Location.hash causes infinite loop - javascript

I am using location.hash in javascript, to allow the user to switch between ajax screens (divs that are added and removed dynamically within the same html page).
The problem is, when I update location.hash by javascript, the window listener immediately fires! I need this event to fire only when the back button is actually clicked, not when I change the history by javascript.
My window listener code:
window.onhashchange = function() {
var s;
if (location.hash.length > 0) {
s = parseInt(location.hash.replace('#',''),10);
} else {
s = 1;
}
main.showScreen(s);
}
And my screen update code:
main.showScreen = function(i) {
// allow the back button to switch between screens
location.hash = i;
// but setting location.hash causes this same function to fire again!
//
// here follows the code that adds a new div with new text content
// ...
}
To clarify: showScreen can be called from anywhere in the application, for example by clicking a "next" button somewhere on the page.

In your main.showScreen function, you can:
if (location.hash != i)
location.hash = i;
OR, you can set up a document-scoped variable with the last hash value.
var lastHash = -1;
window.onhashchange = function() {
var s;
if (location.hash.length > 0) {
s = parseInt(location.hash.replace('#',''),10);
} else {
s = 1;
}
if (lastHash != s) {
lastHash = s;
main.showScreen(s);
}
}

Related

How do I change the name of the button and save it when reloading the page with javascript

I have a page with a button that when I click on it it changes but if I reload the page it returns as it is without changing
html
<button onload="form1.reset();" class="button" id="movetool10" onclick="movetool10();stoptool10()">حجز</button>
javascript
var clickCounter10 = 0;
var movetool10 = document.getElementById('movetool10')
movetool10.onclick = function() {
clickCounter10++;
if (clickCounter10 ===2) {
clickCounter10 = 0;
document.getElementById('movetool10').innerHTML = 'click !';
}
else {
document.getElementById('movetool10').innerHTML = 'click me';
}
};
You can make use of localStorage, save the last counter value there and fetch it in the begining, if it exists, use it. Otherwise, initialize the counter with 0 for first time render (or someone clears the localStorage). Please note that this is only on client side, so if the user clears the localStorage, the counter will be reinitialised.
Right now, the button shows up from its last state. It is toggling between the two states, you can change the logic however you want, but this is how you can make use of localStorage.
JSFiddle
var clickCounter10 = window.localStorage.getItem('clickCounter10') || 0;
var movetool10 = document.getElementById('movetool10');
changeBtn();
movetool10.onclick = function() {
clickCounter10++;
window.localStorage.setItem('clickCounter10', clickCounter10);
changeBtn();
};
function changeBtn() {
clickCounter10 = parseInt(clickCounter10, 10);
if (clickCounter10 === 2) {
clickCounter10 = 0;
document.getElementById('movetool10').innerHTML = 'click !';
} else if(clickCounter10 !== 0) {
document.getElementById('movetool10').innerHTML = 'click me';
}
}

How to keep Skrollr-Menu at an even speed?

