support multiple grids

[yairEO]

in your code, you have this piece:

if(options.resize) {
    $(window).on('resize', {container: this[0]}, function(e){

please scope your events so they wouldn't collide with others code, and change it a little to:

if(options.resize) {
    $(window).on('resize.rowGrid', function(e){
      // do 'layout' for each "this" element
}

BUT, you need to take that resize event outside, and wrap the rest of your initialization code with something like:

$.fn.rowGrid = function( options ) {
    var defaults = {
      minMargin: null,
      maxMargin: null,
      resize: true,
      lastRowClass: 'last-row',
      firstItemClass: null
    };

    return this.each(function(){
        if ( this.length == 0 ) {
          console.error( 'No element found for "' + this.selector + '".' );
          return this;
        }
        if ( this.length > 1 ) {
          return this.each(
            function() {
              $(this).rowGrid( options );
            }
          );
        }

        if(options === 'appended') {
          options = this.data('grid-options');
          var $lastRow = this.children('.' + options.lastRowClass);
          var items = $lastRow.nextAll().add($lastRow);
          layout(this[0], options, items);
        } else {
          options = $.extend( {}, defaults, options );
          this.data('grid-options', options);
          layout(this[0], options);
       }
    })

        if(options.resize) {
        $(window).on('resize.rowGrid', function(e){
            this.each(function(){
                layout(this, options);
            });
        });
    }

       ....
       ....
      // rest of the code
});

[yairEO]

I would ALSO recommend to debounce your resize event and only call the layout function when the event ends. (see - http://stackoverflow.com/a/4541963/104380)

and this will maximize performance greatly, while also allowing smooth transitions to be made via CSS to the grid's items. But, you would have to give the item's parent a styled width on event layout call. do this and your plugin will rock.

[brunjo]

Multiple grids on one page are supported.

---

I am not sure whether debouncing the resize event is a good idea because you have to set a width to the container and when you decrease your window size the container can be larger then the window. Then a horizontal scrollbar appears or the layout of the page is destroyed because of the too large container for a second. This is very sloppy. I don't like it.
I think it is better to improve the performance through caching, so that the resize is faster.
BTW how many people resize their browsers? ;)

[yairEO]

well it's not about the actual resizing of the browser but rather the size change of the containing element. say, if you have a side menu and comes and goes, so when it comes in, the content area gets smaller.

also, I know multiple grids are supported, BUT the plugin has to be called for each element, and it's considered a good plugin authoring to do return this.each(function(){ to iterate the jQuery selector and run your code on each element, instead of calling the plugin manually for each of them. see example above.

Also this is a good read about layout performance with many DOM read/writes FYI :
http://wilsonpage.co.uk/preventing-layout-thrashing/

[brunjo]

BUT the plugin has to be called for each element

No! You can do something like this:
$(".container1, .container2").rowGrid(options);

It is done with the following code snippet:

if ( this.length > 1 ) {
  return this.each(
    function() {
       $(this).rowGrid( options );
    }
  );
}

[yairEO]

well my way is the correct way and your way is a hacky one, because your way is doing hacky check to see if there are more than 1 selector and then call the plugin again, and on top of the you have 2 return statements... my way is the way everybody is doing plugins..trust me I've been writing jquery plugins since 2007 and used jQuery since before that..there is a purpose of use return this.each(function(){ ...

anyway, I wouldn't want to do $(".container1, .container2").rowGrid(options); since all my containers have the exact same class, lets say I have 3 containers with the class "container" on the page.

[brunjo]

I will change it. I trust you ;)

$(".container1, .container2").rowGrid(options); was only an example to show that the plugin works with selectors which targeting more than one element. Of course the following works, too: $(".container").rowGrid(options);