I am trying to learn how to use localStorage.
Partly imitating, I have written html that generates a page with a few tiles that you can drag and drop around the page.
For example
<script type="text/javascript">
function drag_start(event){
var style = window.getComputedStyle(event.target, null);
var str = (parseInt(style.getPropertyValue("left")) - event.clientX) + ',' + (parseInt(style.getPropertyValue("top")) - event.clientY)+ ',' + event.target.id;
event.dataTransfer.setData("Text",str);
event.stopPropagation();
}
function drop(event){
var offset = event.dataTransfer.getData("Text").split(',');
var dm = document.getElementById(offset[2]);
dm.style.left = (event.clientX + parseInt(offset[0],10)) + 'px';
dm.style.top = (event.clientY + parseInt(offset[1],10)) + 'px';
localStorage.setItem(dm.id,dm.style.left);
event.preventDefault();
return false;
}
function drag_over(event){
event.preventDefault();
return false;
}
</script>
I think that with a line like the one above beginning with "localStorage" I can save in localStorage the position after the drop. [The current line is just a mock example. Later, when I understand these things, I will actually store the position, or the offset.]
The part that I am confused is about how to retrieve the position from localStorage when the page is being loaded.
Say, that I am going to have one of the tiles being
<div id="tile3" draggable="true" ondragstart="drag_start(event)">
<a href="http://www.link.somewhere">
Link
</a>
</div>
I can say that the tile has style="position:absolute" and then I would need to retrieve the offset from localStorage and set as a property of the div.
But how to do this last part?
for the saving you use this javascript command:
(assuming thePosition is an array with two values (x and y position))
localStorage.setItem("position", JSON.Stringify(thePosition));
on the pageload you can do something like this (assuming you use jquery):
$(document).ready(function(){
var position = JSON.parse(localStorage.getItem("position"));
$('#the-divs-id').css({'left': position[0], 'top': position[1]});
});
edit: added JSON stringify/parse for the array
If you want to use no jquery:
window.onload = setDiv();
function setDiv(){
var position = JSON.parse(localStorage.getItem("position"));
document.getElementById(the-divs-id).style.left = position[0];
document.getElementById(the-divs-id).style.top = position[1];
}
edit: the looping question:
$(document).ready(function(){
// loops trough all divs with the-class
$('.the-class').each(function(){
// get the id from the current div
// and get the corresponding position from local storage
var id = $(this).attr('id'),
position = JSON.parse(localStorage.getItem(id));
// sets the css values for the current div
$(this).css({'left': position[0], 'top': position[1]});
});
});
Related
I am trying to convert an older jquery script to vanilla JS.
I have been working through most of them just one by one but am having a problem with the ajax call. Can anyone look at my original file and new file and see what is missing?
I am struggling mostly with converting the initial function calls to vanilla js. If you look at the 2nd code drop there most of the 'jquery-isms' have been rewritten in vanilla js. However I am having trouble converting my $.merge and $.extend actions. Furthermore, converting the $.ajax call to a JS version.
I tried to work on it modularly task by task but still haven't gotten it completely polished.
