source: Dev/trunk/src/client/dojox/grid/enhanced/plugins/Exporter.js

define([
        "dojo/_base/declare",
        "dojo/_base/array",
        "dojo/_base/lang",
        "../_Plugin",
        "../../_RowSelector",
        "../../EnhancedGrid",
        "../../cells/_base"
], function(declare, array, lang, _Plugin, _RowSelector, EnhancedGrid){

var gridCells = lang.getObject("dojox.grid.cells");

var Exporter = declare("dojox.grid.enhanced.plugins.Exporter", _Plugin, {
        // summary:
        //              Provide functions to export the grid data into a given format.
        //
        //              Acceptable plugin parameters:
        //
        //              1. exportFormatter: function(data, cell, rowIndex, item)
        //                      Provide a way to customize how data should look in exported string.
        //                      Note that usually the formatter of grid cell should not be used here (it can return HTML or even widget).
        // example:
        //      |       function onExported(exported_text){
        //      |               //custom code here...
        //      |       }
        //      |       dijit.byId("my_grid_id").exportTo("csv",        //registered export format, mandatory
        //      |               {                                                                               //the whole object is optional.
        //      |                       fetchArgs: {start:0,count:1000},        //keywordArgs for fetch, optional
        //      |                       writerArgs: {separator:';'},            //export writer specific arguments, optional
        //      |               },
        //      |               function(str){
        //      |                       //call back function, mandatory
        //      |       });
        //      |       var result = dijit.byId("my_grid_id").exportSelectedTo("table",     //registered export format, mandatory
        //      |                                                                                                               {separator:'|'} //export writer specific arguments, optional
        //      |       );
        //

