pagination_support.js

/**
  @extends Ember.Mixin
 
  Implements common pagination management properties for controllers.
*/
App.PaginationSupport = Ember.Mixin.create({
 
  hasPaginationSupport: true,
 
  total: 0,

  page: 1,
 
  perPage: 30,
 
  pageRange: 3,

  actions: {
    firstPage: function() {
      if (this.get('hasNext')) { // hasNext implies hasFirst
        this.send('changePage', 1);
      }
    },

    lastPage: function() {
      if (this.get('hasNext')) { // hasPrevious implies hasLast
        this.send('changePage', this.get('totalPages'));
      }
    },

    nextPage: function() {
      if (this.get('hasNext')) {
        this.incrementProperty('page');
      }
    },
   
    previousPage: function() {
      if (this.get('hasPrevious')) {
        this.decrementProperty('page');
      }
    },

    changePage: function(page) {
      if(page != this.get('page')) {
        this.set('page', page);
      }
    },

    changePerPage: function(perPage) {
      this.set('perPage', perPage);
      this.send('firstPage');
    },

    updatePage: Ember.K 
  },

  pages: function(){
    var page = this.get('page'),
        totalPages = this.get('totalPages'),
        pageRange = this.get('pageRange'),
        windowSize = (pageRange * 2) + 1,
        pages = [];

    if(page) {
      var start = page - pageRange,
          end   = page + pageRange;

      if(start < 1) {
        start = 1;
        end = (start + windowSize > totalPages) ? totalPages : start + windowSize;
      }

      if(end > totalPages) {
        end = totalPages;
        start = (end - windowSize < 1) ? 1 : end - windowSize;
      }

      for(var i = start; i <= end; i++) {
        if(i == page) {
          pages.push({page: i, active: true});
        } else {
          pages.push({page: i});
        }
      }
    }
    
    return pages;
  }.property('page', 'total'),
 
  totalPages: function() {
    return Math.ceil(this.get('total') / this.get('perPage'));
  }.property('total', 'perPage').cacheable(),

  hasPrevious: function() {
    return this.get('page') > 1;
  }.property('page').cacheable(),
 
  hasNext: function() {
    return this.get('page') < this.get('totalPages');
  }.property('page', 'total').cacheable(),  
 
  pageDidChange: function() {
    this.send('updatePage');
  }.observes('page', 'perPage')
});