Generating text based on selected option in HTML using JavaScript - javascript

I am trying to create a site where you select an option from a dropdown list called contactOptions. The options has values ranging from 0 to 8. When the option is selected, I wish for text to appear underneath -- this text is contained within div tags with ID's such as #contact0 for the text corresponding to option 0. These ID's all have display: none by default. I have some JavaScript (below) -- the select tag in my html includes the line onchange = "sortForm()". Unfortunately, the script does not do anything -- the #contact0 remains invisible.
function sortForm() {
var selection = document.getElementById("contactOptions");
var selectedValue = selection.options[selection.selectedIndex].value;
for (var i = 0; i <=8; i++) {
var subobjContact = document.getElementById("contact" + i);
if (i == selectedValue) {
subobjContact.style.display == "block"
} else {
subobjContact.style.display == "none"
}
}
}

Use single equal sign
subobjContact.style.display = "block"
and
subobjContact.style.display = "none"

Related

how to append array to drop down navigation bar and disable one option in it

I have a navigation bar with 5 elements, drop down menu field, textarea and another text field. what i need:
to disable all navigation bar elements except Home when document be ready. then when i blur the text field remove attr disabled from them and activate again.
to separate all the values in the dropdown menu field started with 001 in additional drop down menu under the master in the navigation bar without the third part in the line (url) , append values started with 002 in additional drop down menu under CSS without (url) and 003 under javascript also without (url) .
when user click in logout option under home window close.
this is Demo:https://jsfiddle.net/ov43ebko/1/
$(document).ready(function(){
$('.css,.jscript,.jquery').attr('disabled','disabled');
$('.logOut').click(function(){
window.close();
});
// to split lines based on semicolon.
function check(){
var lines = $('.hiddenText textarea').val().split(/\n/);
var texts = [];
for (var i=0; i < lines.length; i++) {
texts.push($.trim(lines[i]));
}
for (var i=0; i < texts.length; i++) {
var removed1 = texts[i].split(';');
$(".masters").append($("<ul><li>").text(removed1[0]));
$(".css").append($("<ul><li>").text(removed1[1]));
$(".jscript").append($("<ul><li>").text(removed1[2]));
}
}
// to split dropdown menu choices to lines.
function c1() {
var resultLines = $('.filledField').find('option').size();
var textArea ="";
for (var i = 1; i <= resultLines; i++) {
var xItem = $('.filledField').find('option:nth-child(' + (i) + ')').text();
textArea += xItem ;
//code to split xItem into individual variables
}
$('.hiddenText textarea').val('');
$('.hiddenText textarea').val(textArea);
check();
}
$(".field").blur(function(){
$('.css,.jscript,.jquery').prop("disabled", false);
c1();
});
});
I hope that this is what you wanted to achieve.
1. to disable all navigation bar elements except Home when document be ready. then when i blur the text field remove attr disabled from them and activate again.
For this, have given pointer-events:none to disable li tags as they can't be disabled using attribute disabled.
$('.css,.jscript,.jquery').css('pointer-events', 'none');
And then enabled it by setting css back to all.
$(".field").blur(function() {
$('.css,.jscript,.jquery').css('pointer-events', 'all');
c1();
});
2. to separate all the values in the dropdown menu field started with 001 in additional drop down menu under the master in the navigation bar without the third part in the line (url) , append values started with 002 in additional drop down menu under CSS without (url) and 003 under javascript also without (url) .
I may have misunderstood this point but here is what I think you wanted. Have checked first parameter value and accordingly appended the second parameter value in ul under drop down menu.
if (parseInt(removed1[0]) == 1) {
$(".masters ul").append($("<li></li>").text(removed1[1]));
} else if (parseInt(removed1[0]) == 2) {
$(".css ul").append($("<li></li>").text(removed1[1]));
} else if (parseInt(removed1[0]) == 3) {
$(".jscript ul").append($("<li></li>").text(removed1[1]));
}
Please refer this fiddle.

How do I filter an unorderded list to display only selected items using Javascript?