Jquery
(function($){
$(document).ready(function() {
$.ajax({
url: "https://api.flickr.com/services/rest/?method=flickr.galleries.getPhotos&api_key=*PRIVATE*c&gallery_id=72157720949295872&per_page=10&format=json&nojsoncallback=1",
type: "GET",
success: function(data) {
console.log("api successfully called")
let path = data.photos.photo
//for each photo, I save the different individual ids into variables so that they can be easily plugged into a URL
for (let i = 0; i < path.length; i++) {
let obj = path[i];
let farm_id = data.photos.photo[i].farm
let server_id = data.photos.photo[i].server
let photo_id = data.photos.photo[i].id
let secret = data.photos.photo[i].secret
//the static address to photos on Flickr is accessed through this address: https://farm{farm-id}.staticflickr.com/{server-id}/{id}_{secret}.jpg
//this variable is the direct link to access photos on Flickr, minus the ".jpg" designation that will be added, according to whether we are trying to access the medium picture or the large picture
let pic_url = "https://farm" + farm_id + ".staticflickr.com/" + server_id + "/" + photo_id + "_" + secret;
//this is the variable that stores the medium jpeg URL
let pic_url_m = pic_url + "_m.jpg";
//this stores an image tag which will be populated with a medium jpeg URL
let pic_img = ('<img src=\'' + pic_url_m + '\' alt = \"pic\" />');
//this appends the var pic_img to the photo_list div as the function loops through
//$('.body').append('#frame');
$('#photo-list').append(pic_img);
//this appends the class "paginate" to each img tag that is formed, ensuring that the the divs get passed to a later function called customPaginate
// $('img').addClass("paginate")
$('#photo-list img').addClass("paginate");
}
//this passes all divs with the class "pagination" to the function customPaginate
$('.pagination').customPaginate({
itemsToPaginate: ".paginate"
});
//when img tags with the class paginate are clicked, the following function is called
$('.paginate').click(function() {
//this variable saves the "src" or URL of (this) which is any element with the class "paginate"
let src = $(this).attr('src');
//this variable takes the "src" variable, slices the last six characters, and replaces it with "_c.jpg", a large version of the image URL
let src_l = src.slice(0, -6) + "_c.jpg";
//gives the "frame img" element a new attribute, which is the large image URL
$('#frame img').attr('src', src_l);
//allows the the "frame img" element to fade into the screen
$('#frame img').fadeIn();
//allows the "overlay" element to fade onto the screen
$('#overlay').fadeIn();
//when the "overlay" element is clicked, both the "overlay" and "frame img" elements
$('#overlay').click(function() {
$(this).fadeOut();
$('#frame img').fadeOut();
//removes the "src" attribute from "frame img", allowing it to be populated by other image URLs next time an image is clicked
$('#frame img').removeAttr('src');
});
});
}
});
});
//this function generates the customPaginate function, which paginates the images 10 to a page
$.fn.customPaginate = function(options)
{
let paginationContainer = this;
let defaults = {
//sets how many items to a page
itemsPerPage : 10
};
let settings = {};
//merges defaults and options into one one variable, settings
$.extend(settings, defaults, options);
//sets how many items will be on each page
let itemsPerPage = settings.itemsPerPage;
//sets which items are going to be
let itemsToPaginate = $(settings.itemsToPaginate);
//determines how many pages to generate based on the amount of items
let numberOfItems = Math.ceil((itemsToPaginate.length / itemsPerPage));
//this ul will contain the page numbers
$("<ul></ul>").prependTo(paginationContainer);
//loops through the ul tag the same number of times as there are pages. in this case, the loop will run 4 times
for(let index = 0; index < numberOfItems; index++)
{
paginationContainer.find('ul').append('<li>'+ (index+1) + '</li>');
}
//ensures that the current page only displays the items that should be on the specific page, and hides the others
itemsToPaginate.filter(":gt(" + (itemsPerPage - 1) + ")").hide();
//locates the first li element, adds activeClass element to it
paginationContainer.find("ul li").first().addClass(settings.activeClass).end().on('click', function(){
let $this = $(this);
//gives current page the activeClass setting
$this.addClass(settings.activeClass);
//takes activeClass setting away from non-current pages
$this.siblings().removeClass(settings.activeClass);
let pageNumber = $this.text();
//this variable designates that items located on the previous page times the number of items per page should be hidden
let itemsToHide = itemsToPaginate.filter(":lt(" + ((pageNumber-1) * itemsPerPage) + ")");
//this function merges itemsToHide and itemsToPaginate that are greater than the product of the pageNumber and the itemsPerPage minus 1, ensuring that these items are hidden from view
$.merge(itemsToHide, itemsToPaginate.filter(":gt(" + ((pageNumber * itemsPerPage) - 1) + ")"));
//designates these items as items that should be shown on the current page
let itemsToShow = itemsToPaginate.not(itemsToHide);
//hides items from other pages and shows items from current page
$("html,body").animate({scrollTop:"0px"}, function(){
itemsToHide.hide();
itemsToShow.show();
});
});
}
}(jQuery));
Vanilla JS (what im still stuck on)
(function($){
document.querySelector(document).ready(function() {
$.ajax({ //need to convert this to JS
url: "https://api.flickr.com/services/rest/?method=flickr.galleries.getPhotos&api_key=*PRIVATE*c&gallery_id=72157720949295872&per_page=10&format=json&nojsoncallback=1",
type: "GET",
success: function(data) {
console.log("api successfully called")
// ....truncated
}
});
});
$.fn.customPaginate = function()
{
let paginationContainer = this;
let defaults = {
itemsPerPage : 10
};
let settings = {};
//need to convert this extend to JS
$.extend(settings, defaults, options);
let itemsPerPage = settings.itemsPerPage;
// ....truncated
let pageNumber = qS.text();
let itemsToHide = itemsToPaginate.filter(":lt(" + ((pageNumber-1) * itemsPerPage) + ")");
//need to convert this extend to JS
$.merge(itemsToHide, itemsToPaginate.filter(":gt(" + ((pageNumber * itemsPerPage) - 1) + ")"));
});
}
}(jQuery));
First, please see: https://www.w3schools.com/js/js_ajax_intro.asp
Example you might consider.