I'm using Skrollr-menu to animate down a page on a button press using the following
HTML
<div class="trigger-scroll left">></div>
... the page i want to reveal, using scrolling ...
<section id="End" class="scroll-here">
<div class="hsContainer bottom"></div>
</section>
JavaScript
var s = skrollr.init();
skrollr.menu.init(s, {
animate: true,
//How long the animation should take in ms.
duration: function(currentTop, targetTop) {
//By default, the duration is hardcoded at 500ms.
return 18000;
//But you could calculate a value based on the current scroll position (`currentTop`) and the target scroll position (`targetTop`).
//return Math.abs(currentTop - targetTop) * 10;
},
//This event is triggered right before we jump/animate to a new hash.
change: function(newHash, newTopPosition) {
//Do stuff
},
//Add hash link (e.g. `#foo`) to URL or not.
updateUrl: false //defaults to `true`.
});
What happens when I click the button is that it works, that is not the problem.
The problem is that it seems to change speed as skrollr-menu animates the page. It starts off quite quickly, which means that the first few elements on the page (about the first 2000px) flash past without being readable. Then the speed evens out and is fine right until the last 3000px (approximately) where skrollr-menu is very slow. What I want is for the click of the button to resemble holding the down arrow on the keyboard or the scroll sidebar, which by default it seems skrollr-menu does not do.
I've tried using math equations to change the speed but the issue persists no matter what i try, and there doesn't seem to be any "simple" way to change the acceleration speed, and I suspect the problem is somewhere within the Skrollr.menu.js file, but I can't see where.
Is there any way which I can make the scrolling an even speed, rather than fast at the start and slow at the end?
Note: I'm not very experienced in JavaScript or jQuery, so it's probably something simple I've overlooked.
skrollr menu on github
https://github.com/Prinzhorn/skrollr-menu
Skrollr.menu.js
/*!
* Plugin for skrollr.
* This plugin makes hashlinks scroll nicely to their target position.
*
* Alexander Prinzhorn - https://github.com/Prinzhorn/skrollr
*
* Free to use under terms of MIT license
*/
(function(document, window) {
'use strict';
var DEFAULT_DURATION = 500;
var DEFAULT_EASING = 'sqrt';
var DEFAULT_SCALE = 1;
var MENU_TOP_ATTR = 'data-menu-top';
var MENU_OFFSET_ATTR = 'data-menu-offset';
var MENU_DURATION_ATTR = 'data-menu-duration';
var MENU_IGNORE_ATTR = 'data-menu-ignore';
var skrollr = window.skrollr;
var history = window.history;
var supportsHistory = !!history.pushState;
/*
Since we are using event bubbling, the element that has been clicked
might not acutally be the link but a child.
*/
var findParentLink = function(element) {
//We reached the top, no link found.
if(element === document) {
return false;
}
//Yay, it's a link!
if(element.tagName.toUpperCase() === 'A') {
return element;
}
//Maybe the parent is a link.
return findParentLink(element.parentNode);
};
/*
Handle the click event on the document.
*/
var handleClick = function(e) {
//Only handle left click.
if(e.which !== 1 && e.button !== 0) {
return;
}
var link = findParentLink(e.target);
//The click did not happen inside a link.
if(!link) {
return;
}
if(handleLink(link)) {
e.preventDefault();
}
};
/*
Handles the click on a link. May be called without an actual click event.
When the fake flag is set, the link won't change the url and the position won't be animated.
*/
var handleLink = function(link, fake) {
var hash;
//When complexLinks is enabled, we also accept links which do not just contain a simple hash.
if(_complexLinks) {
//The link points to something completely different.
if(link.hostname !== window.location.hostname) {
return false;
}
//The link does not link to the same page/path.
if(link.pathname !== document.location.pathname) {
return false;
}
hash = link.hash;
} else {
//Don't use the href property (link.href) because it contains the absolute url.
hash = link.getAttribute('href');
}
//Not a hash link.
if(!/^#/.test(hash)) {
return false;
}
//The link has the ignore attribute.
if(!fake && link.getAttribute(MENU_IGNORE_ATTR) !== null) {
return false;
}
//Now get the targetTop to scroll to.
var targetTop;
var menuTop;
