model.js

ajax框架原吗,dojo目前很流行的,希望大家多多学习啊

	// paging
	requestsPending: function(inBoolean){
	},
	rowToPage: function(inRowIndex){
		return (this.rowsPerPage ? Math.floor(inRowIndex / this.rowsPerPage) : inRowIndex);
	},
	pageToRow: function(inPageIndex){
		return (this.rowsPerPage ? this.rowsPerPage * inPageIndex : inPageIndex);
	},
	requestRows: function(inRowIndex, inCount){
		// summary:
		//		stub. Fill in to perform actual data row fetching logic. The
		//		returning logic must provide the data back to the system via
		//		setRow
	},
	rowsProvided: function(inRowIndex, inCount){
		this.requests--;
		if(this.requests == 0){
			this.requestsPending(false);
		}
	},
	requestPage: function(inPageIndex){
		var row = this.pageToRow(inPageIndex);
		var count = Math.min(this.rowsPerPage, this.count - row);
		if(count > 0){
			this.requests++;
			this.requestsPending(true);
			setTimeout(dojo.hitch(this, "requestRows", row, count), 1);
			//this.requestRows(row, count);
		}
	},
	needPage: function(inPageIndex){
		if(!this.pages[inPageIndex]){
			this.pages[inPageIndex] = true;
			this.requestPage(inPageIndex);
		}
	},
	preparePage: function(inRowIndex, inColIndex){
		if(inRowIndex < this.bop || inRowIndex >= this.eop){
			var pageIndex = this.rowToPage(inRowIndex);
			this.needPage(pageIndex);
			this.bop = pageIndex * this.rowsPerPage;
			this.eop = this.bop + (this.rowsPerPage || this.count);
		}
	},
	isRowLoaded: function(inRowIndex){
		return Boolean(this.data[inRowIndex]);
	},
	// removal
	removePages: function(inRowIndexes){
		for(var i=0, r; ((r=inRowIndexes[i]) != undefined); i++){
			this.pages[this.rowToPage(r)] = false;
		}
		this.bop = this.eop =-1;
	},
	remove: function(inRowIndexes){
		this.removePages(inRowIndexes);
		dojox.grid.data.Table.prototype.remove.apply(this, arguments);
	},
	// access
	getRow: function(inRowIndex){
		var row = this.data[inRowIndex];
		if(!row){
			this.preparePage(inRowIndex);
		}
		return row;
	},
	getDatum: function(inRowIndex, inColIndex){
		var row = this.getRow(inRowIndex);
		return (row ? row[inColIndex] : this.fields.get(inColIndex).na);
	},
	setDatum: function(inDatum, inRowIndex, inColIndex){
		var row = this.getRow(inRowIndex);
		if(row){
			row[inColIndex] = inDatum;
			this.datumChange(inDatum, inRowIndex, inColIndex);
		}else{
			console.debug('[' + this.declaredClass + '] dojox.grid.data.dynamic.set: cannot set data on an non-loaded row');
		}
	},
	// sort
	canSort: function(){
		return false;
	}
});

// FIXME: deprecated: (included for backward compatibility only)
dojox.grid.data.table = dojox.grid.data.Table;
dojox.grid.data.dynamic = dojox.grid.data.Dyanamic;

// we treat dojo.data stores as dynamic stores because no matter how they got
// here, they should always fill that contract
dojo.declare("dojox.grid.data.DojoData", dojox.grid.data.Dynamic, {
	//	summary:
	//		A grid data model for dynamic data retreived from a store which
	//		implements the dojo.data API set. Retrieves data automatically when
	//		requested and provides notification when data is received
	//	description:
	//		This store subclasses the Dynamic grid data object in order to
	//		provide paginated data access support, notification and view
	//		updates for stores which support those features, and simple
	//		field/column mapping for all dojo.data stores.
	constructor: function(inFields, inData, args){
		this.count = 1;
		this._rowIdentities = {};
		if(args){
			dojo.mixin(this, args);
		}
		if(this.store){
			// NOTE: we assume Read and Identity APIs for all stores!
			var f = this.store.getFeatures();
			this._canNotify = f['dojo.data.api.Notification'];
			this._canWrite = f['dojo.data.api.Write'];

