I can't get the actually LazyLoad plugin to work for me so I am trying to write my own with. Currently I have a list of images loading inside of a DIV. They are pulled by a PHP query to the mysql database. The DIV scroll is set to auto. The code I am using is:
<div id="b1" style="overflow:auto;">
<?PHP $result = mysql_query("SELECT * FROM images");
while($row = mysql_fetch_assoc($result)) {
echo "<img src='$row[photo]' style='display:none'> <br>";
}
</div>
<script type="text/javascript">
function imgCheck() {
var position = $("img").offset().top;
var scrollCheck = $("#b1").scrollTop() + $("#b1").height();
if ( scrollCheck > position) {
$("img").fadeIn("fast");
}
$("#b1").scroll( function() { imgCheck() } );
</script>
Although this is not quite working for me. Could anyone help me out or shoot out some suggestions?
A couple of things:
As the others have already said, your code has syntax errors - both with the PHP and the Javascript.
If you use display: none, the elements will not take up any height, thus causing the entire thing to become unscrollable and fail.
The first few elements should be visible without the user having to start scrolling
Taking these into consideration, we can try writing this this way:
// Cache the containing element and it's height
var b1 = $('#b1'),
h = b1.height();
// Insert 20 img's - simulating server-side code
for(var i = 0; i < 20; i++){
$('<img />', {
src: 'http://placehold.it/100x100',
alt: '',
class: 'hidden',
width: 100,
height: 100
// visibility: hidden to retain it's size
}).css('visibility', 'hidden').appendTo(b1);
}
b1.scroll(function(){
// Loop through only hidden images
$('img.hidden').each(function(){
// $(this).position().top calculates the offset to the parent
// So scrolling is already taken care of here
if(h > $(this).position().top){
// Remove class, set visibility back to visible,
// then hide and fade in image
$(this).css('visibility', 'visible')
.hide()
.removeClass('hidden')
.fadeIn(300);
} else {
// No need to check the rest - everything below this image
// will always evaluate to false - so we exit out of the each loop
return false;
}
});
// Trigger once to show the first few images
}).trigger('scroll');
See a demo of this here: http://jsfiddle.net/yijiang/eXSXm/2
If all of the images are hidden, then there will never be a 'scroll' even called as the element will never scroll.
What exactly are you trying to achieve? If it is to have new images that weren't previously visible, but now may be, become visible then you will have to do something like;
<div id="b1" style="overflow:auto;">
<?php $result = mysql_query("SELECT * FROM images");
while($row = mysql_fetch_assoc($result)) {
echo "<img src='$row[photo]' style='visibility:hidden'> <br>";
} ?>
</div>
<script type="text/javascript">
function imgCheck() {
var scrollCheck = $("#b1").scrollTop() + $("#b1").height();
$("#b1 img").each(function() {
var position = $(this).offset().top;
if (scrollCheck > position) {
$(this).fadeIn("fast");
}
});
}
$(document).ready(imgCheck);
$("#b1").scroll(imgCheck);
</script>
Note that I haven't tested the above, and I can imagine that it will result in all images being shown immediately, since all of their 'top's will be 0 due to them all being hidden and not having their position effected by previous images in the DOM.
Edit
I've changed the code above so the img's have visibility:hidden, which should give them a height and take up space in the DOM
I've been testing it, it seems to work with some modifications:
http://jsfiddle.net/antiflu/zEHtu/
Some things I had to change:
I added the closing } for the imgCheck() function, you forgot it
Some items need to be visible from the beginning on, otherwise the scrollbar never appears and imgCheck() is never called.
OK the problem with the above was that the images don't fade in separately upon scroll. I got it to work though with some modifications:
http://jsfiddle.net/antiflu/GdzmQ/
What I changed:
I changed the display: none to opacity: 0 so that any invisible picture has at least an empty placeholder of the same size, so that the scroll bar will be visible.
I then fade in using animate to opacity: 1
I used jQuery each() to iterate over the images and check for each of them if they should or should not be faded in (instead of checking for all, like before).
I wrapped the images in DIV's. I don't think it's necessary, but it doesn't harm either.
I tagged each image with an id, so that I can single them out for the fadein.