function getPages(){
const xmlhttp = new XMLHttpRequest();
xmlhttp.onload = function() {
// Everything you want to do with the data
// this.responseText.photos.photo
}
xmlhttp.open("GET", "https://api.flickr.com/services/rest/?method=flickr.galleries.getPhotos&api_key=*PRIVATE*c&gallery_id=72157720949295872&per_page=10&format=json&nojsoncallback=1",);
xmlhttp.send();
}
I'm new to Javascript and I have a problem implementing PhotoSwipe plugin:
I'm trying to implement PhotoSwipe plugin for a web page using jQuery. Most of it is working correctly (opening a gallery, navigating slides). The problem happens when I close the gallery. The problem:
I click on image 1, this opens PhotoSwipe lightbox, I navigate to slide 2, and then close the gallery. This closes the gallery. But closing animation is played for image 1, while I am expecting it to be played for Image 2.
It works correctly on PhotoSwipe demo page, so it is an error in my code. If I copy/paste demo page Javascript code, it works correctly.
I believe I am missing some code that binds currently shown slide with respective thumbnail. My main issue with demo page is: I have a hard time understanding vanilla JS demo, what part is responsible for what action. Please help me find missing functionality.
Here's my code for PhotoSwipe "click to start gallery" event:
$('.my-gallery').each( function() {
var $pic = $(this);
var items = itemArray;
var $pswp = $('.pswp')[0];
$pic.on('click', 'figure', function(event) {
event.preventDefault();
var $index = $(this).index();
var options = {
index: $index,
getThumbBoundsFn: function(index) {
// get element we clicked on to determine its position in window
var thumbnail = event.target;
// get position of element relative to viewport
var rect = thumbnail.getBoundingClientRect();
// get window scroll Y
var pageYScroll = window.pageYOffset ||
document.documentElement.scrollTop;
return {x:rect.left, y:rect.top + pageYScroll, w:rect.width};
}
}
// Initialize PhotoSwipe
var lightBox = new PhotoSwipe($pswp, PhotoSwipeUI_Default, items, options);
lightBox.init();
});
});
My gallery (stripped down to 2 slides):
<div class="row my-gallery" itemscope itemtype="http://schema.org/ImageGallery" id="img-gallery">
<figure itemprop="associatedMedia" itemscope="" itemtype="http://schema.org/ImageObject">
<a href="images/nature/DSC_7216.jpg" itemprop="contentUrl" data-size="1200x795">
<img src="images/nature/DSC_7216_t.jpg" itemprop="thumbnail">
</a>
</figure>
<figure itemprop="associatedMedia" itemscope="" itemtype="http://schema.org/ImageObject">
<a href="images/nature/DSC_7218.jpg" itemprop="contentUrl" data-size="1200x795">
<img src="images/nature/DSC_7218_t.jpg" itemprop="thumbnail">
</a>
</figure>
</div>
Item array is generated from JSON:
[
{
"src": "images/nature/DSC_7216.jpg",
"msrc": "images/nature/DSC_7216_t.jpg",
"w":1200,
"h":795
},
{
"src": "images/nature/DSC_7218.jpg",
"msrc": "images/nature/DSC_7218_t.jpg",
"w":1200,
"h":795
}
]
JSON is hardcoded into a p element, is parsed using jQuery parser:
var itemArray = jQuery.parseJSON($(imageListSelector).html());
You can find the full page with problem on GitHub
PhotoSwipe demo on Codepen
Can you help me find what I am missing?
