Develop Reference

How to pass a variable in document.getElementById. As well as getting undefined when calling a value in an array

<iframe id="frmFile" src="Book1.txt" onload="generateInventory();" style="display: none;"></iframe>
<script>
function csvpls() {
var oFrame = document.getElementById("frmFile");
var strRawContents = oFrame.contentWindow.document.body.childNodes[0].innerHTML;
while (strRawContents.indexOf("\r") >= 0)
strRawContents = strRawContents.replace("\r", "");
var arrLines = strRawContents.split(",");
return arrLines
}
function generateInventory(a, b) {
var xx = csvpls()
var div = document.createElement("div");
div.style.width = "1000px";
div.style.height = "100px";
div.style.background = "red";
div.style.color = "white";
div.innerHTML = "Hello " + xx[a] + " yes!";
document.getElementById(b).appendChild(div);
}
</script>
<div id="Q1"></div>
<script>
generateInventory(20, Q1);</script>
</body>
I am trying to create edit multiple divs with the following code. I hope to call each function with parameters to create the divs and put content in them.
So I have some problems with the code above. First off, document.getElementById(str).appendChild(div); is not working the way I want it to. It works if I put the div id "Q1" instead of b. Just wondering, if I can pass a variable through it. Secondly, when I change the div to "Q1", the div is generated, but the content in there is "Hello undefined Yes". If I call the array with xx[20] instead of xx[a], I would get what I want which is "Hello content yes". Sorry, this probably seems like a nuisance, any help is appreciated.

How To Create And Assign And Onclick Element To Another Element Created In JS

So, I am trying to make an element and then assign an onclick to it through JS.
Here is my code so far:
HTML
<div id = "Programs" onclick = "Cpb()">Programs</div>
JS
function Cpb() {
document.getElementById("AllBody").innerHTML = "";
var rh = document.createElement("h2");
var rht = document.createTextNode("Recent Programs");
rh.id = "Recentt";
var rh1 = document.createElement("h4");
var rh1t = document.createTextNode("test");
rh1t.onclick = window.open('website');
rh1.appendChild(rh1t);
rh.appendChild(rht);
}
So does anybody know how I can do this?

This javascript worked for me:
let h4Node = document.createElement("H4");
h4Node.innerHTML = "4th Header";
h4Node.onclick = function (){
alert('Oi!');
};
document.getElementById("demo").appendChild(h4Node);
Html:
<div class="demo"></div>
It will put an h4 element with an onclick event listener inside the demo div.

I think you want addEventListener.
Example:
rh1t.addEventListener('click', myHandlerFunction);
function myHandlerFunction () {
// ...
}
You can continue using onclick as you have in your code. But you'll need to do as I've done above and assign a function reference to it. Like this:
rh1t.onclick = myHandlerFunction;
function myHandlerFunction () {
window.open('website');
}

Setting onclick function dynamically in Javascript not working

hello =) I am trying to create a heading tag with some text in it.
var d = document.createElement("h5");
d.innerHTML = "Dungeon";
and then assigning an onclick listener.
d.onclick = function(){myFunction()};
which doesn't seem to be working. I've also tried
d.onmousedown = function(){myFunction();};
and
d.onclick = "myFunction()";
and
d.addEventListener("mousedown", function(){myFunction});
and none of them seem to be working. I have thrown in a couple tracers around it, everything runs through fine without syntax errors but the actual element when appended to the document doesn't have the function tied to it at all. Would anyone happen to know why? Thanks in advance =)
Edit:
Here is a more detailed block of my code. Would this make any difference?
var x = document.createElement("ul");
var y = document.createElement("li");
x.appendChild(y);
var d = document.createElement("h5");
d.innerHTML = "Dungeon";
y.appendChild(d);
console.log(0);
d.onclick = function() { alert('test'); }
console.log(1);

elem.addEventListener("click", function, false);

How to dynamically create list of <a> tags using js

I am creating html page which needs to create a list of links dynamically on a click of button. I know how to create this list when number of links to be created is known before like this:
//For 4 tags:
var mydiv = document.getElementById("myDiv");
var aTag = document.createElement('a');
aTag.innerHTML = "link1 text";
aTag.setAttribute('onclick',"func()");
mydiv.appendChild(aTag);
var bTag = document.createElement('b');
bTag.innerHTML = "link2 text";
bTag.setAttribute('onclick',"func()");
mydiv.appendChild(bTag);
var cTag = document.createElement('c');
cTag.innerHTML = "link3 text";
cTag.setAttribute('onclick',"func()");
mydiv.appendChild(cTag);
var dTag = document.createElement('d');
dTag.setAttribute('onclick',"func()");
dTag.innerHTML = "link4 text";
mydiv.appendChild(dTag);
But the problem is that the count will be known at run time and also on function call i need to identify the id of link that invoked function.. Can anybody help?

