I have a simple question. I have this function:
function buildGallery(assets) {
var $target = $("#assets");
var containerWidth = $target.width();
var overallWidth = 0;
var items = "";
$.each(assets, function (i, asset) {
var percent = 300 / asset.Metadata.ImageHeight;
var width = percent * asset.Metadata.ImageWidth;
var item = "<img src=\"" + asset.ThumbNail + "\" />";
overallWidth += width;
items += item;
if (overallWidth >= containerWidth) {
var $items = $(items);
var padding = overallWidth - containerWidth;
var counter = $items.find("img").length;
var p = padding / counter;
$items.each(function (n, image) {
console.log(image);
var img = "<div style=\"float: left; width: " + p + "px; overflow: auto;\">" + image + "</div>";
$target.append(img);
});
overallWidth = 0; // reset
items = "";
}
});
$target.removeClass("ajax");
}
my problem is that when I try to add the div to my target it just shows [object HTMLDivElement] instead of actually showing the html.
I have seen this before, but whatever I try does not seem to work.
Can someone give me a hand please?
The problem is that you are trying to build the new div element with the image DOM element, rather than its HTML:
var img = "<div style=\"float: left; width: " + p + "px; overflow: auto;\">" + image + "</div>";
// this is a DOM object not a string ^
If you want to use the string form, you need to get the HTML string from the object:
var img = "<div style=\"float: left; width: " + p + "px; overflow: auto;\">" + image.innerHTML + "</div>";
Or you could create a jQuery object of the div and append the image element to it:
var img = $("<div style=\"float: left; width: " + p + "px; overflow: auto;\"></div>").append(image);
Though it might be easier to read if you wrap each of the images in a div in one step and then add all of them to the $target at once:
$items.wrap("<div style=\"float: left; width: " + p + "px; overflow: auto;\"></div>").appendTo($target);
I think that you might have another problem with your code: it looks like the if (overallWidth >= containerWidth) { statement should be outside of the $.each(assets, ...) loop. With it inside, you will be adding each element in the assets list to the DOM length - index times.
Related
Context
I've used the "Intersection Observer API" to build an infinite scroll image gallery. Basically this API allows me to load more items when a certain dummy DOM element enters the viewport.
Prototype
Currently the prototype is implemented for an “iPhone X” (375x812) mobile device only. See: http://urbexco-acceptance.droppages.com/min_rep_ex_working (use Chrome DevTools 'inspect' device toolbar to select the right resolution). The image gallery is generated based on 57 items in the "database". When scrolling down, first 15 elements are loaded, then 15 more elements are loaded, then another 15 elements are loaded into the DOM, then another 10 elements are loaded, and finally 2 elements are loaded. When there are still more than 15 items left to be loaded, they are added using the following logic:
function addItems(n){
// Append new items to .items-wrapper
var items = document.querySelector('.items-wrapper');
for (var i = 0; i < n; i++) {
var url = 'https://img01.ztat.net/article/spp-media-p1/09742e38c25b3e1d9716e02f8e76e87d/89fc0bda6a2c446a8e9e0d8adbc9a4fe.jpg';
width = 170.5;
height = 246;
var newDiv = document.createElement('div');
newDiv.classList.add('item');
items.appendChild(newDiv);
newDiv.innerHTML = "<img src=" + '"' + url + '"' + "width=" + '"' + width + '"' + "height=" + height + "/>";
}
}
Minimal Working Example (no mobile view possible)
https://jsfiddle.net/9jqgzymo/
Objective
Since image width and height are currently hardcoded, I am now trying to assign width and height dynamically based on the image url. I try to achieve this using the getMeta() function:
function addItems(n){
// Append new items to .items-wrapper
var items = document.querySelector('.items-wrapper');
for (var i = 0; i < n; i++) {
var url = 'https://img01.ztat.net/article/spp-media-p1/09742e38c25b3e1d9716e02f8e76e87d/89fc0bda6a2c446a8e9e0d8adbc9a4fe.jpg';
getMeta(url);
}
}
function getMeta(url){
var img = new Image();
img.onload = function(){
res = calculateAspectRatioFit(this.width, this.height, 170.5, 246)
var newDiv = document.createElement('div');
newDiv.classList.add('item');
var items = document.querySelector('.items-wrapper');
items.appendChild(newDiv);
newDiv.innerHTML = "<img src=" + '"' + url + '"' + "width=" + '"' + res.width + '"' + "height=" + res.height + "/>";
};
img.src = url;
}
function calculateAspectRatioFit(srcWidth, srcHeight, maxWidth, maxHeight) {
var ratio = Math.min(maxWidth / srcWidth, maxHeight / srcHeight);
return { width: srcWidth*ratio, height: srcHeight*ratio };
}
Challenge
When implementing it this way, I see that - on initiation - already 30 items from the "database" where added to the DOM. Sometimes even all of them? Currently the non-working prototype is implemented for an “iPhone X” (375x812) mobile device only. See: http://urbexco-acceptance.droppages.com/min_rep_ex_not_working (use Chrome DevTools 'inspect' device toolbar to select the right resolution). For a minimal working example, see: https://jsfiddle.net/k3p20qno/
Key question
What is the reason that with my new implementation, on initiation, already 30 or more items are added to the DOM? How can I fix it?
Well the problem lies in here :
function getMeta(url){
var img = new Image();
img.onload = function(){
res = calculateAspectRatioFit(this.width, this.height, 170.5, 246)
var newDiv = document.createElement('div');
newDiv.classList.add('item');
var items = document.querySelector('.items-wrapper');
items.appendChild(newDiv);
newDiv.innerHTML = "<img src=" + '"' + url + '"' + "width=" + '"' + res.width + '"' + "height=" + res.height + "/>";
};
img.src = url;
}
Above code does an async operation with onload event. So it doesn't wait to image to be loaded.
If you turn this into a function that returns a promise you will get the result that you expect. And you should await where you call the function. That way when you add the intersection element it will add it as the last element of the items wrapper. If you don't await it will be added as the first element because the loading of the images will be async and will happen later.
function getMeta(url){
var img = new Image();
const p = new Promise(resolve =>{
img.onload = function(){
console.log( this.width+' '+ this.height );
res = calculateAspectRatioFit(this.width, this.height, 170.5, 246)
var newDiv = document.createElement('div');
newDiv.classList.add('item');
var items = document.querySelector('.items-wrapper');
items.appendChild(newDiv);
newDiv.innerHTML = "<img src=" + '"' + url + '"' + "width=" + '"' + res.width + '"' + "height=" + res.height + "/>";
resolve()
};
})
img.src = url;
return p;
}
Fiddle
Edit: Put the resolve() in the right position which is inside the load function
I'm trying to edit a page on Knack that allows JS modifications in combination with CSS formatting. The change I made was to lock the header on each page that uses an excel format. This seems to break when the user changes the number of rows in a drop down selection or navigates to the next page.
I'm sure there are a few ways to do this but I thought the easiest way to manage this would be to look at the first row's style and refresh the page if the minimum width is less than the desired length. Something like if the first entry in the header is not XXX amount of pixels, reload page using window.location.reload(); or similar.