I have this JSFiddle where I am trying to make it so that the items in an unordered list are visible only if the option selected in a drop down matches their class. List items may have multiple classes, but so long as at least one class matches, the item should be made visible.
The Javascript looks like this:
function showListCategories() {
var selection = document.getElementById("listDisplayer").selectedIndex;
var unHidden = document.getElementsByClassName(selection);
for (var i = 0; i < unHidden.length; i++) {
unHidden[i].style.display = 'visible';
}
};
The idea is that it gets the current selection from the drop down, creates an array based on the matching classes, then cycles through each item and sets the CSS to be hidden on each one.
However, it's not working. Can anyone tell me where I'm going wroing?
Note that I haven't yet coded the "show all" option. I think I'll probably be able to figure that out once I have this first problem solved.
In your fiddle change load script No wrap - in <head>.
Just change your function like following
function showListCategories() {
var lis = document.getElementsByTagName('li');
for (var i = 0; i < lis.length; i++) {
lis[i].style.display = 'none';
}
//above code to reset all lis if they are already shown
var selection = document.getElementById("listDisplayer").value;
lis = document.getElementsByClassName(selection);
for (var i = 0; i < lis.length; i++) {
lis[i].style.display = 'block';
}
};
and in css it should be none not hidden
.cats, .rats, .bats {
display: none;
}
If you want to show all li when showAll is selected, add all classes to all lis.
You have a few things going on. First, your fiddle is not setup correctly, if you open the console you'll see:
Uncaught ReferenceError: showListCategories is not defined
This means that the function doesn't exist at the point you attach the event or that the function is out of scope, because by default jsFiddle will wrap your code in the onLoad event. To fix it you need to load the script as No wrap - in <body>.
Second, there's no such thing as a display:visible property in CSS. The property you want to toggle is display:none and display:list-item, as this is the default style of <li> elements.
Now, to make this work, it is easier if you add a common class to all items, let's say item, that way you can hide them all, and just show the one you want by checking if it has a certain class, as opposed to querying the DOM many times. You should cache your selectors, it is not necessary to query every time you call the function:
var select = document.getElementById('listDisplayer');
var items = document.getElementsByClassName('item');
function showListCategories() {
var selection = select.options[select.selectedIndex].value;
for (var i=0; i<items.length; i++) {
if (items[i].className.indexOf(selection) > -1) {
items[i].style.display = 'list-item';
} else {
items[i].style.display = 'none';
}
}
}
Demo: http://jsfiddle.net/E2DKh/28/
First there is no property in Css like display:hidden; it should be display: none;
here is the solution please not that i am doing it by targeting id finished
Js function
var selection = document.getElementById("listDisplayer");
var list = document.getElementsByTagName('li');
selection.onchange = function () {
var value = selection.options[selection.selectedIndex].value; // to get Value
for (var i = 0; i < list.length; i++) {
if (list[i].className.indexOf(value) > -1) {
list[i].style.display = "list-item";
} else {
list[i].style.display = "none"
}
}
}
css Code
.cats, .rats, .bats {
display: none;
}
JSFIDDLE
You have many things wrong in your code and a wrong setting in the jsFiddle. Here's a working version that also implements the "all" option:
Working demo: http://jsfiddle.net/jfriend00/5Efc5/
function applyToList(list, fn) {
for (var i = 0; i < list.length; i++) {
fn(list[i], list);
}
}
function hide(list) {
applyToList(list, function(item) {
item.style.display = "none";
});
}
function show(list) {
applyToList(list, function(item) {
item.style.display = "block";
});
}
function showListCategories() {
var value = document.getElementById("listDisplayer").value;
var itemList = document.getElementById("itemList");
var items = itemList.getElementsByTagName("li");
if (value === "all") {
show(items);
} else {
// hide all items by default
hide(items);
show(itemList.getElementsByClassName(value));
}
}
Changes made:
You have to fetch the .value of the select to see what the value was of the option that was picked. You were using the selectedIndex which is just a number.
A common technique for displaying only a set of objects is to hide all of them, then show just the ones you want. Since the browser only does one repaint for the entire operation, this is still visually seamless.
When finding items that match your class, you should be searching only the <ul>, not the entire document. I added an id to that <ul> tag so it can be found and then searched.
To save code, I added some utility functions for operating on an HTMLCollection or nodeList.
Tests for the "all" option and shows them all if that is selected
Changed the jsFiddle to the Head option so the code is available in the global scope so the HTML can find your change handler function.
Switched style settings to "block" and "none" since "visible" is not a valid setting for style.display.