There are still some esthetic issues but this should help you on your way.
Related
I'm making a hangman game using JavaScript and need to hide some HTML for a few seconds to display an error message, and then revert back to the original HTML. I've tried using setTimeout(); and setInterval(); but those seem to just wait a few seconds before displaying the error message.
Here's the code for reference:
<div class="row text-center">
<div id="alredGuess" class="col">
<div>
<span id="guessedLetters"></span> <br>
</div>
<div>Guesses left:<span id="guessesLeft">10</span></div>
<div>Wins:<span id="wins">0</span></div>
<div>Losses:<span id="losses">0</span></div>
</div>
</div>
JS:
if (gameRunning === true && guessedLetterBank.indexOf(letter) === -1) {
// run game logic
guessedLetterBank.push(letter);
// Check if letter is in picked word
for (var i = 0; i < pickedWord.length; i++) {
//convert to lower case
if (pickedWord[i].toLowerCase() === letter.toLowerCase()) {
//if match, swap placeholder
pickedWordPlaceholderArr[i] = pickedWord[i];
}
}
$placeholders.textContent = pickedWordPlaceholderArr.join("");
checkIncorrect(letter);
} else if (gameRunning === false) {
$placeholders.textContent = "Press \"A\" To Begin!"
} else {
//alert("You've already guessed this letter.")
function newAlert() {
var hideDiv = document.getElementById("alredGuess");
if (hideDiv.style.display = "block") {
hideDiv.style.display = "none";
}
}
hideDiv.textContent("You've already guessed this letter!");
function showDiv() {
var showDiv = document.getElementById("alredGuess");
if (hideDiv.style.display = "none") {
hideDiv.style.display = "block";
}
}
}
}
setInterval(newAlert, 3000);
}
Tip 1
Well, first of all i don't recommend using display: block|none to show or hide DOM elements. Instead try using visibility: visible|hidden or better, toggle a css class name such as : .hidden. That's because when you set a DOM element's display to none, its width and height are gonna be set to zero, often causing an unwanted loss of space because the DOM node visually collapses. With the visibility property, for example, the element just disappears without loss of space.
Tip 2
Error/status messages should always live within their own containers. Do not display messages in substitution of some content you need to revert back after.
It is always better to prepare an empty <div>, hide it by default with a generic .hiddenCSS class and then remove this one as soon as you need to display the container.
Suggested solution
Now, in your case, i think you're using setIntervalin the wrong way. You have to immediately show the alert message, then make it disappear after a few seconds.
As suggested above, this should be done by toggling CSS classes, using different containers and using setTimeout in order to remove/add the CSS classes as soon as the interval is over. Basically, the setTimeout restores everything to its original state.
So, given this HTML code:
<div id="alredGuess">This is the original text</div>
<div id="alertbox" class="hidden"></div>
and this CSS code:
.hidden { visibility: hidden; }
try this:
var alertTimeout = 1000; // Timeout in milliseconds.
function showAlertMessage() {
// This is your original text container.
var alredGuess = document.getElementById("alredGuess");
// This is the new error message container named #alertbox
var alertBox = document.getElementById("alertbox");
// Now let's fill it with the specific error text (better using HTML here).
alertBox.innerHTML = "You've already guessed this letter!";
// Hide the original container by adding an .hidden css class.
alredGuess.classList.add('hidden');
// Show the error message container by removing its default .hidden css class.
alertBox.classList.remove('hidden');
// Then set up an interval: as it ends, revert everything to its original state.
setTimeout(function() {
alertBox.classList.add('hidden');
alredGuess.classList.remove('hidden');
}, alertTimeout);
}
// Call the function.
showAlertMessage();
Fiddle: https://jsfiddle.net/qyk4jspd/
Hope this helps.
