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
Related
I am building a small web-tool where editors can write content by using buttons to add paragraphs and images. I store the elements with an id ((number of element) starting at 0 and incremented for every new element) and load with a button in order to a div "preview" where the content is supposed to be displayed as in the web page later on.
My issue is that, for a reason I don't understand, the image is always displayed below all the paragraphs instead of being in order. Presumably there is an easy fix, but I am very new to HTML, CSS and JS and couldn't find the solution online.
Sorry if this is a stupid mistake or the solution was already posted somewhere.
Javascript handling the preview rendering:
// Preview current document status
document.getElementById("previewButton").addEventListener("click", function() {
// Clear
document.getElementById("preview").innerHTML = "";
// Add all elements properly
var section = document.getElementById("preview");
var id = "preview";
for (var counter = 0; counter < element_counter; counter++) {
var type = document.getElementById(counter).nodeName;
// If text element
if (type === "TEXTAREA") {
var paragraph = document.createElement("p");
var text = document.getElementById(counter).value;
paragraph.setAttribute("id", id + counter);
paragraph.setAttribute("class", "flow-text");
paragraph.append(text);
section.appendChild(paragraph);
}
// If image element
if (type === "INPUT") {
var file = document.getElementById(counter).files[0];
var reader = new FileReader();
reader.onload = function(e) {
var image = document.createElement("img");
image.setAttribute("id", id + counter);
image.setAttribute("src", e.target.result);
image.setAttribute("class", "materialboxed responsive-img");
section.appendChild(image);
}
reader.readAsDataURL(file);
}
}
});
This might work. I can't test though without your code. However basically the principle at work is to isolate some of the vars so they represent distinct instantiations. And then immediately add the image element to the DOM. The reader.onload is expected to run asynchronously still.
enter code here if (type === "INPUT") {
(function() {
var file = document.getElementById(counter).files[0];
var reader = new FileReader();
var image = document.createElement("img");
image.setAttribute("id", id + counter);
image.setAttribute("class", "materialboxed responsive-img");
section.appendChild(image);
reader.onload = function(e) {
image.setAttribute("src", e.target.result);
}
reader.readAsDataURL(file);
}());
}
Have this issue here: I want to upload several images at once and show them directly afterwards in the browser. Everything is fine. However, doing this on mobile, sometimes I don't get all the images, but duplicates of another one from the file array. I have a suspicion, that this has to do with hardware limitations, since on PC everything works fine, but not on mobile.
Here is the fiddle. You can check it via mobile to see if duplicates appear.
So in result I get this on mobile. It wasn't two images in the selection, only one:
Here I have the Javascript snippet. Is there any room for improvement? Espacially onload processes are really confusing me from time to time. Is there any chance to write it better?
Javascript:
jQuery('.upload-mobile').change(function(){
jQuery('body').toggleClass( "loading" );
var imagecounter = jQuery(this)[0].files.length;
var loadcounter = 0;
for(var i = 0; i<imagecounter;i++){
for(var p = 1;p<=12;p++){
if(jQuery('#preview'+p).length<=0){
jQuery('.image-collection').prepend(jQuery('<div></div>',{id:'preview'+p,css:{'display':'inline-block'}}));
break;
};
}
var file = this.files[i];
var reader = new FileReader();
reader.onload = function(e){
for(var w = 1;w<=12;w++){
if(jQuery('#preview'+w).children().length>0) {
}
else{
var img = document.createElement("img");
img.src = e.target.result;
img.id = 'img'+w;
img.className += " img-responsive";
img.className += " border-blue";
img.className += " image-small";
img.className += " image-cover";
img.style.display='none';
document.getElementById("preview"+w).appendChild(img);
break;
}
}
loadcounter++;
if(loadcounter==imagecounter){
var count = jQuery('.image-collection').children().length;
jQuery('.image-small').delay('1500').fadeIn('3000', function(){
jQuery('#image-counter').text(count+'/12');
jQuery('body').removeClass( "loading" );
if( jQuery('#image-counter').text()=='12/12'){
jQuery('#upload-photos').fadeOut('200', function(){
jQuery('#three-cube-compact').fadeIn('200');
})
}
});
}
};
var image = reader.readAsDataURL(file);
}
});
EDIT:
I tried to use the forEach function. I didn't use the for each loops earlier, so I can not say much about the difference between foreach and for. I can't say if it works better or not, but I have seen less duplicates (maybe I didn't check to often to asume good functionality of it). It almost works, but maybe there is another way to make it work flawlessly?