//If there's a handleLink function, it overrides the actual anchor offset.
if(_handleLink) {
menuTop = _handleLink(link);
}
//If there's a data-menu-top attribute and no handleLink function, it overrides the actual anchor offset.
else {
menuTop = link.getAttribute(MENU_TOP_ATTR);
}
if(menuTop !== null) {
//Is it a percentage offset?
if(/p$/.test(menuTop)) {
targetTop = (menuTop.slice(0, -1) / 100) * document.documentElement.clientHeight;
} else {
targetTop = +menuTop * _scale;
}
} else {
var scrollTarget = document.getElementById(hash.substr(1));
//Ignore the click if no target is found.
if(!scrollTarget) {
return false;
}
targetTop = _skrollrInstance.relativeToAbsolute(scrollTarget, 'top', 'top');
var menuOffset = scrollTarget.getAttribute(MENU_OFFSET_ATTR);
if(menuOffset !== null) {
targetTop += +menuOffset;
}
}
if(supportsHistory && _updateUrl && !fake) {
history.pushState({top: targetTop}, '', hash);
}
var menuDuration = parseInt(link.getAttribute(MENU_DURATION_ATTR), 10);
var animationDuration = _duration(_skrollrInstance.getScrollTop(), targetTop);
if(!isNaN(menuDuration)) {
animationDuration = menuDuration;
}
//Trigger the change if event if there's a listener.
if(_change) {
_change(hash, targetTop);
}
//Now finally scroll there.
if(_animate && !fake) {
_skrollrInstance.animateTo(targetTop, {
duration: animationDuration,
easing: _easing
});
} else {
defer(function() {
_skrollrInstance.setScrollTop(targetTop);
});
}
return true;
};
var jumpStraightToHash = function() {
if(window.location.hash && document.querySelector) {
var link = document.querySelector('a[href="' + window.location.hash + '"]');
if(!link) {
// No link found on page, so we create one and then activate it
link = document.createElement('a');
link.href = window.location.hash;
}
handleLink(link, true);
}
};
var defer = function(fn) {
window.setTimeout(fn, 1);
};
/*
Global menu function accessible through window.skrollr.menu.init.
*/
skrollr.menu = {};
skrollr.menu.init = function(skrollrInstance, options) {
_skrollrInstance = skrollrInstance;
options = options || {};
_easing = options.easing || DEFAULT_EASING;
_animate = options.animate !== false;
_duration = options.duration || DEFAULT_DURATION;
_handleLink = options.handleLink;
_scale = options.scale || DEFAULT_SCALE;
_complexLinks = options.complexLinks === true;
_change = options.change;
_updateUrl = options.updateUrl !== false;
if(typeof _duration === 'number') {
_duration = (function(duration) {
return function() {
return duration;
};
}(_duration));
}
//Use event bubbling and attach a single listener to the document.
skrollr.addEvent(document, 'click', handleClick);
if(supportsHistory) {
skrollr.addEvent(window, 'popstate', function(e) {
var state = e.state || {};
var top = state.top || 0;
defer(function() {
_skrollrInstance.setScrollTop(top);
});
}, false);
}
jumpStraightToHash();
};
//Expose the handleLink function to be able to programmatically trigger clicks.
skrollr.menu.click = function(link) {
//We're not assigning it directly to `click` because of the second ("private") parameter.
handleLink(link);
};
//Private reference to the initialized skrollr.
var _skrollrInstance;
var _easing;
var _duration;
var _animate;
var _handleLink;
var _scale;
var _complexLinks;
var _change;
var _updateUrl;
//In case the page was opened with a hash, prevent jumping to it.
//http://stackoverflow.com/questions/3659072/jquery-disable-anchor-jump-when-loading-a-page
defer(function() {
if(window.location.hash) {
window.scrollTo(0, 0);
}
});
}(document, window));
The problem was the easing function found here
//Now finally scroll there.
if(_animate && !fake) {
_skrollrInstance.animateTo(targetTop, {
duration: animationDuration,
easing: _easing
});
} else {
defer(function() {
_skrollrInstance.setScrollTop(targetTop);
});
}
return true;
It seems that, even though Skrollr states that easing's default is linear (no easing), the default is ACTUALLY set to sqrt (or at least it was in my case). The problem can be solved by forcing easing to linear in skrollr.menu.init, or chaning the skrollr.menu.js file to remove easing from the function. The first of these two solutions is cleaner, and won't cause issues later.
skrollr.menu.init(s, {
duration: function(currentTop, targetTop) {return 20000;},
easing: 'linear'
});

