>
then, when the select choosen option changes hide all the stuff and show the selected
$('#area_select').change( function(){
var val = $(this).val();
$('.something').hide();
$('#'+val).show();
return false;
});

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