I'm appending some HTML to my button on a click, like this:
jQuery(document).ready(function($) {
$('#sprout-view-grant-access-button').on('click', function(e) {
$(this).toggleClass('request-help-cta-transition', 1000, 'easeOutSine');
var callback = $(e.currentTarget).attr('data-grant-access-callback');
var wrapper = $('.dynamic-container');
console.log(wrapper);
if( typeof window[callback] !== 'function') {
console.log('Callback not exist: %s', callback);
}
var already_exists = wrapper.find('.main-grant-access');
console.log(already_exists);
if( already_exists.length ) {
already_exists.remove();
}
var markup = $(window[callback](e.currentTarget));
wrapper.append(markup);
});
});
function generate_grant_access_container_markup() {
var contact_data_array = contact_data;
var template = jQuery('#template-sprout-grant-access-container')
return mustache(template.html(), {
test: 's'
});
}
As per the code, whatever comes from generate_grant_access_container_markup will be put inside dynamic-container and shown.
My problem is that, the newly added code just doesn't wanna dissapear upon clicking (toggle) of the button once again.
Here's my syntax / mustache template:
<script type="template/mustache" id="template-sprout-grant-access-container">
<p class="main-grant-access">{{{test}}}</p>
</script>
And here's the container:
<div class="button-nice request-help-cta" id="sprout-view-grant-access-button" data-grant-access-callback="generate_grant_access_container_markup">
Grant Devs Access
<div class="dynamic-container"></div>
</div>
I understand that the click event only knows about items that are in the DOM at the moment of the click, but how can I make it aware of everything that gets added after?
I would recommend visibility: hidden. Both display none and removing elements from the dom mess with the flow of the website. You can be sure you would not affect the design with visibility: hidden.
I don't deal with Jquery at all but it seems like this Stack overflow covers the method to set it up well.
Equivalent of jQuery .hide() to set visibility: hidden
Im creating a fixed header where on load, the logo is flat white. On scroll, it changes to the full color logo.
However, when scrolling back to the top, it stays the same colored logo instead of going back to white.
Here's the code (and a pen)
$(function() {
$(window).scroll(function() {
var navlogo = $('.nav-logo-before');
var scroll = $(window).scrollTop();
if (scroll >= 1) {
navlogo.removeClass('.nav-logo-before').addClass('nav-logo-after');
} else {
navlogo.removeClass('.nav-logo-after').addClass('nav-logo-before');
}
});
});
http://codepen.io/bradpaulp/pen/gmXOjG
There's a couple of things here:
1) You start with a .nav-logo-before class but when the logo becomes black you remove that class and then try to get the same element using a class selector that doesn't exist anymore
2) removeClass('.nav-logo-before') is different than removeClass('nev-logo-before), notice the "." in the first selector.
3) You get the element using the $('.selector')in every scroll event, this can be a performance issue, it's better to cache them on page load and then use the element stored in memory
4) It's not a good practice to listen to scroll events as this can be too performance demanding, it's usually better to use the requestAnimationFrame and then check if the scroll position has changed. Using the scroll event it could happen that you scroll up really fast and the scroll event doesn't happen at 0, so your logo won't change. With requestAnimationFrame this can't happen
$(function() {
var navlogo = $('.nav-logo');
var $window = $(window);
var oldScroll = 0;
function loop() {
var scroll = $window.scrollTop();
if (oldScroll != scroll) {
oldScroll = scroll;
if (scroll >= 1) {
navlogo.removeClass('nav-logo-before').addClass('nav-logo-after');
} else {
navlogo.removeClass('nav-logo-after').addClass('nav-logo-before');
}
}
requestAnimationFrame(loop);
}
requestAnimationFrame(loop);
});
body {
background-color: rgba(0,0,0,.2);
}
.space {
padding: 300px;
}
.nav-logo-before {
content: url(https://image.ibb.co/kYANyv/logo_test_before.png)
}
.nav-logo-after {
content: url(https://image.ibb.co/jYzFJv/logo_test_after.png)
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
<img class="nav-logo nav-logo-before">
</div>
<div class="space">
</div>
Dont need to add the dot . in front of the class name in removeClass and addClass:
Use this:
navlogo.removeClass('nav-logo-before')
Secondly, you are removing the class that you are using to get the element in the first place.
I have an updated codepen, see if this suits your needs: http://codepen.io/anon/pen/ZeaYRO
You are removing the class nav-logo-before, so the second time the function runs, it can't find any element with nav-logo-before.