Kendo Grid: Retaining navigational cell after a datasource sync

this is similar to a previous post where I wanted to sync my data source when the user changes rows in the grid (exactly as Access saves out a record)
In the post above am am shown how to do this when the user tabs into a new cell as follows...
function refreshFix1() {
kendo.ui.Grid.fn.refresh = (function (refresh) {
return function (e) {
this._refreshing = true;
refresh.call(this, e);
this._refreshing = false;
}
})(kendo.ui.Grid.fn.refresh);
kendo.ui.Grid.fn.current = (function (current) {
return function (element) {
// assuming element is td element, i.e. cell selection
if (!this._refreshing && element) {
this._lastFocusedCellIndex = $(element).index();
this._lastFocusedUid = $(element).closest("tr").data("uid");
// Added this For navigation mode
this._lastNavigationCell = this.tbody.find("tr:last td:last");
}
return current.call(this, element);
}
})(kendo.ui.Grid.fn.current);
kendo.ui.Grid.fn.refocusLastEditedCell = function () {
if (this._lastFocusedUid) {
var row = $(this.tbody).find("tr[data-uid='" + this._lastFocusedUid + "']");
var cell = $(row).children().eq(this._lastFocusedCellIndex);
this.editCell(cell);
}
};
The above gives us a function we can call (refocusLastEditedCell) after we sync the data source, and seems to work great.
I now want to do the same for when the grid is in Navigation mode. Following the above example, and the doco here , I added the following...
// Call this to go back to a cell in *navigation* mode
kendo.ui.Grid.fn.refocusLastNavigatedCell = function () {
var self = this;
if (this._lastNavigationCell) {
// try see if calling "async" using setTimeout will help
setTimeout (function(){
console.log("going back to navigation cell");
self.current(this._lastNavigationCell);
self.table.focus();
}, 10)
}
};
I then have the following code to call sync on the datasource...
vm.gridData.sync();
if (vm.editMode){
/ Go back to edit cell
grid.refocusLastEditedCell()
} else{
// Go back to navigation cell
grid.refocusLastNavigatedCell();
};
}
(full example here)
Unfortunately I do not seem to be going back to the same cell, it again just jumps to the top left cell.
Any ideas how to get it to work in this situation would be greatly appreciated.
Thanks in advance for any help!
You need to use the row uid and cell index as done in the original code; the <td> element you're trying to focus doesn't exist anymore once the grid gets rerendered. So you could do this:
kendo.ui.Grid.fn.current = (function (current) {
return function (element) {
// assuming element is td element, i.e. cell selection
if (!this._refreshing && element) {
this._lastFocusedCellIndex = $(element).index();
this._lastFocusedUid = $(element).closest("tr").data("uid");
// For navigation mode
var cell = current.call(this, element);
this._lastNavigationCellIndex = $(cell).index();
this._lastNavigationCellUid = $(cell).closest("tr").data("uid");
}
return current.call(this, element);
}
})(kendo.ui.Grid.fn.current);
and use it:
kendo.ui.Grid.fn.refocusLastNavigatedCell = function () {
if (this._lastNavigationCellUid) {
var row = $(this.tbody).find("tr[data-uid='" +
this._lastNavigationCellUid + "']");
var cell = $(row).children().eq(this._lastNavigationCellIndex);
this.current(cell);
}
};
You've got so many customizations now, you may want to extend the grid itself instead of replacing its methods one by one.
By the way, you could probably integrate all of this in the refresh method, so you don't have to explicitly call it:
kendo.ui.Grid.fn.refresh = (function (refresh) {
return function (e) {
this._refreshing = true;
refresh.call(this, e);
this._refreshing = false;
if (!this.options.editable) {
this.refocusLastNavigatedCell();
} else {
this.refocusLastEditedCell()
}
}
})(kendo.ui.Grid.fn.refresh);
I didn't understand why you want to refocus
this.tbody.find("tr:last td:last");
so I changed it for the (demo).