Here is an example of the JS:
$( document ).on ('knack-page-render.any', (function(event, view, data) {
var $table = $('#view_60 > table');
var $bodyCells = $table.find('tbody tr:first').children();
var newWidths = [];
var colWidth = $bodyCells.map(function(index, val) {
/* Debug message*/
//console.log("Index: " + index + ". Value=" + $(this).width());
return $(this).width();
}).get();
var $headerCells = $table.find('thead tr').children();
//Evaluate new max width
$table.find('thead tr').children().each(function(i){
var headerWidth = $(this).width();
var bodyRowWidth = colWidth[i];
var newWidth = headerWidth;
if (bodyRowWidth > newWidth){
newWidth = bodyRowWidth;
}
newWidth++;
$(this).css("min-width", newWidth + "px");
newWidths[i] = newWidth;
/* Debug message*/
// console.log("Cell: " + i + ", header width=", headerWidth + ", bodyRowWidth=" + bodyRowWidth + ", idealWidth=" + newWidth + " Classes: " + $(this).attr('class'));
});
// Set new widths everywhere
$table.find('tbody tr:first').children().each(function(i){
//console.log("Setting new width to " + newWidths[i]);
$(this).css("min-width", ( newWidths[i]) + "px");
});
}));
Here is the associated CSS:
#view_52 table {border-collapse: collapse;}
#view_52 thead {display:block; padding: 2px; margin: 0px;}
#view_52 tbody {display:block; overflow:auto; width 100%; margin: 0px; height:500px; padding:2px;}
Change 'knack-page-render.any' to 'knack-view-render.any'
I have created a page where a list of members is shown. I created a Javascript function which shows the details of a user in a panel with id divpreview with position:absolute and z-index:100 the popup/panel does but I am not able to show it right above the the member.
<div runat="server" id="divpreview" class="preview">
</div>
<script type="text/javascript" language="javascript">
function showdiv(id, m, pos) {
var arr = new Array(7);
arr = id.split("###");
var divhtml = "";
divhtml += "<table border='1' style='background-color:#1C5E55;color:white;absolute' cellpadding='3' cellspacing='0'><tr><td>Sponsor Id</td><td>" + arr[0] + "</td></tr>";
divhtml += "<tr><td>Total Left Point</td><td>" + arr[1] + "</td></tr>";
divhtml += "<tr><td>Total Right Point</td><td>" + arr[2] + "</td></tr>";
divhtml += "<tr><td>Total Left Investment</td><td>" + arr[3] + "</td></tr>";
divhtml += "<tr><td>Total Right Investment</td><td>" + arr[4] + "</td></tr>";
divhtml += "<tr><td>Self Point </td><td>" + arr[5] + "</td></tr>";
divhtml += "<tr><td>Expiry Date</td><td>" + arr[6] + "</td></tr>";
divhtml += "</table>";
document.getElementById("ctl00_ContentPlaceHolder1_divpreview").innerHTML = divhtml;
var left = m.clientX + 10;
if (pos == 1) {
left = m.clientX - 230;
}
else {
left = m.clientX + 10;
}
debugger;
document.getElementById("ctl00_ContentPlaceHolder1_divpreview").style.left = left.toString() + 'px';
document.getElementById("ctl00_ContentPlaceHolder1_divpreview").style.display = "block";
var top = 0;
top = document.documentElement.scrollTop + m.clientY - 50;
document.getElementById("ctl00_ContentPlaceHolder1_divpreview").style.top = top.toString() + 'px';
}
function hidediv() {
document.getElementById("ctl00_ContentPlaceHolder1_divpreview").style.display = "none";
}
function movediv(m, pos) {
var left = m.clientX + 05;
if (pos == 1) {
left = m.clientX - 200;
}
else {
left = m.clientX + 10;
}
document.getElementById("ctl00_ContentPlaceHolder1_divpreview").style.left = left.toString() + 'px';
var top = 0;
top = document.documentElement.scrollTop + m.clientY - 50;
document.getElementById("ctl00_ContentPlaceHolder1_divpreview").style.top = top.toString() + 'px';
}
</script>
I want the panel to appear near the stars. What should I do.
Use
position: relative;
to the parent div. Position absolute element will "stop" when finding the closest positioned relative or positioned absolute element.
use this style on divpreview
<div runat="server" id="divpreview" class="preview" style="position:absolute;z-index:999;">
</div>
position: absolute;
parent div Position 'absolute'.
