gnu-social/plugins/InfiniteScroll/jquery.infinitescroll.js

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2009-08-06 06:09:19 +09:00
/*!
// Infinite Scroll jQuery plugin
// copyright Paul Irish, licensed GPL & MIT
// version 1.2.090804
// home and docs: http://www.infinite-scroll.com
*/
// todo: add preloading option.
;(function($){
$.fn.infinitescroll = function(options,callback){
// console log wrapper.
function debug(){
if (opts.debug) { window.console && console.log.call(console,arguments)}
}
// grab each selector option and see if any fail.
function areSelectorsValid(opts){
for (var key in opts){
if (key.indexOf && key.indexOf('Selector') && $(opts[key]).length === 0){
debug('Your ' + key + ' found no elements.');
return false;
}
return true;
}
}
// find the number to increment in the path.
function determinePath(path){
path.match(relurl) ? path.match(relurl)[2] : path;
// there is a 2 in the url surrounded by slashes, e.g. /page/2/
if ( path.match(/^(.*?)\b2\b(.*?$)/) ){
path = path.match(/^(.*?)\b2\b(.*?$)/).slice(1);
} else
// if there is any 2 in the url at all.
if (path.match(/^(.*?)2(.*?$)/)){
debug('Trying backup next selector parse technique. Treacherous waters here, matey.');
path = path.match(/^(.*?)2(.*?$)/).slice(1);
} else {
debug('Sorry, we couldn\'t parse your Next (Previous Posts) URL. Verify your the css selector points to the correct A tag. If you still get this error: yell, scream, and kindly ask for help at infinite-scroll.com.');
props.isInvalidPage = true; //prevent it from running on this page.
}
return path;
}
// 'document' means the full document usually, but sometimes the content of the overflow'd div in local mode
function getDocumentHeight(){
// weird doubletouch of scrollheight because http://soulpass.com/2006/07/24/ie-and-scrollheight/
return opts.localMode ? ($(props.container)[0].scrollHeight && $(props.container)[0].scrollHeight)
// needs to be document's height. (not props.container's) html's height is wrong in IE.
: $(document).height()
}
function isNearBottom(opts,props){
// distance remaining in the scroll
// computed as: document height - distance already scroll - viewport height - buffer
var pixelsFromWindowBottomToBottom = getDocumentHeight() -
(opts.localMode ? $(props.container).scrollTop() :
// have to do this bs because safari doesnt report a scrollTop on the html element
($(props.container).scrollTop() || $(props.container.ownerDocument.body).scrollTop())) -
$(opts.localMode ? props.container : window).height();
debug('math:',pixelsFromWindowBottomToBottom, props.pixelsFromNavToBottom);
// if distance remaining in the scroll (including buffer) is less than the orignal nav to bottom....
return (pixelsFromWindowBottomToBottom - opts.bufferPx < props.pixelsFromNavToBottom);
}
function showDoneMsg(){
props.loadingMsg
.find('img').hide()
.parent()
.find('div').html(opts.donetext).animate({opacity: 1},2000).fadeOut('normal');
// user provided callback when done
opts.errorCallback();
}
function infscrSetup(path,opts,props,callback){
if (props.isDuringAjax || props.isInvalidPage || props.isDone) return;
if ( opts.infiniteScroll && !isNearBottom(opts,props) ) return;
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// we dont want to fire the ajax multiple times
props.isDuringAjax = true;
// show the loading message and hide the previous/next links
props.loadingMsg.appendTo( opts.contentSelector ).show();
if(opts.infiniteScroll) $( opts.navSelector ).hide();
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// increment the URL bit. e.g. /page/3/
props.currPage++;
debug('heading into ajax',path);
// if we're dealing with a table we can't use DIVs
var box = $(opts.contentSelector).is('table') ? $('<tbody/>') : $('<div/>');
box
.attr('id','infscr-page-'+props.currPage)
.addClass('infscr-pages')
.appendTo( opts.contentSelector )
.load( path.join( props.currPage ) + ' ' + opts.itemSelector,null,function(){
// if we've hit the last page...
if (props.isDone){
showDoneMsg();
return false;
} else {
// if it didn't return anything
if (box.children().length == 0){
// fake an ajaxError so we can quit.