Edit:
I've tracked the issue down to this part of code in the original PhotoSwipe demo:
var thumbnail = items[index].el.getElementsByTagName('img')[0], // find thumbnail
If I replace this part with a fixed thumbnail selector (like I have in my jQuery - it contains "event target" reference), I can force PhotoSwipe demo to repeat my behavior - zoom out gets performed on same image. Not exactly the same thing that happens in my case, but close enough.
Now I just need to figure out how to change my getThumbBoundsFn to use actual thumbnail reference instead of event.target... I'll probably have to update my itemArray to include links to figure element, like the original PhotoSwipe demo. As I wrote earlier, I'm still new to Javascript, so figuring out some things takes time. Any help will be appreciated.
Figured it out myself. I really screwed things up by using event.target. The correct way of working with PhotoSwipe requires me to provide actual DOM element instead of a fixed one (like event target).
The correct way of doing this is just like demo:
save DOM element (selector) when creating itemArray
use DOM element from itemArray in order to provide correct element to calculate bounding rectangle.
Correct jQuery code:
var gallerySelector = "#img-gallery";
var imageListSelector = "#imageList";
// parse server reply (JSON, imitated, saved into a tag)
var itemArray = jQuery.parseJSON($(imageListSelector).html());
var index = 1;
// HTML structure of gallery image
var imageHTML = "<figure class=\"col-xs-12 col-sm-6 col-md-4\" " +
"itemprop=\"associatedMedia\" itemscope " +
"itemtype=\"http://schema.org/ImageObject\">\n" +
"<a href=\"{imageSource}\" itemprop=\"contentUrl\" data-size=\"{imageSize}\">\n" +
"<img class=\"img-responsive\" src=\"{imageThumb}\" itemprop=\"thumbnail\" />\n" +
"</a>\n</figure>";
// generate images based on JSON request (imitated) and appended them to the page
itemArray.forEach(function(item) {
var imageTags = imageHTML.replace("{imageSource}", item.src);
var imageTags = imageTags.replace("{imageSize}", (""+item.w+"x"+item.h));
var imageTags = imageTags.replace("{imageThumb}", item.msrc);
$(gallerySelector).append(imageTags);
item.el = $(gallerySelector + " figure:last img")[0];
});
$('.my-gallery').each( function() {
var $pic = $(this);
var $pswp = $('.pswp')[0];
$pic.on('click', 'figure', function(event) {
event.preventDefault();
var $index = $(this).index();
var options = {
index: $index,
getThumbBoundsFn: function(index) {
// get element we clicked on to determine its position in window
//var thumbnail = event.target;
var thumbnail = itemArray[index].el;
// get position of element relative to viewport
var rect = thumbnail.getBoundingClientRect();
// get window scroll Y
var pageYScroll = window.pageYOffset ||
document.documentElement.scrollTop;
return {x:rect.left, y:rect.top + pageYScroll, w:rect.width};
}
}
// Initialize PhotoSwipe
var lightBox = new PhotoSwipe($pswp, PhotoSwipeUI_Default, itemArray, options);
lightBox.init();
});
});
Summary of changes:
added item.el property, which saves last added element when it is appended to the gallery (in my case - figure img, since I need the img object to calculate its bounding rectangle).
Replaced event.target with respective itemArray[index].el (previously saved node).
Hope this helps! It took me a couple of hours and some trial and error with PhotoSwipe demo page to figure this out.
I'am trying to identify with javascript if I need to force a page break in my document.
One element that is overflow hidden. I loop through each of the elements within this document. I remove all last childs until the height of the element within the overflow:hidden element is smaller. Now I know, when to page break and I push all removed childs in the new page.
Works fine in browser. But not in PDF...
I'am using http://wkhtmltopdf.org/
See problem here: Left: PDF, Right: Browser (Chrome)
Height of 3262px vs 358px...
