dojox/grid/enhanced/plugins/_SelectionPreserver.js

• Provides:

  • dojox.grid.enhanced.plugins._SelectionPreserver

• dojox.grid.enhanced.plugins._SelectionPreserver

  • type

    Function

  • summary

    Preserve selections across various user actions.

  • description

    When this feature turned on, Grid will try to preserve selections across various user actions, e.g. sorting, filtering etc.
    Precondition - Identifier(id) is required for store, as id is used for differentiating row items.
    Known issue - The preserved selections might be inaccurate if some unloaded rows are selected by range previously(e.g.SHIFT + click)

  • example

    
    	//To turn on this - set 'keepSelection' attribute to true
    	<div dojoType="dojox.grid.EnhancedGrid" keepSelection = true .../>

  • parameters:
    • selection: (typeof )
  • source: [view]
      this.selection = selection;
      var grid = this.grid = selection.grid;
      grid.onSelectedById = this.onSelectedById;
      this.reset();
    
    
      var oldClearData = grid._clearData;
      var _this = this;
      grid._clearData = function(){
       _this._updateMapping(!grid._noInternalMapping);
       _this._trustSelection = [];
       oldClearData.apply(grid, arguments);
      };
      this.connect(grid, '_setStore', 'reset');
      this.connect(grid, '_addItem', '_reSelectById');
      this.connect(selection, 'addToSelection', dojo.hitch(this, '_selectById', true));
      this.connect(selection, 'deselect', dojo.hitch(this, '_selectById', false));
      this.connect(selection, 'selectRange', dojo.hitch(this, '_updateMapping', true, true, false));
      this.connect(selection, 'deselectRange', dojo.hitch(this, '_updateMapping', true, false, false));
      this.connect(selection, 'deselectAll', dojo.hitch(this, '_updateMapping', true, false, true));

• dojox.grid.enhanced.plugins._SelectionPreserver._connects

  • type

    Array

  • summary

    List of all connections.

• dojox.grid.enhanced.plugins._SelectionPreserver.destroy

  • type

    Function

  • source: [view]
      this.reset();
      dojo.forEach(this._connects, dojo.disconnect);
      delete this._connects;
  • summary

• dojox.grid.enhanced.plugins._SelectionPreserver.connect

  • type

    Function

  • parameters:
    • obj: (typeof )
    • event: (typeof )
    • method: (typeof )
  • source: [view]
      var conn = dojo.connect(obj, event, this, method);
      this._connects.push(conn);
      return conn;
  • summary

    Connects specified obj/event to specified method of this object.

• dojox.grid.enhanced.plugins._SelectionPreserver.reset

  • type

    Function

  • source: [view]
      this._idMap = [];
      this._selectedById = {};
      this._trustSelection = [];
      this._defaultSelected = false;
  • summary

• dojox.grid.enhanced.plugins._SelectionPreserver._reSelectById

  • type

    Function

  • parameters:
    • item: (typeof )
    • index: (typeof )
  • source: [view]
      var s = this.selection, g = this.grid;
      if(item && g._hasIdentity){
       var id = g.store.getIdentity(item);
       if(this._selectedById[id] === undefined){
        if(!this._trustSelection[index]){
         s.selected[index] = this._defaultSelected;
        }
       }else{
        s.selected[index] = this._selectedById[id];
       }
       this._idMap.push(id);
       g.onSelectedById(id, index, s.selected[index]);
      }
  • summary

    When some rows is fetched, determine whether it should be selected.
    When this function is called, grid.selection.selected[] is not trustable.

• dojox.grid.enhanced.plugins._SelectionPreserver._selectById

  • type

    Function

  • parameters:
    • toSelect: (typeof )
    • inItemOrIndex: (typeof )
  • source: [view]
      if(this.selection.mode == 'none' || !this.grid._hasIdentity){ return; }
      var item = inItemOrIndex;
      if(typeof inItemOrIndex == "number" || typeof inItemOrIndex == "string"){
       var entry = this.grid._by_idx[inItemOrIndex];
       item = entry && entry.item;
      }
      if(item){
       var id = this.grid.store.getIdentity(item);
       this._selectedById[id] = !!toSelect;
      }else{
       this._trustSelection[inItemOrIndex] = true;
      }
  • summary

    Record selected rows by ID.

• dojox.grid.enhanced.plugins._SelectionPreserver.onSelectedById

  • type

    Function

  • parameters:
    • id: (typeof )
    • rowIndex: (typeof )
    • value: (typeof )
  • source: [view]
    }
  • summary

• dojox.grid.enhanced.plugins._SelectionPreserver._updateMapping

  • type

    Function

  • parameters:
    • trustSelection: (typeof )
    • isSelect: (typeof )
    • isForAll: (typeof )
    • from: (typeof )
    • to: (typeof )
  • source: [view]
      var s = this.selection, g = this.grid, flag = 0, unloaded = 0, i, id;
      for(i = g.rowCount - 1; i >= 0; --i){
       if(!g._by_idx[i]){
        ++unloaded;
        flag += s.selected[i] ? 1 : -1;
       }else{
        id = g._by_idx[i].idty;
        if(id && (trustSelection || this._selectedById[id] === undefined)){
         this._selectedById[id] = !!s.selected[i];
        }
       }
      }
      if(unloaded){
       this._defaultSelected = flag > 0;
      }
      if(!isForAll && from !== undefined && to !== undefined){
       isForAll = !g.usingPagination && Math.abs(to - from + 1) === g.rowCount;
      }
      // When deselectAll, make sure every thing is deselected, even if it was selected but not loaded now.
      // This occurs only when pagination's "All" is used.
      if(isForAll && !g.usingPagination){
       for(i = this._idMap.length; i >= 0; --i){
        this._selectedById[this._idMap[i]] = isSelect;
       }
      }
  • summary

    This function trys to keep the selection info updated when range selection is performed.
    1. Calculate how many unloaded rows are there;
    2. update _selectedById data if grid.selection._selected can be trusted, so loaded but unselected rows can
    be properly recorded.

• dojox.grid.enhanced.plugins._SelectionPreserver._idMap

  • summary

• dojox.grid.enhanced.plugins._SelectionPreserver._selectedById

  • summary

• dojox.grid.enhanced.plugins._SelectionPreserver._trustSelection

  • summary

• dojox.grid.enhanced.plugins._SelectionPreserver._defaultSelected

  • summary

• dojox.grid.enhanced.plugins._SelectionPreserver.selection.mode

  • summary

• dojox.grid.enhanced.plugins._SelectionPreserver.selection

  • summary

• dojox.grid.enhanced.plugins._SelectionPreserver.grid

  • summary

• dojox.grid.enhanced.plugins

  • type

    Object

  • summary

• dojox.grid.enhanced

  • type

    Object

  • summary

• dojox.grid

  • type

    Object

  • summary

• dojox

  • type

    Object

  • summary