Dynamic img creation through a link without attaching multiple instances - javascript

I have a link that is attached with an "onclick" function. When pressed it attaches an img element into a separate div called "mediaBox". The problem I'm having is that if it's pressed multiple times then it attaches more instances of the img. How can I control this. I'm still new to JavaScript and I prefer to receive this answer in pure Javascript not jQuery, as I will cross that bridge after I have a full understanding of Javascript.
var rkf = document.getElementById("submenulinks").getElementsByTagName("li")[0];
rkf.onclick = function(){
var client = document.getElementById('client');
var description2 = document.getElementById('description2');
var role = document.getElementById('role');
var mediaBox = document.getElementById('mediaBox');
var thumb = document.getElementById("thumb");
var client2 = document.getElementById("client2");
var newImage = document.createElement("img");
client2.innerHTML = "Role - Applications";
client.innerHTML = "RKF Real Estate";
client2.innerHTML = "Role - Applications";
description2.innerHTML = "Quarterly Catalog of Exclusive Listings managed by RKF";
role.innerHTML = "Custom designed Cover and listings content. Tables were also utilized within Indesign. <br><br><b><i> Photoshop and Indesign</i></b>";
newImage.setAttribute("src", "../images/rkf_cover.jpg");
newImage.setAttribute("height", "500px");
newImage.setAttribute("width", "387px");
newImage.setAttribute("alt", "rkf");
newImage.setAttribute("href", "#");
mediaBox.style.backgroundImage = "none";
document.getElementById("mediaBox").appendChild(newImage);
newImage.style.display = "block";
newImage.style.marginLeft = "auto";
newImage.style.marginRight = "auto";
newImage.style.marginTop = "25px";
}

rkf.onclick = function(){
var client = document.getElementById('client');
...
...
...
// Remove the handler after it ran once.
this.onclick = null; // <<<<<========================
}
Since you do want to use jQuery in the future, it's equal to:
$('#submenulinks li:first').one('click', handler);

Related

Javascript functions do not work after updating content (Using Document Ready atm.)

I have a question I am working with a form based shopping cart add function and a livesearch (PHP) function where it requests new data with the same classes. I have seen multiple examples besides (document.ready) but none of them seemed to work correctly after the DOM Content has been modified by the PHP livesearch function. (The current method is on the document ready function as you guys can see.
Thanks in advance!
// Icon Click Focus
$('.product').on('click', function() {
var strId = '';
var strId = $(this).attr('class');
var strId2 = strId.replace(' product','');
var strId3 = strId2.replace('product-','');
var formData = "product"+strId3;
document.getElementById("product_toevoeg_id").value = strId3;
var productNaam = $("#"+formData+" .f-productnaam").val();
document.getElementById("productnaam").innerHTML = productNaam;
document.getElementById("product_naam_form").value = productNaam;
var productIngredienten = $("#"+formData+" .f-ingredienten").val();
document.getElementById("ingredienten").innerHTML = productIngredienten;
document.getElementById("ingredienten_form").value = productIngredienten;

JavaScript, move an image on another

I want to move an image on another one. I saw on forum, the best way to do this is to use destination.appendChild(elementToMove). But when I use it, my elementToMove just disappears.
Here is a fiddle for what I want to do (but that's not working):
JS Fiddle
Here is my JS Code:
var body = document.getElementsByTagName("body")[0];
var td_sign = document.getElementById("sign");
var td_moon = document.getElementById("moon");
var sign = document.createElement("img");
sign.src="http://img11.hostingpics.net/thumbs/mini_723286sign.png";
var moon = document.createElement("img");
moon.src="http://img11.hostingpics.net/thumbs/mini_418048moon.png";
td_sign.appendChild(sign);
td_moon.appendChild(moon);
var testbutton = document.createElement('input');
testbutton.type='button';
testbutton.value='test';
testbutton.onclick = function(){
sign.appendChild(moon);
}
body.appendChild(testbutton);
I just want to use JavaScript.

How to append multiple elements to a div using DocumentFragment

function JGallery() {
this.elements = this._init();
this.overlay = this.elements.overlay;
this.media_hld = this.elements.media_hld;
}
JGallery.prototype._init = function(){
var overlay = document.createElement('div');
var media_hld = document.createElement('div');
return{
'overlay': overlay,
'media_hld': media_hld
}
};
This is where I create a document fragment and using it so I can add several div to same element:
JGallery.prototype.getReference = function(holder) {
var overlay = this.overlay;
var media_hld = this.media_hld;
var that = this;
var holderChildren = holder.querySelectorAll('img');
var docfrag = document.createDocumentFragment();
holderChildren.forEach(function (e) {
e.addEventListener('click', JGallery.prototype.showMe.bind(that), false);
var media_holder = that.media_hld;
media_holder.textContent = "<img src="+e.getAttribute('src')+">";
docfrag.appendChild(media_holder);
//it only appends the last child of my array...
});
overlay.appendChild(docfrag);
};
my goal is to have something like this:
<div class="JGallery_BG">
<div class="JGallery_mediaContainer"><img src="images/thumb_video.jpg"></div>
<div class="JGallery_mediaContainer"><img src="images/thumb_video.jpg"></div>
</div>
by the way the forEach function works well, 8 or 9 times. But I'm not sure whether it adds node to docFrag on every run or not.
Another thing, I'm not insisting to use a document fragment, if there is a better way to add multiple elements to one element, I like to know about it and use it.
One of the problems is that you are constantly re-using the same media holder <div> element in every iterations.
In the code below that.media_hld is always referencing the same element.
var media_holder = that.media_hld;
media_holder.textContent = "<img src="+e.getAttribute('src')+">";
docfrag.appendChild(media_holder);
If you clone the node it should work and you also need to set the innerHTML property, not the textContent.
var media_holder = that.media_hld.cloneNode();
One other thing I did spot is that what's returned from querySelectorAll is not an array and thus doesn't have a forEach method.
You could borrow forEach from an array instance though:
[].forEach.call(holderChildren, forEachBodyFunction);
The entire thing could read:
JGallery.prototype.getReference = function(holder) {
var docfrag = document.createDocumentFragment(),
images = holder.querySelectorAll('img');
[].forEach.call(images, function (img) {
img.addEventListener('click', JGallery.prototype.showMe.bind(this), false);
var media_holder = this.media_hld.cloneNode();
media_holder.appendChild(img.cloneNode());
docfrag.appendChild(media_holder);
}.bind(this));
this.overlay.appendChild(docfrag);
};