Javascript:
jQuery('.upload-mobile').change(function(){
jQuery('body').toggleClass( "loading" );
var imagecounter = jQuery(this)[0].files.length;
var loadcounter = 0;
Array.from(this.files).forEach(function (image, index){
for(var p = 1;p<=12;p++){
if(jQuery('#preview'+p).length<=0){
jQuery('.image-collection').prepend(jQuery('<div></div>',{id:'preview'+p,css:{'display':'inline-block'}}));
break;
};
};
var reader = new FileReader();
reader.onload = function(e){
for(var w = 1;w<=12;w++){
if(jQuery('#preview'+w).children().length>0) {
}
else{
var img = document.createElement("img");
img.src = e.target.result;
img.id = 'img'+w;
img.className += " img-responsive";
img.className += " border-blue";
img.className += " image-small";
img.className += " image-cover";
img.style.display='none';
document.getElementById("preview"+w).appendChild(img);
break;
}
}
loadcounter++;
if(loadcounter==imagecounter){
var count = jQuery('.image-collection').children().length;
jQuery('.image-small').delay('1500').fadeIn('3000', function(){
jQuery('#image-counter').text(count+'/12');
jQuery('body').removeClass( "loading" );
if( jQuery('#image-counter').text()=='12/12'){
jQuery('#upload-photos').fadeOut('200', function(){
jQuery('#three-cube-compact').fadeIn('200');
})
}
});
}
};
var pic = reader.readAsDataURL(image);
});
});
EDIT2:
The fiddle was updated
EDIT3:
Added an image of the mobile screen. I also figured out it might has something to do with the file explorer on the mobile device. When I select using the first file explorer, I don't get the duplication bug:
However, by clicking on Browse ("Durchsuchen" on the image), I get to another file explorer. And using that one creates this "duplication bug":
Is there maybe a way to solve this or maybe to disable the Browse button?
I've looked at numerous other answers regarding this but haven't found a solution that has worked. I'm using a PHP page that contains some HTML code, with Javascript working some functions. Ideally I would select an image on the page, the image will become colored green as it is selected. I would then like to deselect the image and have it return to the original state. I can only get half-way there however. What am I missing? Is it something with post back?
Here's some code examples:
The HTML:<div onclick="changeImage(1)" id="toolDiv1"><img id="imgCh1" src="/images/Tooling/1.png"></div>
The Javascript function:
function changeImage(var i){
var img = document.getElementById("imgCh" + i + ".png");
if (img.src === "images/Tooling/" + i + ".png"){
img.src = "images/Tooling/" + i + "c.png";
}
else
{
img.src = "images/Tooling/" + i + ".png";
}
}`
The "1c.png" image is the one that is selected and should replace "1.png". There are multiple divs on this page that hold multiple images, which are named 2/2c, 3/3c, which is why the var i is included. Any insight? Thanks in advance.
You could do it something like this, it would also allow for different file names.
<img class="selectable" src="/images/Tooling/1.png"
data-original-source="/images/Tooling/1.png"
data-selected-source="/images/Tooling/1c.png">
<img class="selectable" src="/images/Tooling/2.png"
data-original-source="/images/Tooling/2.png"
data-selected-source="/images/Tooling/2c.png">
var images = document.getElementsByClassName('selectable');
for (var image of images) {
image.addEventListener('click', selectElementHandler);
}
function selectElementHandler(event) {
var image = event.target,
currentSrc = image.getAttribute('src'),
originalSrc = image.getAttribute('data-original-source'),
selectedSrc = image.getAttribute('data-selected-source'),
newSrc = currentSrc === originalSrc ? selectedSrc : originalSrc;
image.setAttribute('src', newSrc);
}
With comments:
// find all images with class "selectable"
var images = document.getElementsByClassName('selectable');
// add an event listener to each image that on click runs the "selectElementHandler" function
for (var image of images) {
image.addEventListener('click', selectElementHandler);
}
// the handler receives the event from the listener
function selectElementHandler(event) {
// the event contains lots of data, but we're only interested in which element was clicked (event.target)
var image = event.target,
currentSrc = image.getAttribute('src'),
originalSrc = image.getAttribute('data-original-source'),
selectedSrc = image.getAttribute('data-selected-source'),
// if the current src is the original one, set to selected
// if not we assume the current src is the selected one
// and we reset it to the original src
newSrc = currentSrc === originalSrc ? selectedSrc : originalSrc;
// actually set the new src for the image
image.setAttribute('src', newSrc);
}
Your problem is that javascript is returning the full path of the src (you can try alert(img.src); to verify this).
