How do I add JavaScript code on a webpage? - javascript

Could someone please tell me how to get this code working on a webpage? Particularly what should go in the header?
http://jsfiddle.net/mekwall/TJcP4/1/
Sorry if this is a basic question...steep learning curve!
Thanks

Your code is using the jQuery JavaScript library ... so your head will need to contain :
<script type="text/javascript" src="<jquery url>"></script>
Replace the <jquery url> with a valid url to the jQuery library. I suggest you use the Google CDN for the url or alternatively download a copy and store it on your server -> http://docs.jquery.com/Downloading_jQuery#Download_jQuery
Then to ensure your code runs once the DOM is ready wrap all of your JavaScript within the following :
$(document).ready(function() {
// your code here
});
Docs for ready() here
If your going to be using jQuery more I suggest you start reading here http://docs.jquery.com/How_jQuery_Works and if you going to learn JavaScript, you can't go wrong with reading this too -> https://developer.mozilla.org/en/JavaScript/Guide

Copy the code below, save it with a .html extension (e.g. test.html) and then double click to open.
<html>
<head>
<title>Page Title here</title>
</head>
<body>
<select id="t_dermal_name">
<option value="t_default_dermal">-- Choose --</option>
<option value="1" rel="30">Between Eyebrows</option>
<option value="7" rel="30">Individual Line Softening</option>
<option value="2" rel="30">Lip Contouring</option>
</select>
<select id="t_wrinkle_name">
<option value="t_default_wrinkle">-- Choose --</option>
<option value="1" rel="30">Between Eyebrows</option>
<option value="7" rel="30">Individual Line Softening</option>
<option value="2" rel="30">Lip Contouring</option>
</select>
<span id="output"></span>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js"></script><!--You can use a local version of jquery-->
<script type="text/javascript">
$(document).ready(function(){
function onSelectChange(){
var total = 0,
dermal = $("#t_dermal_name").find('option:selected'),
wrinkle = $("#t_wrinkle_name").find('option:selected');
if(value = dermal.attr('rel')){
total += parseInt(value);
}
if(value = wrinkle.attr('rel')){
total += parseInt(value);
}
$("#output").html(total);
}
$("#t_dermal_name").change(onSelectChange);
$("#t_wrinkle_name").change(onSelectChange);
});
</script>
</body>

Related

JavaScript Unit Converter with 2 dropdown menus

I'm new to JavaScript. Trying to build, for practice, a simple unit converter kind of like the one that google uses for converting kilos to pounds, inches to meters, etc.
I'd like to have an input box for entering the number value.
After that, two lists in the HTML files so i can choose in first the unit i convert from; and on the second the unit i convert to.
Maybe is an obvious one but i have not been able to find an answer to this problem. I'll post the last code/approach i tried.
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title></title>
<script src="simpleweightconversortest.js"></script>
</head>
<body>
<form>
<!-- Select 1-->
<label>From:</label>
<select name="converts" id="Selection">
<option>Chose Option</option>
<option value="kilograms1">Kilograms</option>
<option value="grams1">Grams</option>
<option value="miligrams1">Miligrams</option>
</select>
<!-- Select 2-->
<label>To:</label>
<select name="converts2" id="Selection2">
<option>Chose Option</option>
<option value="kilograms2">Kilograms</option>
<option value="grams2">Grams</option>
<option value="miligrams2">Miligrams</option>
</select>
<!--INPUT-->
<br>
<br>
<br>Value
<input type="number" id="value" placeholder="Insert value">
<!--RESULT -->
<br>Conversion
<input type="text" id="convertedOuput">
<br>
<br>
<input type="Button" onclick="Conversion()"
value="convert">
</form>
</body>
</html>
var val = document.getElementById("value").value;
var convertedOuput =document.getElementById("convertedOuput");
var selectFrom = document.getElementById("Selection");
var selectTo = document.getElementById("Selection2");
var madeSelection_1 = selecFrom[selectFrom.selectedIndex].value;
var madeSelection_2 = selectTo[selectTo.selectedIndex].value;
function Conversion() {
if (madeSelection_1 == "kilograms1" && madeSelection_2 == "kilograms2") {
var result = val * 1;
document.getElementById('convertedOuput').innerHTML = result;
}
}
I'm not getting any output in my "conversion" input box.
What am i doing wrong ? (i'm sure almost everything) Please help.
document.getElementById('convertedOuput').value = result should display the result of your function.
You have a typo:
var madeSelection_1 = selecFrom[selectFrom.selectedIndex].value;
This should be selectFrom and not selecFrom.
Also, you need to set the value of the input field using convertedOuput.value = result instead of setting its innerHTML. (By the way, convertedOuput is also misspelled, should be convertedOutput, but it's consistent, so it should work anyway.)
And finally, you are checking the selected units outside of the conversion button click handler, so they won't be updated when the user changes the selections in the dropdown. Move the corresponding lines which set value, convertedOuput and madeSelection_1 and madeSelection_2 into the Conversion function. (Explanation: Right now, the code is run once upon page load, so the values loaded there will always be the an empty string coming from the Choose option option. Afterwards, this part is run every time the button is clicked, so the values will be up to date.)
It works now:
function Conversion() {
var val = document.getElementById("value").value;
var convertedOutput = document.getElementById("convertedOutput");
var selectFrom = document.getElementById("Selection");
var selectTo = document.getElementById("Selection2");
var madeSelection_1 = selectFrom[selectFrom.selectedIndex].value;
var madeSelection_2 = selectTo[selectTo.selectedIndex].value;
if (madeSelection_1 == "kilograms1" && madeSelection_2 == "kilograms2") {
var result = val * 1;
convertedOutput.value = result;
}
}
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<title></title>
<script src="simpleweightconversortest.js"></script>
</head>
<body>
<form>
<!-- Select 1-->
<label>From:</label>
<select name="converts" id="Selection">
<option>Chose Option</option>
<option value="kilograms1">Kilograms</option>
<option value="grams1">Grams</option>
<option value="miligrams1">Miligrams</option>
</select>
<!-- Select 2-->
<label>To:</label>
<select name="converts2" id="Selection2">
<option>Chose Option</option>
<option value="kilograms2">Kilograms</option>
<option value="grams2">Grams</option>
<option value="miligrams2">Miligrams</option>
</select>
<!--INPUT-->
<br>
<br>
<br>Value
<input type="number" id="value" placeholder="Insert value">
<!--RESULT -->
<br>Conversion
<input type="text" id="convertedOutput">
<br>
<br>
<input type="Button" onclick="Conversion()" value="convert">
</form>
</body>
</html>
Note that you would have found a hint to these things more easily if you had looked into your browser's devtools - there you'd have seen an error about selecFrom.
Try pressing F12 in your browser. :-)
Furthermore, in the devtools you can do many powerful things to debug and analyze your code, such as executing arbitrary code at runtime, inspect variables, single-step through your lines of code, etc.
I'd recommend you to watch the Google Chrome Devtools Crash Course video on YouTube to get started!