Javascript: Get the innerHTML of a dynamically created div

I am retrieving some information from an xml file ( movie information ) and I am creating dynamically some DOM elements according to each movie. I want, when I click on the test element, to get the value of the title of the movie. Right now, no matter which movie I click, it gets the title of the last movie that was introduced.
How can I get the title of each individual movie when I click on that div and not the last one introduced by the for-loop?
xmlDoc=xmlhttp.responseXML;
var x=xmlDoc.getElementsByTagName("movie");
for (i=0;i<x.length;i++)
{
var titlu = x[i].getElementsByTagName("title")[0].childNodes[0].nodeValue;
var description = x[i].getElementsByTagName("description")[0].childNodes[0].nodeValue;
var descriere = document.createElement('div');
descriere.className='expandedDescriere';
descriere.innerHTML = description;
var titlediv = document.createElement('div');
titlediv.className = 'title';
titlediv.id='title';
titlediv.innerHTML = title;
var test=document.createElement('div');
test.className='test';
test.onclick= function(){
var filmName= test.previousSibling.innerHTML;
alert(filmName);
}
placeholder.appendChild(titlediv);
placeholder.appendChild(test);
placeholder.appendChild(descriere);
}
I think your problem might be in the function you assigned to onclick:
test.onclick= function(){
var filmName= test.previousSibling.innerHTML; // <===
alert(filmName);
}
the marked line should be var filmName= this.previousSibling.innerHTML;
My guess is that the var test is hoisted out of the for loop, meaning that when the loop finished, all the onclick function are referencing the same test variable which is the last element you created.
Use this to reference the clicked element:
test.onclick = function() {
var filmName = this.previousSibling.innerHTML;
alert(filmName);
};

Smilie system: Event to add image in textarea fails

I'm trying to create a personalized smilies system to train my JavaScript.
To accomplish that I have an offline system to save the various user smilies (I only save the urls).
After obtaining the data I try to make them appear above the textarea I want. So far so good!
Now, the problem comes when it's time to add the events to the images.
I try to add event listeners to each image but no matter which image I press only the last image event is triggered.
This is: all images appear side by side correctly but what is inserted in the textarea is the last image that is iterated in the cycle.
Meaningful code:
/* Insert the code in the right place in the textarea*/
function putInTxtarea(text, textarea) {
// Mozilla text range replace.
if (typeof(textarea.selectionStart) != "undefined") {
var begin = textarea.value.substr(0, textarea.selectionStart);
var end = textarea.value.substr(textarea.selectionEnd);
var scrollPos = textarea.scrollTop;
textarea.value = begin + text + end;
if (textarea.setSelectionRange)
{
textarea.focus();
textarea.setSelectionRange(begin.length + text.length, begin.length + text.length);
}
textarea.scrollTop = scrollPos;
}
// Just put it on the end.
else {
textarea.value += text;
textarea.focus(textarea.value.length - 1);
}
var elem = document.createElement("div");
elem.id = "mySmilies";
elem.innerHTML = "";
for each (url in smiliesUrl){
var img = document.createElement("img");
img.src = url;
img.style.cursor = "pointer";
img.addEventListener('click',
function(){putInTxtarea('[img]'+url+'[/img]', document.getElementsByName('message')[0]);
};, false); // here is the event attaching
elem.appendChild(img);
}
Don't use for each...in. This is a construct only available in Firefox (at least it is non-standard).
You are making the typical creating-a-function-in-a-loop mistake. JavaScript has only function scope. Every function you create in the loop has references to the same variables (url in your case) and this variable will have the value of the last URL after the loop finished. You need to introduce a new scope:
function createClickHandler(url) {
var target = document.getElementsByName('message')[0];
return function() {
putInTxtarea('[img]'+url+'[/img]', target);
}
}
// assuming smiliesUrl is an array
for(var i = smiliesUrl.length;i--;) {
var url = smiliesUrl[i];
var img = document.createElement("img");
img.src = url;
img.style.cursor = "pointer";
img.addEventListener('click', createClickHandler(url), false);
elem.appendChild(img);
}
Another possible is to simply access the image from the event handler. It should available via this:
img.addEventListener('click', function(){
putInTxtarea('[img]'+this.src+'[/img]',
document.getElementsByName('message')[0]);
};, false);
This seams to be a closure issue. the variable url points to the url used in the loop, and at the time of execution it is always be the last url.
for(url in smiliesUrl){
var img = document.createElement("img");
img.src = url;
img.style.cursor = "pointer";
var func = function(jUrl){
return function(){
putInTxtarea('[img]' + jUrl + '[/img]',
document.getElementsByName('message')[0]);
};
}(url);
img.addEventListener('click', func, false);
}
For more on closures in javascript see This question

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