			if(this._canNotify){
				dojo.connect(this.store, "onSet", this, "_storeDatumChange");
			}
		}
	},
	markupFactory: function(args, node){
		return new dojox.grid.data.DojoData(null, null, args);
	},
	query: { name: "*" }, // default, stupid query
	store: null,
	_canNotify: false,
	_canWrite: false,
	_rowIdentities: {},
	clientSort: false,
	// data
	setData: function(inData){
		this.store = inData;
		this.data = [];
		this.allChange();
	},
	setRowCount: function(inCount){
		//console.debug("inCount:", inCount);
		this.count = inCount;
		this.allChange();
	},
	beginReturn: function(inCount){
		if(this.count != inCount){
			// this.setRowCount(0);
			// this.clear();
			// console.debug(this.count, inCount);
			this.setRowCount(inCount);
		}
	},
	_setupFields: function(dataItem){
		// abort if we already have setup fields
		if(this.fields._nameMaps){
			return;
		}
		// set up field/index mappings
		var m = {};
		//console.debug("setting up fields", m);
		var fields = dojo.map(this.store.getAttributes(dataItem),
			function(item, idx){ 
				m[item] = idx;
				m[idx+".idx"] = item;
				// name == display name, key = property name
				return { name: item, key: item };
			},
			this
		);
		this.fields._nameMaps = m;
		// console.debug("new fields:", fields);
		this.fields.set(fields);
		this.notify("FieldsChange");
	},
	_getRowFromItem: function(item){
		// gets us the row object (and row index) of an item
	},
	processRows: function(items, store){
		// console.debug(arguments);
		if(!items){ return; }
		this._setupFields(items[0]);
		dojo.forEach(items, function(item, idx){
			var row = {}; 
			row.__dojo_data_item = item;
			dojo.forEach(this.fields.values, function(a){
				row[a.name] = this.store.getValue(item, a.name)||"";
			}, this);
			// FIXME: where else do we need to keep this in sync?
			this._rowIdentities[this.store.getIdentity(item)] = store.start+idx;
			this.setRow(row, store.start+idx);
		}, this);
		// FIXME: 
		//	Q: scott, steve, how the hell do we actually get this to update
		//		the visible UI for these rows?
		//	A: the goal is that Grid automatically updates to reflect changes
		//		in model. In this case, setRow -> rowChanged -> (observed by) Grid -> modelRowChange -> updateRow
	},
	// request data 
	requestRows: function(inRowIndex, inCount){
		var row  = inRowIndex || 0;
		var params = { 
			start: row,
			count: this.rowsPerPage,
			query: this.query,
			onBegin: dojo.hitch(this, "beginReturn"),
			//	onItem: dojo.hitch(console, "debug"),
			onComplete: dojo.hitch(this, "processRows") // add to deferred?
		}
		// console.debug("requestRows:", row, this.rowsPerPage);
		this.store.fetch(params);
	},
	getDatum: function(inRowIndex, inColIndex){
		//console.debug("getDatum", inRowIndex, inColIndex);
		var row = this.getRow(inRowIndex);
		var field = this.fields.values[inColIndex];
		return row && field ? row[field.name] : field ? field.na : '?';
		//var idx = row && this.fields._nameMaps[inColIndex+".idx"];
		//return (row ? row[idx] : this.fields.get(inColIndex).na);
	},
	setDatum: function(inDatum, inRowIndex, inColIndex){
		var n = this.fields._nameMaps[inColIndex+".idx"];
		// console.debug("setDatum:", "n:"+n, inDatum, inRowIndex, inColIndex);
		if(n){
			this.data[inRowIndex][n] = inDatum;
			this.datumChange(inDatum, inRowIndex, inColIndex);
		}
	},
	// modification, update and store eventing
	copyRow: function(inRowIndex){
		var row = {};
		var backstop = {};
		var src = this.getRow(inRowIndex);
		for(var x in src){
			if(src[x] != backstop[x]){
				row[x] = src[x];
			}
		}
		return row;
	},
	_attrCompare: function(cache, data){
		dojo.forEach(this.fields.values, function(a){
			if(cache[a.name] != data[a.name]){ return false; }
		}, this);
		return true;
	},
	endModifyRow: function(inRowIndex){
		var cache = this.cache[inRowIndex];
		if(cache){
			var data = this.getRow(inRowIndex);
			if(!this._attrCompare(cache, data)){
				this.update(cache, data, inRowIndex);
			}
			delete this.cache[inRowIndex];
		}
	},
	cancelModifyRow: function(inRowIndex){
		// console.debug("cancelModifyRow", arguments);
		var cache = this.cache[inRowIndex];
		if(cache){
			this.setRow(cache, inRowIndex);
			delete this.cache[inRowIndex];
		}
	},
	_storeDatumChange: function(item, attr, oldVal, newVal){
		// the store has changed some data under us, need to update the display
		var rowId = this._rowIdentities[this.store.getIdentity(item)];
		var row = this.getRow(rowId);
		row[attr] = newVal;
		var colId = this.fields._nameMaps[attr];
		this.notify("DatumChange", [ newVal, rowId, colId ]);
	},
	datumChange: function(value, rowIdx, colIdx){
		if(this._canWrite){
			// we're chaning some data, which means we need to write back
			var row = this.getRow(rowIdx);
			var field = this.fields._nameMaps[colIdx+".idx"];
			this.store.setValue(row.__dojo_data_item, field, value);
			// we don't need to call DatumChange, an eventing store will tell
			// us about the row change events
		}else{
			// we can't write back, so just go ahead and change our local copy
			// of the data
			this.notify("DatumChange", arguments);
		}
	},
	insertion: function(/* index */){
		console.debug("Insertion", arguments);
		this.notify("Insertion", arguments);
		this.notify("Change", arguments);
	},
	removal: function(/* keys */){
		console.debug("Removal", arguments);
		this.notify("Removal", arguments);
		this.notify("Change", arguments);
	},
	// sort
	canSort: function(){
		// Q: Return true and re-issue the queries?
		// A: Return true only. Re-issue the query in 'sort'.
		return this.clientSort;
	}
});

}