Preview Image with Values from Select with Javascript

in my script, I have a select-field:
<select name="src[jumpMenu]" id="jumpMenu" onchange="ChangeImage(this.value,'preview');">
<option value="A">AStyle</option>
<option value="B">BStyle</option>
<option value="C">CStyle</option>
</select>
and I got this Javascript below:
<script language="Javascript" type="text/javascript">
<!--
function ChangeImage(newimage,imageid) {
if(document.getElementById(imageid).src != newimage)
document.getElementById(imageid).src = newimage;
}
// -->
</script>
and here is my problem:
I can't change the values because of the dependence for the other files (which I won't change).
Do you know any solution how to switch "A" to "img/src/A_top.png" for example and get it working with this script?
Thanks.
document.getElementById(imageid).src = "img/src/"+newimage+"_top.png";

html form select tag

This is kinda annoying, but even though I have worked with html/css and tiny bit of jquery I haven't yet learned much about forms etc.
I have a problem and I cant google the answer, but im sure some of you hardcore devs can tell me this quick!?
I need to make a form that could look like this:
HTML;
<form class="slct-form">
<select>
<option value="choose">Choose</option>
<option value="100.000">100.000</option>
<option value="150.000">150.000</option>
<option value="200.000">200.000</option>
</select>
</form>
I need that when I choose one of the elements in my dropdown form it should go to another url... Is this not possible? AND preferable without jquery!
If you add an id to your select, you can access it via plain javascript like this:
var selectmenu = document.getElementById("selectMenu");
selectmenu.onchange = function() {
var selectedOption = this.options[this.selectedIndex];
if (selectedOption.value != "choose")
window.location.assign = "/page.php?selectvalue=" + selectedOption.value;
}
You could do something like this:
<html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Test</title>
<script type="text/javascript">
function donav(dd)
{
var navUrl = "";
switch(dd.selectedIndex)
{
case 1:
navUrl = "http://www.google.com/";
break;
case 2:
navUrl = "http://www.bing.com";
break;
}
document.location.href = navUrl;
}
</script>
</head>
<body>
<form class="slct-form">
<select onchange="donav(this)">
<option value="choose">Choose</option>
<option value="100.000">100.000</option>
<option value="150.000">150.000</option>
<option value="200.000">200.000</option>
</select>
</form>
</body>
</html>
If i understand you corretly you want to bring a value from one page to another?
You could use the $_GET['name'] with php for that.

Javascript: Out of scope?