Android + jQuery - second on swipeleft wont execute

I have to do some Special things for my Webpage to work on Android the correct way. Some Images are displayed (one visible, the other unvisible) and through swipe it should be possible to Change them. No Problem so far on all OS.
But it also should be possible to zoom. Now Android starts to be Buggy. It stops the zoom-gesture because of the swipe callback. The callback itself doesn't Change the page because the view is zoomed, so there should be no break.
Now I work arround through turning my swipeleft and swiperight off while two fingers touching the Display, and tourning back on if the fingers leave the Display.
On First run I can swipe, then I can zoom with no break, but then I can't swipe anymore. The function to set the callbacks back on again is called, it set's the callbacks, but they won't be executed...
Here's the code:
app.utils.scroll = (function(){
var $viewport = undefined;
var swipeDisabled = false;
var init = function(){
$viewport = $('#viewport');
$viewport.mousewheel(mayChangePage);
// On touchstart with two fingers, remove the swipe listeners.
$viewport.on('touchstart', function (e) {
if (e.originalEvent.touches.length > 1) {
removeSwipe();
swipeDisabled = true;
}
});
// On touchend, re-define the swipe listeners, if they where removed through two-finger-gesture.
$viewport.on('touchend', function (e) {
if (swipeDisabled === true) {
swipeDisabled = false;
initSwipe();
}
});
initSwipe();
}
var mayChangePage = function(e){
// If page is not zoomed, change page (next or prev).
if (app.utils.zoom.isZoomed() === false) {
if (e.deltaY > 0) {
app.utils.pagination.prev(e);
} else {
app.utils.pagination.next(e);
}
}
// Stop scrolling page through mouse wheel.
e.preventDefault();
e.stopPropagation();
};
var next = function (e) {
// If page is not zoomed, switch to next page.
if (app.utils.zoom.isZoomed() === false) {
app.utils.pagination.next(e);
}
};
var prev = function (e) {
// If page is not zoomed, switch to prev page.
if (app.utils.zoom.isZoomed() === false) {
app.utils.pagination.prev(e);
}
};
var initSwipe = function () {
// Listen to swipeleft / swiperight-Event to change page.
$viewport.on('swipeleft.next', next);
$viewport.on('swiperight.prev', prev);
};
var removeSwipe = function () {
// Remove listen to swipeleft / swiperight-Event for changing page to prevent android-bug.
$viewport.off('swipeleft.next');
$viewport.off('swiperight.prev');
};
$(document).ready(init);
}());
Pastebin
Any ideas what I can do to get the Events back on again?
Thanks for all Ideas.
Regards
lippoliv
Fixed it:
jQuery Mobile itself prevents the swipe Event if an handler is registered, to kill an "scroll".
So I overwrote the $.event.special.swipe.scrollSupressionThreshold value and set it to 10000, to prevent jQueryMobile's preventDefault-call:
$.event.special.swipe.scrollSupressionThreshold = 10000;
Now my Code Looks like
app.utils.scroll = (function(){
var $viewport = undefined;
var swipeDisabled = false;
var init = function(){
$viewport = $('#viewport');
$viewport.mousewheel(mayChangePage);
// See #23.
$.event.special.swipe.scrollSupressionThreshold = 10000;
// Listen to swipeleft / swiperight-Event to change page.
$viewport.on('swipeleft.next', next);
$viewport.on('swiperight.prev', prev);
}
var mayChangePage = function(e){
// If page is not zoomed, change page (next or prev).
if (app.utils.zoom.isZoomed() === false) {
if (e.deltaY > 0) {
app.utils.pagination.prev(e);
} else {
app.utils.pagination.next(e);
}
}
// Stop scrolling page through mouse wheel.
e.preventDefault();
e.stopPropagation();
};
var next = function (e) {
// If page is not zoomed, switch to next page.
if (app.utils.zoom.isZoomed() === false) {
app.utils.pagination.next(e);
}
};
var prev = function (e) {
// If page is not zoomed, switch to prev page.
if (app.utils.zoom.isZoomed() === false) {
app.utils.pagination.prev(e);
}
};
$(document).ready(init);
}());
Thanks to Omar- who wrote with me several minutes / hours in the jquery IRC and gave some suggestions regarding overwriting Standard values for jQueryMobile.