You could look up how to parse a file path to get the file name in javascript, if you want the most robust solution.
However, if you're sure that all your images will end in 'c.png', you could check for those last 5 characters, using a substring of the last 5 characters:
function changeImage(var i){
var img = document.getElementById("imgCh" + i);
if (img.src.substring(img.src.length - 5) === "c.png"){
img.src = "images/Tooling/" + i + ".png";
}
else
{
img.src = "images/Tooling/" + i + "c.png";
}
}
Good Evening Everyone.
Background: I am getting list of images from a Mongo Database and then I am calling ajax once to load those data in to particular div.
Here I am building those img tags dynamically and then appending it to a div.
Now I am trying to get the img id based on user operation, lets say clicks on 'share button' for a particular img, then I have to get the image id, and then have to look search the DB with that image id.
My code after the ajax call is:
function showImages(imageList) {
for ( var i = 0, len = imageList.length; i < len; i++) {
var elem = document.createElement("img");
elem.src = 'getImg/' + imageList[i][0] + '/' + imageList[i][1];
elem.id = imageList[i][2];
alert(elem.id);
elem.height = '100';
elem.width = '100';
elem.alt = 'SPF HYD';
/* $("a[id=shareImage]").click(function(){
var qwerty = $("img", $(this).parent()).attr("id");
alert('image id is after anchor by click...'+qwerty);
}); */
var image = document.getElementById("imageLoad");
image.appendChild(elem);
}
}
Could any one help me to get the image id onclick or any button trigger?
I threw a quick demo together to demonstrate what I meant. It's made possible using jQuery event Delagation
function showImages(imageList) {
for ( var i = 0, len = imageList.length; i < len; i++) {
var elem = document.createElement("img");
elem.src = 'getImg/' + imageList[i][0] + '/' + imageList[i][1];
elem.id = imageList[i][2];
console.log(elem.id);
elem.height = '100';
elem.width = '100';
elem.alt = 'SPF HYD';
var image = document.getElementById("imageLoad");
image.appendChild(elem);
}
}
//The event handler is registered on the document object - the second argument here is the delegate, <img>
$(document).on("click", "img", function(e) {
alert($(this).attr("id"));
});
var imageList = [[0, 1, 2], [3, 4, 5]]; //These values are merely for testing
showImages(imageList);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="imageLoad"></div>
Using Event Delegation is necessary here because your img tags are being dynamically generated, plus it's a lot cleaner to register one event handler for all img tags, rather than an event handler for each
Hope this helps
Use addEventListener function to add an Event Listener to your dynamically created element.
var div = document.getElementById("div");
var imgShare = document.createElement("img");
imgShare.src = "http://icons.iconarchive.com/icons/graphicloads/100-flat-2/128/share-2-icon.png";
imgShare.id = "post002";
imgShare.addEventListener("click", share);
div.appendChild(imgShare);
var imgLike = document.createElement("img");
imgLike.src = "http://www.brandsoftheworld.com/sites/default/files/styles/logo-thumbnail/public/102011/like_icon.png?itok=nkurUMlZ";
imgLike.id = "post001";
imgLike.addEventListener("click", like);
div.appendChild(imgLike);
function share(e){
alert("Share id:" + e.currentTarget.id);
}
function like(e){
alert("like id:" + e.currentTarget.id);
}
<div id="div"></div>
JSFiddle Link...
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);