jQuery Plupload restrict number of uploads

问题

I have been working on this code for some time now trying to get it to work properly. I want to restrict the use from uploading more that 2 images in total.

The line var upa = $('.uploader').plupload('getUploader'); it giving an error of Uncaught TypeError: Object [object Object] has no method 'plupload'

    var maxfiles=2;
    $('.uploader').each(function(){
        var $uploader = $(this);
        $uploader.pluploadQueue($.extend({
            runtimes: 'html5,flash,html4',
            url : '../admin/extras/upload.php',
            max_file_size : '2mb',
            chunk_size : '2mb',
            unique_names : true,                
            filters : [
                {title : "Image files", extensions : "jpg"}
            ],
            resize : {width : 800, height : 600, quality : 90},
            flash_swf_url : 'js/mylibs/forms/uploader/plupload.flash.swf',
            init : {
                FilesAdded: function(up, files) {
                    plupload.each(files, function(file) {
                        if (up.files.length > maxfiles) {
                            up.removeFile(file);
                        }
                        var upa = $('.uploader').plupload('getUploader');
                        var i = 0;
                        while (i<=upa.files.length) {
                            ultimo = upa.files.length;
                            if (ultimo > 1) {
                                if (i > 0) {
                                    ultimo2 = ultimo - 1;
                                    ii = i-1;
                                    if (ultimo2 != ii) {
                                        if (up.files[ultimo - 1].name == upa.files[i-1].name) {
                                            up.removeFile(file);
                                        }
                                    }
                                }
                            }
                            i++;
                        }
                    });
                    if (up.files.length >= maxfiles) {
                        $('#uploader_browse').hide("slow");
                    }
                },
                FilesRemoved: function(up, files) {
                    if (up.files.length < maxfiles) {
                        $('#uploader_browse').fadeIn("slow");
                    }
                }
            }
        }));
        $uploader.find('.plupload_button').addClass('button grey btn');
        $uploader.find('.plupload_add').addClass('icon-plus');
        $uploader.find('.plupload_start').addClass('icon-ok');
    });

The error is generated when i upload images. I don't know what I am missing but any help on this is greatly appreciated.

回答1:

What you want to achieve in the while (i<=upa.files.length) { block is not clear to me. Seems like you have several uploaders on your page, but I can't grasp the idea.

Anyway, I guess this should do the trick, as to restrict to 2 files max in a single uploader.

FilesAdded: function(up, files) {
                    var maxfiles = 2;
                    if(up.files.length > maxfiles )
                     {
                        up.splice(maxfiles);
                        alert('no more than '+maxfiles + ' file(s)');
                     }
                    if (up.files.length === maxfiles) {
                        $('#uploader_browse').hide("slow"); // provided there is only one #uploader_browse on page
                    }
                },

Hope this will help

回答2:

Good answer jbl. I tweaked your solution a bit to make it more generic, and to make the 'Add files' button reappear when needed.

uploader.bind('FilesAdded', function(up, files) {
  if (up.files.length >= up.settings.max_files) {
    up.splice(up.settings.max_files);
    $(up.settings.browse_button).hide();
  }
});

uploader.bind('FilesRemoved', function(up, files) {
  if (up.files.length < up.settings.max_files) {
    $(up.settings.browse_button).show();
  }
});

max_files is part of the pluploadQueue settings

$("#uploadBox").pluploadQueue({
  ...
  max_files: 2,
  ...
});

来源：https://stackoverflow.com/questions/15513689/jquery-plupload-restrict-number-of-uploads