I have generated multiple barcodes using this code:
function getCode() {
var multipleCodes = document.getElementById('codeArea').value;
var eachLine = multipleCodes.split('\n');
console.log("eachLine = " + eachLine);
for (var i = 0; i < eachLine.length; i++) {
console.log("Inside loop: " + eachLine[i]);
var div = document.createElement('iframe');
div.innerHTML = "";
div.setAttribute('id', 'iFrameID' + i);
document.body.appendChild(div);
document.getElementById('iFrameID' + i).src = 'barCodeGenerator/generateBarCode.php?q=' + eachLine[i];
}
and trying to print it by using this method:
function printDiv(divName) {
var strName = document.getElementById("codeArea").value;
var imageId = document.getElementsByClassName('decoded');
var imagObject = new Image();
imagObject = imageId;
var originalImage = '<img id="imageViewer" src="' + imageSrc + '" style="padding-top: 20px" alt="' + imageSrc + '" />';
popup = window.open('', 'popup', 'toolbar=no,menubar=no,width=700,height=650');
popup.document.open();
popup.document.write("<html><head></head><body onload='print()'>");
popup.document.write(originalImage);
popup.document.write("</body></html>");
window.close('popup');
popup.document.close();
setTimeout(function () { popup.close(); }, 8000);
}
which only print single image by merging all barcodes.
How can i print them separately as multiple images.
Any help will be appreciated.
The most part of this code is irrelevant to your question. Consider removing your logs, the parts about showing popup and hiding it for more clearance.
Seems imageSrc variable in your code contains the source of one image, so you need to change your code by sending the array of image sources and iterating over it:
var originalImage = '';
// assuming imageSrc is an array of image sources
for (var i=; i < imageSrc.length; i++) {
// note that I'm changing the id of the image a litle bit to ensure it will remain unique
originalImage += '<img id="imageViewer' + i + '" src="' + imageSrc[i] + '" style="padding-top: 20px" alt="' + imageSrc[i] + '" />';
}
then the rest of your code must work.
I want to make a small game, but I have some start up problems.
When I try to get the position of track or trackCont, it always returns x: 0, y: 0. Doesn't get right position moving the DIV with:
float: right;
display: block;
and even doesn't work using:
position: absolute;
left: 100px;
Here's the code I am using:
var Player = new Array();
var trackEntity;
function getPosition(elem){
xPos = 0;
yPos = 0;
while(elem){
xPos += (elem.offsetLeft + elem.clientLeft);
yPos += (elem.offsetTop + elem.clientTop);
elem = elem.offsetParent;
}
return {x: xPos, y: yPos};
}
window.onload = function(){
trackEntity = document.getElementById("trackCont");
for (i = 0; i < 4; i += 1){
Player[i] = new Object();
document.body.innerHTML += "<div id='p" + i + "' class='player'></div>";
Player[i].entity = document.getElementById("p" + i);
Player[i].entity.style.backgroundColor = "rgb("
+ Math.floor(Math.random() * 256) + ", "
+ Math.floor(Math.random() * 256) + ", "
+ Math.floor(Math.random() * 256) +
")";
Player[i].entity.style.left = (getPosition(trackEntity).x) + 20;
Player[i].entity.style.top = (getPosition(trackEntity).y) + 20;
}
}
http://jsfiddle.net/dh8uf6Lp/
You need to supply a unit to when assigning a value to css left.
Player[i].entity.style.left = (getPosition(trackEntity).x) + 20 +"px";
If you assign a value to a css dimension or position property it will not update when no unit is given.
It seems that when getPosition(trackEntity) is called it doesn't know where it is in the DOM. This is caused by
document.body.innerHTML += "<div id='p" + i + "' class='player'></div>";
This causes the browser to redraw all elements and trackEntity loses it reference.
Solution: do not insert html via innerHTML, but create the div and append it to the DOM.
Player[i].entity = document.createElement("div");
Player[i].entity.id = "p" + i;
//etc.
document.body.appendChild(Player[i].entity);
//Run position code.
http://jsfiddle.net/dh8uf6Lp/3/