Just give a second class to your navlogo element and use that on line 3.
Like this:
var navlogo = $('.second-class');
working example:
http://codepen.io/anon/pen/ryYajx
You are getting the navlogo variable using
var navlogo = $('.nav-logo-before');
but then you change the class to be 'nav-logo-after', so next time the function gets called you won't be able to select the logo using jquery as it won't have the '.nav-logo-before'class anymore.
You could add an id to the logo and use that to select it, for example.
Apart from that, removeClass('.nav-logo-before') should be removeClass('nav-logo-before') without the dot before the class name.
The problem is that you removes nav-logo-before and then you want to select element with such class but it doesn't exist.
I've rafactored you code to avert it.
Another problem is that you uses dot in removeClass('.before') while it should be removeClass('before') - without dot
$(function() {
var navlogo = $('.nav-logo');
$(window).scroll(function() {
var scroll = $(window).scrollTop();
if (scroll >= 1) {
navlogo.removeClass('before').addClass('after');
} else {
navlogo.removeClass('after').addClass('before');
}
});
});
body {
background-color: rgba(0,0,0,.2);
}
.space {
padding: 300px;
}
.before {
content: url(https://image.ibb.co/kYANyv/logo_test_before.png)
}
.after {
content: url(https://image.ibb.co/jYzFJv/logo_test_after.png)
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
<img class="nav-logo before">
</div>
<div class="space">
</div>
I'm trying to generate random div widths for each database result that's output.
The code works when it's outside the loop, but every div is the same 'random' width.
load page and all divs are 200px
refresh page and all divs are 150px
refresh page and all divs are 250px ...etc.
The trouble being, I need each individual div to be a random width, not all the same random width... for that reason I've added my javascript inside the loop in order to get a new 'random' width each time a database value is output.
And of course, it's not working!
<?php
$result = mysql_query("SELECT * from tbl_status ORDER BY tbl_status.date desc");
while($row = mysql_fetch_array($result))
{
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
<script>
$(document).ready(function(){
var x = Math.floor((Math.random()*150)+150);
$('.statusCont').width(x+'px');
});
</script>
echo'
<div class="statusCont">
<div class="statusUsr">Tom Adams - Newcastle</div>
<div class="statusTxt"><p>' . $row['status'] . '</p></div>
</div><!-- ends .statusCont -->
';}
?>
The reason that all the div's have the same random width is because the jquery class selector $('.statusCont') will return all elements with that class. So when your loop prints out the last selector it applies to all of the previous loaded elements.
Instead of including the javascript in the php while loop you can just write a script in the head that will affect the page after it's loaded
$(document).ready(function () {
$('.statusCont').each(function () {
var x = Math.floor((Math.random() * 150) + 150);
$(this).width(x);
});
);
Pleasantries
I've been playing around with this idea for a couple of days but can't seem to get a good grasp of it. I feel I'm almost there, but could use some help. I'm probably going to slap myself right in the head when I get an answer.
Actual Problem
I have a series of <articles> in my <section>, they are generated with php (and TWIG). The <article> tags have an image and a paragraph within them. On the page, only the image is visible. Once the user clicks on the image, the article expands horizontally and the paragraph is revealed. The article also animates left, thus taking up the entire width of the section and leaving all other articles hidden behind it.
I have accomplished this portion of the effect without problem. The real issue is getting the article back to where it originally was. Within the article is a "Close" <button>. Once the button is clicked, the effect needs to be reversed (ie. The article returns to original size, only showing the image, and returns to its original position.)
Current Theory
I think I need to retrieve the offset().left information from each article per section, and make sure it's associated with its respective article, so that the article knows where to go once the "Close" button is clicked. I'm of course open to different interpretations.
I've been trying to use the $.each, each(), $.map, map() and toArray() functions to know avail.