$.event.trigger( "ajaxError", [{status:404}] );
}
// fadeout currently makes the <em>'d text ugly in IE6
props.loadingMsg.fadeOut('normal' );
// smooth scroll to ease in the new content
if (opts.animate){
var scrollTo = $(window).scrollTop() + $('#infscr-loading').height() + opts.extraScrollPx + 'px';
$('html,body').animate({scrollTop: scrollTo}, 800,function(){ props.isDuringAjax = false; });
}
// pass in the new DOM element as context for the callback
callback.call( box[0] );
if (!opts.animate) props.isDuringAjax = false; // once the call is done, we can allow it again.
}
}); // end of load()
} // end of infscrSetup()
// lets get started.
var opts = $.extend({}, $.infinitescroll.defaults, options);
var props = $.infinitescroll; // shorthand
callback = callback || function(){};
if (!areSelectorsValid(opts)){ return false; }
// we doing this on an overflow:auto div?
props.container = opts.localMode ? this : document.documentElement;
// contentSelector we'll use for our .load()
opts.contentSelector = opts.contentSelector || this;
// get the relative URL - everything past the domain name.
var relurl = /(.*?\/\/).*?(\/.*)/;
var path = $(opts.nextSelector).attr('href');
if (!path) { debug('Navigation selector not found'); return; }
// set the path to be a relative URL from root.
path = determinePath(path);
// reset scrollTop in case of page refresh:
if (opts.localMode) $(props.container)[0].scrollTop = 0;
// distance from nav links to bottom
// computed as: height of the document + top offset of container - top offset of nav link
props.pixelsFromNavToBottom = getDocumentHeight() +
$(props.container).offset().top -
$(opts.navSelector).offset().top;
// define loading msg
props.loadingMsg = $('<div id="infscr-loading" style="text-align: center;"><img alt="Loading..." src="'+
opts.loadingImg+'" /><div>'+opts.loadingText+'</div></div>');
// preload the image
(new Image()).src = opts.loadingImg;
// set up our bindings
$(document).ajaxError(function(e,xhr,opt){
debug('Page not found. Self-destructing...');
// die if we're out of pages.
if (xhr.status == 404){
showDoneMsg();
props.isDone = true;
$(opts.localMode ? this : window).unbind('scroll.infscr');
}
});
if(opts.infiniteScroll){
// bind scroll handler to element (if its a local scroll) or window
$(opts.localMode ? this : window)
.bind('scroll.infscr', function(){ infscrSetup(path,opts,props,callback); } )
.trigger('scroll.infscr'); // trigger the event, in case it's a short page
}else{
$(opts.nextSelector).click(
function(){
infscrSetup(path,opts,props,callback);
return false;
}
);
}
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return this;
} // end of $.fn.infinitescroll()
// options and read-only properties object
$.infinitescroll = {
defaults : {
debug : false,
infiniteScroll : true,
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preload : false,
nextSelector : "div.navigation a:first",
loadingImg : "http://www.infinite-scroll.com/loading.gif",
loadingText : "<em>Loading the next set of posts...</em>",
donetext : "<em>Congratulations, you've reached the end of the internet.</em>",
navSelector : "div.navigation",
contentSelector : null, // not really a selector. :) it's whatever the method was called on..
extraScrollPx : 150,
itemSelector : "div.post",
animate : false,
localMode : false,
bufferPx : 40,
errorCallback : function(){}
},
loadingImg : undefined,
loadingMsg : undefined,
container : undefined,
currPage : 1,
currDOMChunk : null, // defined in setup()'s load()
isDuringAjax : false,
isInvalidPage : false,
isDone : false // for when it goes all the way through the archive.
};
})(jQuery);