Firing a modal manually that normally fires when a link is clicked

Im working with some JS code, since Im not front developer im having some issues to figuring out how to trigger an event on JS that normally fires when a link is clicked.
This is the link:
Demo
And the JS function that intercept the click on that link is:
(function (global) {
'use strict';
// Storage variable
var modal = {};
// Store for currently active element
modal.lastActive = undefined;
modal.activeElement = undefined;
// Polyfill addEventListener for IE8 (only very basic)
modal._addEventListener = function (element, event, callback) {
if (element.addEventListener) {
element.addEventListener(event, callback, false);
} else {
element.attachEvent('on' + event, callback);
}
};
// Hide overlay when ESC is pressed
modal._addEventListener(document, 'keyup', function (event) {
var hash = window.location.hash.replace('#', '');
// If hash is not set
if (hash === '' || hash === '!') {
return;
}
// If key ESC is pressed
if (event.keyCode === 27) {
window.location.hash = '!';
if (modal.lastActive) {
return false;
}
// Unfocus
modal.removeFocus();
}
}, false);
// Convenience function to trigger event
modal._dispatchEvent = function (event, modal) {
var eventTigger;
if (!document.createEvent) {
return;
}
eventTigger = document.createEvent('Event');
eventTigger.initEvent(event, true, true);
eventTigger.customData = { 'modal': modal };
document.dispatchEvent(eventTigger);
};
// When showing overlay, prevent background from scrolling
modal.mainHandler = function () {
var hash = window.location.hash.replace('#', '');
var modalElement = document.getElementById(hash);
var htmlClasses = document.documentElement.className;
var modalChild;
// If the hash element exists
if (modalElement) {
// Get first element in selected element
modalChild = modalElement.children[0];
// When we deal with a modal and body-class `has-overlay` is not set
if (modalChild && modalChild.className.match(/modal-inner/) &&
!htmlClasses.match(/has-overlay/)) {
// Set an html class to prevent scrolling
//document.documentElement.className += ' has-overlay';
// Mark modal as active
modalElement.className += ' is-active';
modal.activeElement = modalElement;
// Set the focus to the modal
modal.setFocus(hash);
// Fire an event
modal._dispatchEvent('cssmodal:show', modal.activeElement);
}
} else {
document.documentElement.className =
htmlClasses.replace(' has-overlay', '');
// If activeElement is already defined, delete it
if (modal.activeElement) {
modal.activeElement.className =
modal.activeElement.className.replace(' is-active', '');
// Fire an event
modal._dispatchEvent('cssmodal:hide', modal.activeElement);
// Reset active element
modal.activeElement = null;
// Unfocus
modal.removeFocus();
}
}
};
modal._addEventListener(window, 'hashchange', modal.mainHandler);
modal._addEventListener(window, 'load', modal.mainHandler);
/*
* Accessibility
*/
// Focus modal
modal.setFocus = function () {
if (modal.activeElement) {
// Set element with last focus
modal.lastActive = document.activeElement;
// New focussing
modal.activeElement.focus();
}
};
// Unfocus
modal.removeFocus = function () {
if (modal.lastActive) {
modal.lastActive.focus();
}
};
// Export CSSModal into global space
global.CSSModal = modal;
}(window));
How can i call the function that gets called when the user clicks the link but manually on my page, something like <script>firelightbox(parameters);</script>
Using jQuery will solve this easily
$('.selector').click();
but plain old JavaScript may also have a solution for you
Let's just give your anchor element an Id (to keep things simple)
<a id="anchorToBeClicked" href="#modal-text" class="call-modal" title="Clicking this link shows the modal">Demo</a>
Let's create a function that simulates the click
function simulateClick() {
var evt = document.createEvent("MouseEvents");
evt.initMouseEvent("click", true, true, window,
0, 0, 0, 0, 0, false, false, false, false, 0, null);
var cb = document.getElementById("anchorToBeClicked");
cb.dispatchEvent(evt);
}
Now call this function on window.onload
window.onload = function() {
simulateClick();
};
EDIT:
Actually, the code you are using is not working on actual click event of the anchor tag, instead it relies on hash change of Url in your browser window. You can simply invoke that functionality by using
window.onload = function() {
location.hash = '#modal-text'
};
If you are using jQuery, you can trigger the clicking of a link on page load using this code:
$(document).ready(function(){
$('.call-modal').click();
});

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