Same if I use .clientHeight or jQuery .height().
Does anyone know a workaround to get heights the same?
Some code:
function isOverflowed(element){
// return element.scrollHeight > element.clientHeight;
// console.log(element.clientHeight);
// console.log(element.parent().height() +'>'+ element.height());
return element.parent().height() < element.height();
}
// var daysWrapper = document.getElementById('days');
// var days = daysWrapper.querySelectorAll(".section.day");
var days = $('#days .section.day');
// console.log(days);
days.each(function() {
var $this = $(this);
var area = $this.find('.day-info');
var content = area.children();
var lasts = $( '<div class="lasts">' );
var test = 0;
while(isOverflowed(content)) {
var last = content.children().last();
// lasts.append( $( last ) );
last.clone().prependTo(lasts);
last.remove();
test++;
if (test > 6) break;
}
content.find('h1').html(area.height() + ' - ' + content.height());
if (lasts.children().length ) {
var newPage = $this.clone();
newPage.insertAfter($this);
newPage.find('.day-image').remove();
newPage.find('.day-info').removeClass('overflow');
newPage.find('.day-info').children().html(lasts.html());
}
});
Thanks!
I have a series of four elements. The first of which (#pro1) will appear on scrolling to a particular point on the page (this currently works), and the following three will trigger to appear one after another, with a small changeable interval in between each.
Any help would be greatly appreciated! A huge thank you in advance!
Here is the code for the first element, just needing to make the others appear after this one appears (#pro2, #pro3, #pro4, etc)
<script>
$(window).one("scroll", function() {
$('#pro1').each(function () {
var topOfWindow = $(window).scrollTop(),
bottomOfWindow = topOfWindow + $(window).height();
var imagePos = $(this).offset().top;
if(imagePos < bottomOfWindow-200 && imagePos >= topOfWindow-500){
$(this).addClass('bigEntrance2');
}else{
$(this).removeClass('bigEntrance2');
}
});
});
</script>
The key is using setInterval to call repeatedly the function that will create (or show if they are already created) the next elements.
It is important to not forget to clear the interval when the job is done.
Without the html and the css is difficult to realise exactly what you want to achieve, but from the next example you shouldn't have problems to update yours.
var interval = null;
var elementId = 1;
var numElements = 4;
var delay = 1000; //ms
$(document).ready(function()
{
//your first "pro1" element show up
var element = "<div>Im the pro" + elementId + " element!</div>";
$('body').append(element);
//in that moment we set the interval
interval = setInterval(show_next_element, delay);
});
function show_next_element()
{
//increment the counter elementId
elementId++;
//create the next element
var element = "<div>Im the pro" + elementId + " element!</div>";
//add it to the DOM
$('body').append(element);
//when our last element is created we clear the interval
if(elementId >= numElements)
clearInterval(interval);
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Hope it helps!
Lets say I have these images gallery, how do i randomly display the images everytime when i reload the page?
http://creativepreviews.com/fiddle/study/20131007/
Let's say the image will display in the background of the DIV, then the following should do it.
// JS
var imgArray = ["img1.jpg", "cat.jpg", "sky.jpg"]
function randomBg() {
x = Math.random()
y = Math.round(x * 10)
if (imgArray[y] != undefined) {
document.getElementById("blah").style.backgroundImage = "url('" + imgArray[y] + "')"
} else {
document.getElementById("blah").style.backgroundImage = "url('default.jpg')"
}
}
...and the HTML.
<script src="test.js"></script>
<body onload="randomBg()">
<div id="blah"></div>
...or you could replace the style.backgroundImage in the JS with innerHTML = <img src=" etc...
You could do something along these lines (not tested)
var grd = $('#grid');
var imgs = grd.children();
imgs.sort(function(){return (Math.round(Math.random()) - 0.5);});
grd.remove('li');
for(var i=0;i < imgs.length;i++) grd.append(imgs[i]);
In essence what we are doing is getting all the li elements in 'grid' into an array, randomizing them, removing them all from 'grid' and then putting them back in again.
If you had supplied a working fiddle rather than a link to the finished article it would be easier to modify it and provide a more complete solution.