Re-Edited:
I went over to W3schools and played around in there javascript editor window to see what was going on. Here is a shorter script.
<html>
<body>
<script type="text/javascript">
var eType = document.getElementById("Type")
</script>
<select class="field select addr" id="Type">
<option value="Type:L" selected="selected">Location</option>
<option value="Type:C">Corporate</option>
<option value="Type:R">Remittama</option>
<option value="Type:M">Mailing</option>
</select>
<script type="text/javascript">
document.write(eType);
</script>
</body>
</html>
I did what ThiefMaster suggested on how to get the element by not using the .text or .value but as you can see if you run this code I still get a null at this step of the process. From what I can see and many suggestions I am doing this correctly. I know I must be missing something. Can anyone see it?
You're trying to get the element before you've actually put it on the page. Fix the order, and don't use document.write.
<html>
<body>
<select class="field select addr" id="Type">
<option value="Type:L" selected="selected">Location</option>
<option value="Type:C">Corporate</option>
<option value="Type:R">Remittama</option>
<option value="Type:M">Mailing</option>
</select>
<script type="text/javascript">
var eType = document.getElementById("Type")
document.body.appendChild(document.createTextNode(eType));
</script>
</body>
</html>
Your second code block is almost correct; you need to use the select element itself instead of its (non-existent) value:
var elem = document.getElementById("Type");
var type = elem.options[elem.selectedIndex].value;
Demo: http://jsfiddle.net/ThiefMaster/nw3nN/
If you had jQuery available you could drastically reduce the amount of code necessary:
var type = $('#Type').val();

about moving items in selectbox

I am trying to moving the items in a select box by using buttons.. for this i used swapNode().
But it is working only in IE. in chrome not working how to make it to work in chrome
Here is my code
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Moving the options up and down in Multiple select box </title>
<script type="text/javascript">
function move(id)
{
if (id=='up')
{
var len= document.f1.selectbox1.options.length;
if (document.f1.selectbox1[0].selected)
{
alert("This is the first record");
return false;
}
var up_id=document.f1.selectbox1.selectedIndex;
document.f1.selectbox1[up_id].swapNode(document.f1.selectbox1[up_id-1]);
}
if (id=='down')
{
var len=document.f1.selectbox1.options.length;
if (document.f1.selectbox1[len-1].selected)
{
alert("This is last record");
return false;
}
var down_id=document.f1.selectbox1.selectedIndex;
document.f1.selectbox1[down_id].swapNode(document.f1.selectbox1[down_id+1]);
}
if (id=='top')
{
var len=document.f1.selectbox1.options.length;
if (document.f1.selectbox1[0].selected)
{
alert("This is the first record");
return false;
}
var top_id=document.f1.selectbox1.selectedIndex
for (var j=top_id;j>0 ;j-- )
{
document.f1.selectbox1[j].swapNode(document.f1.selectbox1[j-1]);
}
}
if (id=='bottom')
{
var len=document.f1.selectbox1.options.length;;
if(document.f1.selectbox1[len-1].selected)
{
alert("This is last record");
return false;
}
var bot_id=document.f1.selectbox1.selectedIndex
for (var k=bot_id; k<len-1;k++)
{
document.f1.selectbox1[k].swapNode(document.f1.selectbox1[k+1]);
}
}
}
</script>
</head>
<body>
<form name="f1">
<select multiple size="20" style="width:30%" name="selectbox1" id="select_box">
<option id="1">First item</option>
<option id="2">Second item</option>
<option id="3">Third item</option>
<option id="4">Fourth item</option>
<option id="4">Fifth item</option>
<option id="4">Sixth item</option>
<option id="4">Seventh item</option>
<option id="4">Eighth item</option>
<option id="4">Ninth item</option>
<option id="4">Tenth item</option>
</select><br>
<input type="button" value="Up" onClick="move('up')">
<input type="button" value="Down" onClick="move('down')">
<input type="button" value="Top" onClick="move('top')">
<input type="button" value="Bottom" onClick="move('bottom')">
</form>
</body>
</html>
swapNode() is a Microsoft DOM extension and so as a result will not be recognized by browsers other than IE.
I ran your example in FireFox and used FireBug (You should download this plugin and use it in situations like this if you don't already) and sure enough the console was throwing an error that swapNode() was "not a function".
If I were to advise you from here, I would suggest going to lookup a jQuery plugin or something of that sort that achieves this kind functionality. Libraries like jQuery tend to offer cross browser solutions to these sorts of javascript problems and best of all are more often then not open source (so you can have a peek at the code and rework your own implementation if you would like).
http://jquery.com/
Alternatively, you could simply provide the swapNode() function in your code so that other browsers could pick it up. If you plan to go this route, you should be able to find an implementation with a quick Google search. I have provided a link to one such implementation below (I have not reviewed or used this code, use only after reviewing). In my humble opinion however, it is best to avoid solutions that have browser dependency as they are not always future proof and can often result in unforeseen issues.
http://sundberg.it/2006/05/12/swapnode_in_firefox
Good Luck!

Categories