Actual Code
/*CSS*/
section > article.window {
width:170px;
height:200px;
padding:0;
margin:4px 0 0 4px;
position:relative;
float:left;
overflow:hidden;
}
section > article.window:nth-child(1) {margin-left:0;}
<!--HTML-->
<article class="window">
<img alt="Title-1" />
<p><!-- I'm a paragraph filled with text --></p>
<button class="sClose">Close</button>
</article>
<article class="window">
<!-- Ditto + 2 more -->
</article>
Failed Attempt Example
function winSlide() {
var aO = $(this).parent().offset()
var aOL = aO.left
var dO = $(this).offset()
var dOL = dO.left
var dOT = dO.top
var adTravel = dOL-aOL
$(this).addClass('windowOP');
$(this).children('div').animate({left:-(adTravel-3)+'px', width:'740px'},250)
$(this).children('div').append('<button class="sClose">Close</button>');
$(this).unbind('click', winSlide);
}
$('.window').on('click', winSlide)
$('.window').on('click', 'button.sClose', function() {
var wW = $(this).parents('.window').width()
var aO = $(this).parents('section').offset()
var aOL = aO.left
var pOL = $(this).parents('.window').offset().left
var apTravel = pOL - aOL
$(this).parent('div').animate({left:'+='+apTravel+'px'},250).delay(250, function() {$(this).animate({width:wW+'px'},250); $('.window').removeClass('windowOP');})
$('.window').bind('click', winSlide)
})
Before you go scratching your head, I have to make a note that this attempt involved an extra div within the article. The idea was to have the article's overflow set to visible (.addclass('windowOP')) with the div moving around freely. This method actually did work... almost. The animation would fail after it fired off a second time. Also for some reason when closing the first article, the left margin was property was ignored.
ie.
First time a window is clicked: Performs open animation flawlessly
First time window's close button is clicked: Performs close animation flawlessly, returns original position
Second time SAME window is clicked: Animation fails, but opens to correct size
Second time window's close button is clicked (if visible): Nothing happens
Thank you for your patience. If you need anymore information, just ask.
EDIT
Added a jsfiddle after tinkering with Flambino's code.
http://jsfiddle.net/6RV88/66/
The articles that are not clicked need to remain where they are. Having problems achieving that now.
If you want to go for storing the offsets, you can use jQuery's .data method to store data "on" the elements and retrieve it later:
// Store offset before any animations
// (using .each here, but it could also be done in a click handler,
// before starting the animation)
$(".window").each(function () {
$(this).data("closedOffset", $(this).position());
});
// Retrieve the offsets later
$('.window').on('click', 'button.sClose', function() {
var originalOffset = $(this).data("originalOffset");
// ...
});
Here's a (very) simple jsfiddle example
Update: And here's a more fleshed-out one
Big thanks to Flambino
I was able to create the effect desired. You can see it here: http://jsfiddle.net/gck2Y/ or you can look below to see the code and some explanations.
Rather than having each article's offset be remembered, I used margins on the clicked article's siblings. It's not exactly pretty, but it works exceptionally well.
<!-- HTML -->
<section>
<article>Click!</article>
<article>Me Too</article>
<article>Me Three</article>
<article>I Aswell</article>
</section>
/* CSS */
section {
position: relative;
width: 404px;
border: 1px solid #000;
height: 100px;
overflow:hidden
}
article {
height:100px;
width:100px;
position: relative;
float:left;
background: green;
border-right:1px solid orange;
}
.expanded {z-index:2;}
//Javascript
var element = $("article");
element.on("click", function () {
if( !$(this).hasClass("expanded") ) {
$(this).addClass("expanded");
$(this).data("originalOffset", $(this).offset().left);
element.data("originalSize", {
width: element.width(),
height: element.height()
});
var aOffset = $(this).data("originalOffset");
var aOuterWidth = $(this).outerWidth();
if(!$(this).is('article:first-child')){
$(this).prev().css('margin-right',aOuterWidth)
} else {
$(this).next().css('margin-left',aOuterWidth)
}
$(this).css({'position':'absolute','left':aOffset});
$(this).animate({
left: 0,
width: "100%"
}, 500);
} else {
var offset = $(this).data("originalOffset");
var size = $(this).data("originalSize");
$(this).animate({
left: offset + "px",
width: size.width + "px"
}, 500, function () {
$(this).removeClass("expanded");
$(this).prev().css('margin-right','0')
$(this).next().css('margin-left','0')
element.css({'position':'relative','left':0});
});
}
});