set: function()

in security-admin/src/main/webapp/libs/bower/backbone/js/backbone.js [834:947]
90 lines of code
45 McCabe index (conditional complexity)

    set: function(models, options) {
      if (models == null) return;

      options = _.extend({}, setOptions, options);
      if (options.parse && !this._isModel(models)) {
        models = this.parse(models, options) || [];
      }

      var singular = !_.isArray(models);
      models = singular ? [models] : models.slice();

      var at = options.at;
      if (at != null) at = +at;
      if (at > this.length) at = this.length;
      if (at < 0) at += this.length + 1;

      var set = [];
      var toAdd = [];
      var toMerge = [];
      var toRemove = [];
      var modelMap = {};

      var add = options.add;
      var merge = options.merge;
      var remove = options.remove;

      var sort = false;
      var sortable = this.comparator && at == null && options.sort !== false;
      var sortAttr = _.isString(this.comparator) ? this.comparator : null;

      // Turn bare objects into model references, and prevent invalid models
      // from being added.
      var model, i;
      for (i = 0; i < models.length; i++) {
        model = models[i];

        // If a duplicate is found, prevent it from being added and
        // optionally merge it into the existing model.
        var existing = this.get(model);
        if (existing) {
          if (merge && model !== existing) {
            var attrs = this._isModel(model) ? model.attributes : model;
            if (options.parse) attrs = existing.parse(attrs, options);
            existing.set(attrs, options);
            toMerge.push(existing);
            if (sortable && !sort) sort = existing.hasChanged(sortAttr);
          }
          if (!modelMap[existing.cid]) {
            modelMap[existing.cid] = true;
            set.push(existing);
          }
          models[i] = existing;

        // If this is a new, valid model, push it to the `toAdd` list.
        } else if (add) {
          model = models[i] = this._prepareModel(model, options);
          if (model) {
            toAdd.push(model);
            this._addReference(model, options);
            modelMap[model.cid] = true;
            set.push(model);
          }
        }
      }

      // Remove stale models.
      if (remove) {
        for (i = 0; i < this.length; i++) {
          model = this.models[i];
          if (!modelMap[model.cid]) toRemove.push(model);
        }
        if (toRemove.length) this._removeModels(toRemove, options);
      }

      // See if sorting is needed, update `length` and splice in new models.
      var orderChanged = false;
      var replace = !sortable && add && remove;
      if (set.length && replace) {
        orderChanged = this.length !== set.length || _.some(this.models, function(m, index) {
          return m !== set[index];
        });
        this.models.length = 0;
        splice(this.models, set, 0);
        this.length = this.models.length;
      } else if (toAdd.length) {
        if (sortable) sort = true;
        splice(this.models, toAdd, at == null ? this.length : at);
        this.length = this.models.length;
      }

      // Silently sort the collection if appropriate.
      if (sort) this.sort({silent: true});

      // Unless silenced, it's time to fire all appropriate add/sort/update events.
      if (!options.silent) {
        for (i = 0; i < toAdd.length; i++) {
          if (at != null) options.index = at + i;
          model = toAdd[i];
          model.trigger('add', model, this, options);
        }
        if (sort || orderChanged) this.trigger('sort', this, options);
        if (toAdd.length || toRemove.length || toMerge.length) {
          options.changes = {
            added: toAdd,
            removed: toRemove,
            merged: toMerge
          };
          this.trigger('update', this, options);
        }
      }

      // Return the added (or merged) model (or models).
      return singular ? models[0] : models;
    },