Javascript: Loop through array while adding CSS styling

I have a for loop.
In the loop there is an if statement that adds an error css style if the dropdown is found empty.
My problem is that the loop only loops 3 times then stops when it is supposed to loop 15 times.....and i do not know why.
The loop alone works fine, but but when i add the if statement, that's when it becomes weird.
Help.
here is my loop
//add all the id's in an array. array size is 15
var drop_down=["Cars_chassis","Cars_model".....];
for (var i = 0; i < drop_down.length; i++) {
//check if dropdown is empty
if(document.getElementById(drop_down[i]).value == ""){
//change the color of border
$('#'+drop_down[i]).css('border-color' , '#dddcdc');
}
}
I would suggest adding a CSS class to each one of these elements instead of specifying their id. Why manage all of those ids when one class can do the trick?
<select id="Cars_chassis" class="bordered-select"></select>
<!-- Add class to other 15 -->
At this point you could statically define a style for these drop downs in CSS.
.bordered-select{
border-color: #DDDCDC;
}
Or set the style on the elements using the class selector. It appears your using jQuery so the following example would work.
$(".bordered-select").css('border-color', '#DDDCDC');
If you only need to highlight those without a value the following would remove those without a value from the matched set of elements:
$(".bordered-select").filter(function(){
return $(this).val() == "";
}).css("border-color", "#DDDCDC");
Working Example: http://jsfiddle.net/v4hQz/
var drop_down=["Cars_chassis","Cars_model".....];
for (var i = 0; i < drop_down.length; i++) {
//check if dropdown is empty
if( $('#' + drop_down[i]).value == ""){
//change the color of border
$('#'+drop_down[i]).css('border-color' , '#dddcdc');
}
}
OR you can try
var drop_down=["Cars_chassis","Cars_model".....];
var contents = $('#' + drop_down[i]);
for (var i = 0; i < drop_down.length; i++) {
//check if dropdown is empty
if( $(contents[0]).value == ""){
//change the color of border
$('#'+drop_down[i]).css('border-color' , '#dddcdc');
}
}
document.getElementById(drop_down[i]); //returns a HTML DOM Object
var contents = $('#' + drop_down[i]); //returns a jQuery Object
You can try replace the if (javascript) to if (jquery syntax)

How do I add items to multiple drop down lists at the same time with Javascript in Razor?

I'm creating an MVC form, and I have multiple checkboxes and two drop down lists. I have figured out how to populate the first DDL based on what boxes are checked (i.e. empty at the beginning, checking boxes fills the items). However, I want to add another DDL that has the same items and populates in the same manner. My code looks like this:
<script type="text/javascript">
function checkedToggle(value, checked) {
x = document.getElementById("filter1");
y = document.getElementById("filter2");
if (checked == true) {
var option = document.createElement("option");
option.text = value;
x.add(option, null);
y.add(option, null);
}
else {
for (i = 0; i < x.length; i++) {
if (x.options[i].value == value) {
x.remove(i);
y.remove(i);
}
}
}
}
</script>
The else statement obviously removes an item from the list once you uncheck the box.
Now, when you click a check box, rather than adding the item to both lists, it only adds to the second one, and I'm not exactly sure why. Any advice?
You need to create two elements, since in your code you just move the first DOM element to the second select.
var option = document.createElement("option");
var option2 = document.createElement("option");
option.text = value;
option2.text = value;
x.add(option, null);
y.add(option2, null);

making text boxes visible

I have a drop down if i click it will retrieve values from db.If thre are 4 values that has to pass into text box and make it visible.If 5 values then 5 values has to get visible.There will be a count if 4 boxes count has to get into 5th box.if 5 values then count has to get int0 6th box.
How do i do it?
If the text boxes are in the markup and you've just hidden them (e.g., style="display: none"), you can show them again by setting their style.display property to "":
textBoxElement.style.display = "";
For example, here's a button click handler that looks for a text field to show and shows it; if there aren't any more to show, it hides the button:
var myForm = document.getElementById('myForm');
document.getElementById('btnShowField').onclick = function() {
var index, field, foundOne, foundMore;
foundOne = foundMore = false;
for (index = 0; index < myForm.elements.length; ++index) {
field = myForm.elements[index];
if (field.type === "text" && field.style.display === "none") {
if (!foundOne) {
// Found one, show it
field.style.display = "";
foundOne = true;
}
else {
// Found more, so we don't need to hide the button
foundMore = true;
break;
}
}
}
if (!foundMore) {
// No more hidden fields, hide the button
this.style.display = "none";
}
};
Live example
If you want to add more text boxes to a form at runtime when they aren't in the markup, you can easily do that:
var textBox = document.createElement('input');
textBox.type = "text";
textBox.name = "somename";
formElement.appendChild(textBox);
Live example
Usually the structure will be a bit more complex than that, but that's the general idea.
Off-topic: A lot of these things can be made dramatically easier by leveraging a JavaScript library like jQuery, Prototype, YUI, Closure, or any of several others. They'll smooth over browser differences and provide a lot of value-add functionality, so you can focus on what you're actually trying to do rather than browser quirks and such.

Categories

Resources