Subversion Repositories SmartDukaan

/*

 * typeahead.js

 * https://github.com/twitter/typeahead.js

 * Copyright 2013-2014 Twitter, Inc. and other contributors; Licensed MIT

 */

var Dataset = (function() {

  'use strict';

  var datasetKey = 'ttDataset', valueKey = 'ttValue', datumKey = 'ttDatum';

  // constructor

  // -----------

  function Dataset(o) {

    o = o || {};

    o.templates = o.templates || {};

    if (!o.source) {

      $.error('missing source');

    }

    if (o.name && !isValidName(o.name)) {

      $.error('invalid dataset name: ' + o.name);

    }

    // tracks the last query the dataset was updated for

    this.query = null;

    this.highlight = !!o.highlight;

    this.name = o.name || _.getUniqueId();

    this.source = o.source;

    this.displayFn = getDisplayFn(o.display || o.displayKey);

    this.templates = getTemplates(o.templates, this.displayFn);

    this.$el = $(html.dataset.replace('%CLASS%', this.name));

  }

  // static methods

  // --------------

  Dataset.extractDatasetName = function extractDatasetName(el) {

    return $(el).data(datasetKey);

  };

  Dataset.extractValue = function extractDatum(el) {

    return $(el).data(valueKey);

  };

  Dataset.extractDatum = function extractDatum(el) {

    return $(el).data(datumKey);

  };

  // instance methods

  // ----------------

  _.mixin(Dataset.prototype, EventEmitter, {

    // ### private

    _render: function render(query, suggestions) {

      if (!this.$el) { return; }

      var that = this, hasSuggestions;

      this.$el.empty();

      hasSuggestions = suggestions && suggestions.length;

      if (!hasSuggestions && this.templates.empty) {

        this.$el

        .html(getEmptyHtml())

        .prepend(that.templates.header ? getHeaderHtml() : null)

        .append(that.templates.footer ? getFooterHtml() : null);

      }

      else if (hasSuggestions) {

        this.$el

        .html(getSuggestionsHtml())

        .prepend(that.templates.header ? getHeaderHtml() : null)

        .append(that.templates.footer ? getFooterHtml() : null);

      }

      this.trigger('rendered');

      function getEmptyHtml() {

        return that.templates.empty({ query: query, isEmpty: true });

      }

      function getSuggestionsHtml() {

        var $suggestions, nodes;

        $suggestions = $(html.suggestions).css(css.suggestions);

        // jQuery#append doesn't support arrays as the first argument

        // until version 1.8, see http://bugs.jquery.com/ticket/11231

        nodes = _.map(suggestions, getSuggestionNode);

        $suggestions.append.apply($suggestions, nodes);

        that.highlight && highlight({

          className: 'tt-highlight',

          node: $suggestions[0],

          pattern: query

        });

        return $suggestions;

        function getSuggestionNode(suggestion) {

          var $el;

          $el = $(html.suggestion)

          .append(that.templates.suggestion(suggestion))

          .data(datasetKey, that.name)

          .data(valueKey, that.displayFn(suggestion))

          .data(datumKey, suggestion);

          $el.children().each(function() { $(this).css(css.suggestionChild); });

          return $el;

        }

      }

      function getHeaderHtml() {

        return that.templates.header({

          query: query,

          isEmpty: !hasSuggestions

        });

      }

      function getFooterHtml() {

        return that.templates.footer({

          query: query,

          isEmpty: !hasSuggestions

        });

      }

    },

    // ### public

    getRoot: function getRoot() {

      return this.$el;

    },

    update: function update(query) {

      var that = this;

      this.query = query;

      this.canceled = false;

      this.source(query, render);

      function render(suggestions) {

        // if the update has been canceled or if the query has changed

        // do not render the suggestions as they've become outdated

        if (!that.canceled && query === that.query) {

          that._render(query, suggestions);

        }

      }

    },

    cancel: function cancel() {

      this.canceled = true;

    },

    clear: function clear() {

      this.cancel();

      this.$el.empty();

      this.trigger('rendered');

    },

    isEmpty: function isEmpty() {

      return this.$el.is(':empty');

    },

    destroy: function destroy() {

      this.$el = null;

    }

  });

  return Dataset;

  // helper functions

  // ----------------

  function getDisplayFn(display) {

    display = display || 'value';

    return _.isFunction(display) ? display : displayFn;

    function displayFn(obj) { return obj[display]; }

  }

  function getTemplates(templates, displayFn) {

    return {

      empty: templates.empty && _.templatify(templates.empty),

      header: templates.header && _.templatify(templates.header),

      footer: templates.footer && _.templatify(templates.footer),

      suggestion: templates.suggestion || suggestionTemplate

    };

    function suggestionTemplate(context) {

      return '<p>' + displayFn(context) + '</p>';

    }

  }

  function isValidName(str) {

    // dashes, underscores, letters, and numbers

    return (/^[_a-zA-Z0-9-]+$/).test(str);

  }

})();