        // name: String
        //              Plugin name.
        name: "exporter",
        
        constructor: function(grid, args){
                // summary:
                //              only newed by _Plugin
                // grid: EnhancedGrid
                //              The grid to plug in to.
                this.grid = grid;
                this.formatter = (args && lang.isObject(args)) && args.exportFormatter;
                this._mixinGrid();
        },
        _mixinGrid: function(){
                var g = this.grid;
                g.exportTo = lang.hitch(this, this.exportTo);
                g.exportGrid = lang.hitch(this, this.exportGrid);
                g.exportSelected = lang.hitch(this, this.exportSelected);
                g.setExportFormatter = lang.hitch(this, this.setExportFormatter);
        },
        setExportFormatter: function(formatter){
                this.formatter = formatter;
        },
        exportGrid: function(type, args, onExported){
                // summary:
                //              Export required rows(fetchArgs) to a kind of format(type)
                //              using the corresponding writer with given arguments(writerArgs),
                //              then pass the exported text to a given function(onExported).
                // tags:
                //              public
                // type: String
                //              A registered export format name
                // args: Object?
                //              includes:
                // |    {
                // |            fetchArgs: object?
                // |                    Any arguments for store.fetch
                // |            writerArgs: object?
                // |                    Arguments for the given format writer
                // |    }
                // onExported: Function(string)
                //              Call back function when export result is ready
                if(lang.isFunction(args)){
                        onExported = args;
                        args = {};
                }
                if(!lang.isString(type) || !lang.isFunction(onExported)){
                        return;
                }
                args = args || {};
                var g = this.grid, _this = this,
                        writer = this._getExportWriter(type, args.writerArgs),
                        fetchArgs = (args.fetchArgs && lang.isObject(args.fetchArgs)) ? args.fetchArgs : {},
                        oldFunc = fetchArgs.onComplete;
                if(g.store){
                        fetchArgs.onComplete = function(items, request){
                                if(oldFunc){
                                        oldFunc(items, request);
                                }
                                onExported(_this._goThroughGridData(items, writer));
                        };
                        fetchArgs.sort = fetchArgs.sort || g.getSortProps();
                        g._storeLayerFetch(fetchArgs);
                }else{
                        //Data is defined directly in the structure;
                        var start = fetchArgs.start || 0,
                                count = fetchArgs.count || -1,
                                items = [];
                        for(var i = start; i != start + count && i < g.rowCount; ++i){
                                items.push(g.getItem(i));
                        }
                        onExported(this._goThroughGridData(items, writer));
                }
        },
        exportSelected: function(type, writerArgs, onExported){
                // summary:
                //              Only export selected rows.
                // tags:
                //              public
                // type: string
                //              A registered export format name
                // writerArgs: object?
                //              Arguments for the given format writer
                // returns: string
                //              The exported string
                if(!lang.isString(type)){
                        return "";
                }
                var writer = this._getExportWriter(type, writerArgs);
                return onExported(this._goThroughGridData(this.grid.selection.getSelected(), writer));  //String
        },
        _buildRow: function(/* object */arg_obj,/* ExportWriter */writer){
                // summary:
                //              Use the given export writer(writer) to go through a single row
                //              which is given in the context object(arg_obj).
                // tags:
                //              private
                // returns:
                //              undefined
                var _this = this;
                array.forEach(arg_obj._views, function(view, vIdx){
                        arg_obj.view = view;
                        arg_obj.viewIdx = vIdx;
                        if(writer.beforeView(arg_obj)){
                                array.forEach(view.structure.cells, function(subrow, srIdx){
                                        arg_obj.subrow = subrow;
                                        arg_obj.subrowIdx = srIdx;
                                        if(writer.beforeSubrow(arg_obj)){
                                                array.forEach(subrow, function(cell, cIdx){
                                                        if(arg_obj.isHeader && _this._isSpecialCol(cell)){
                                                                arg_obj.spCols.push(cell.index);
                                                        }
                                                        arg_obj.cell = cell;
                                                        arg_obj.cellIdx = cIdx;
                                                        writer.handleCell(arg_obj);
                                                });
                                                writer.afterSubrow(arg_obj);
                                        }
                                });
                                writer.afterView(arg_obj);
                        }
                });
        },
        _goThroughGridData: function(/* Array */items,/* ExportWriter */writer){
                // summary:
                //              Use the given export writer(writer) to go through the grid structure
                //              and the given rows(items), then return the writer output.
                // tags:
                //              private
                var grid = this.grid,
                        views = array.filter(grid.views.views, function(view){
                                return !(view instanceof _RowSelector);
                        }),
                        arg_obj = {
                                'grid': grid,
                                'isHeader': true,
                                'spCols': [],
                                '_views': views,
                                'colOffset': (views.length < grid.views.views.length ? -1 : 0)
                        };
                //go through header
                if(writer.beforeHeader(grid)){
                        this._buildRow(arg_obj,writer);
                        writer.afterHeader();
                }
                //go through content
                arg_obj.isHeader = false;
                if(writer.beforeContent(items)){
                        array.forEach(items, function(item, rIdx){
                                arg_obj.row = item;
                                arg_obj.rowIdx = rIdx;
                                if(writer.beforeContentRow(arg_obj)){
                                        this._buildRow(arg_obj, writer);
                                        writer.afterContentRow(arg_obj);
                                }
                        }, this);
                        writer.afterContent();
                }
                return writer.toString();
        },
        _isSpecialCol: function(/* dojox.grid.__CellDef */header_cell){
                // summary:
                //              Row selectors and row indexes should be recognized and handled separately.
                // tags:
                //              private
                return header_cell.isRowSelector || header_cell instanceof gridCells.RowIndex;  //Boolean
        },
        _getExportWriter: function(/* string */ fileType, /* object? */ writerArgs){
                // summary:
                //              Use the given export format type(fileType)
                //              and writer arguments(writerArgs) to create
                //              a ExportWriter and return it.
                // tags:
                //              private
                var writerName, cls,
                        expCls = Exporter;
                if(expCls.writerNames){
                        writerName = expCls.writerNames[fileType.toLowerCase()];
                        cls = lang.getObject(writerName);
                        if(cls){
                                var writer = new cls(writerArgs);
                                writer.formatter = this.formatter;
                                return writer;  //ExportWriter
                        }else{
                                throw new Error('Please make sure class "' + writerName + '" is required.');
                        }
                }
                throw new Error('The writer for "' + fileType + '" has not been registered.');
        }
});

Exporter.registerWriter = function(/* string */fileType,/* string */writerClsName){
        // summary:
        //              Register a writer(writerClsName) to a export format type(fileType).
        //              This function separates the Exporter from all kinds of writers.
        // tags:
        //              public
        Exporter.writerNames = Exporter.writerNames || {};
        Exporter.writerNames[fileType] = writerClsName;
};

EnhancedGrid.registerPlugin(Exporter/*name:'exporter'*/);

return Exporter;
});