I don't know weather you receive or not the HTML to be shown in the anchor, but anyway, this should do the work:
function createAnchor(id, somethingElse) {
var anchor = document.createElement('a');
anchor.innerHTML = "link" + id + " text";
anchor.setAttribute("onclick", "func()");
return anchor;
}
Then you call the function like this:
function main(num_anchors) {
var mydiv = document.getElementById("myDiv");
for (var i = 0; i < num_anchors; i += 1) {
mydiv.appendChild(createAnchor(i));
}
}
Of course this code can be improved, but this is just for show how can this be possible.

Yes it is possible to do this at runtime .
JQuery provides very useful dom manipulation . So you can traverse the dom , filter what you need ..
you can find a lot of useful functions here .
http://api.jquery.com/category/traversing/
It would look something like this.
$( document ).ready(function() {
$( "a" ).each(function( index ) {
// enter code here..
}
});
document.ready gets invoked once the DOM has loaded.

JavaScript windows.onload or referencing new elements?

I'm trying to create a lightbox and I'm having trouble.
I think the problem is either because I have 2 window.onloads or because I'm trying to reference a newly created DOM element. I added some comments in the code below that explain what I'm trying to do.
//open lightbox
window.onload = showLargeImage;
function showLargeImage() {
var enlargeButton = document.getElementById("thumb1"); // thumb1 is a thumbnail you click to get the lightbox
enlargeButton.onclick = handleClick;
}
function handleClick() {
var lightboxContainerId = document.getElementById("lightboxContainer");
lightboxContainerId.innerHTML = '<div class="lightbox"><a class="reduceButton" href="#" ><img id="imageButton" class="largeImage" src="2012/images/web/web1.jpg" width="500" height="500" alt="Web Thumb 1"></a></div>';
} // the inner HTML creates the lightbox.
//close lightbox
window.onload = reduceImage; // i'm pretty sure that this windo.onload is the problem... or, that I'm referencing "imageButton" which is new to the DOM
function reduceImage() {
var reduceButton = document.getElementById("imageButton"); // you're supposed to click the big image in the lightbox to get close it.
reduceButton.onclick = handleReduceClick;
}
function handleReduceClick() {
var shadeId = document.getElementById("lightboxContainer");
shadeId.innerHTML = "say what"; // closing the lightbox simply strips everything out of the lightboxContainer
alert("oh yeah");
}

Here are a few reasons why your code is not working:
showLargeImage and reduceImage are missing invocation parentheses in the places where they are being assigned to window.onload. Without parentheses, window.onload is being assigned a function, but that function is not getting called. You should, for instance, have window.onload = showLargeImage();
As you suspected, the second window.onload is overwriting the first.
reduceButton is (as you also suspected) being assigned before it exists, causing an error.
Here is one solution that may work for you.
HTML:
<!DOCTYPE html>
<html><head><title></title>
</head><body>
View
<div id="lightboxcontainer"></div>
</body></html>
JavaScript:
window.onload = function() {
// click link to show
var enlargeButton = document.getElementById('thumb');
enlargeButton.onclick = function() {
var lightboxContainerId = document.getElementById('lightboxcontainer');
lightboxContainerId.innerHTML = '<img src="http://placehold.it/350x150"' +
'width="350" height="150 alt="Thumb 1">' +
'<p>Click image to hide.</p>';
};
// click image to hide
var reduceButton = document.getElementById('lightboxcontainer');
reduceButton.onclick = function() {
reduceButton.innerHTML = ''; // removes lightbox contents
};
};
Live demo: http://jsfiddle.net/ericmathison/BxwYY/7/

If the code is placed at the end of the <body> (or anywhere after your lightbox elements), just use this:
document.getElementById("thumb1").onclick = function () {
document.getElementById("lightboxContainer").innerHTML = '<div class="lightbox"><a class="reduceButton" href="#" ><img id="imageButton" class="largeImage" src="2012/images/web/web1.jpg" width="500" height="500" alt="Web Thumb 1"></a></div>';
document.getElementById("imageButton").onclick = function () {
document.getElementById("lightboxContainer").innerHTML = "say what";
alert("oh yeah");
};
}
This will do everything you want.