webui-aria2/js/libs/dojox/grid/enhanced/plugins/_StoreLayer.js.uncompressed.js
2012-05-01 19:52:07 +08:00

396 lines
12 KiB
JavaScript

//>>built
define("dojox/grid/enhanced/plugins/_StoreLayer", [
"dojo/_base/declare",
"dojo/_base/array",
"dojo/_base/lang",
"dojo/_base/xhr"
], function(declare, array, lang, xhr){
// summary:
// The dojo.data.api.Read API is powerful, but it's difficult to give the store some special commands before
// fetch, so that the store content can be temporarily modified or transformed, and acts as another store. The
// parameter *query* or *queryOptions* in keywordArgs for *fetch* is not enough because:
// 1. users do not have the opportunity to response to the store actions when these options or queries are applied,
// especially when the real store is at server side.
// 2. the store implementation must be changed to support any new options in 'query' or 'queryOptions', so it'll be
// difficult if this implementation is not able to or very hard to be changed, or some new options are required to
// be valid for all stores.
// This *StoreLayer* framework is dedicated to provide a uniform way for configuring an existing store, so that
// it can be easily extended to have special behaviors or act like a totally different store.
// The major approach is to wrap the *fetch* function of store, layer by layer. Every layer treats the incoming
// store.fetch as a 'black box', thus maintaining the independence between layers.
// *fetch* is the most important data retriever in the Read API, almost all other functions are used for a single
// item, and require that this item is already retrieved (by and only by *fetch*). So once we've controlled this
// *fetch* function, we've controlled almost the whole store. This fact simplifies our implementation of StoreLayer.
// example:
// //ns is for namespace, i.e.:dojox.grid.enhanced.plugins
// ns.wrap(ns.wrap(ns.wrap(store, new ns.FilterLayer()), new ns.UniqueLayer()), new ns.TransformLayer());
//
// //every layer has a name, it should be given in the document of this layer.
// //if you don't know it's name, you can get it by: ns.SomeLayer.prototype.name();
// store.layer("filter").filterDef(...);
// store.layer("unique").setUniqueColumns(...);
// store.layer("transform").setScheme(...);
//
// //now use the store as usual...
//
// store.unwrap("transform"); //remove the transform layer but retain the other two.
//
// //now use the store as usual...
//
// store.unwrap(); //remove all the layers, get the original store back.
var ns = lang.getObject("grid.enhanced.plugins", true, dojox);
var getPrevTags = function(tags){
var tagList = ["reorder", "sizeChange", "normal", "presentation"];
var idx = tagList.length;
for(var i = tags.length - 1; i >= 0; --i){
var p = array.indexOf(tagList, tags[i]);
if(p >= 0 && p <= idx){
idx = p;
}
}
if(idx < tagList.length - 1){
return tagList.slice(0, idx + 1);
}else{
return tagList;
}
},
unwrap = function(/* string? */layerName){
// summary:
// Unwrap the layers of the store
// tags:
// public
// returns:
// The unwrapped store, for nested use only.
var i, layers = this._layers, len = layers.length;
if(layerName){
for(i = len-1; i >= 0; --i){
if(layers[i].name() == layerName){
layers[i]._unwrap(layers[i + 1]);
break;
}
}
layers.splice(i, 1);
}else{
for(i = len - 1; i >= 0; --i){
layers[i]._unwrap();
}
}
if(!layers.length){
delete this._layers;
delete this.layer;
delete this.unwrap;
delete this.forEachLayer;
}
//console.log("layers:",this._layers);
return this; //Read-store
},
getLayer = function(layerName){
// summary:
// Get a layer of the store, so we can configure that layer.
// tags:
// public (scope is store)
// layerName: string
// the name of the layer
// returns:
// the store layer object
var i, layers = this._layers;
if(typeof layerName == "undefined"){
return layers.length; //Integer
}
if(typeof layerName == "number"){
return layers[layerName]; //_StoreLayer
}
for(i = layers.length - 1; i >= 0; --i){
if(layers[i].name() == layerName){
return layers[i]; //_StoreLayer
}
}
return null; //_StoreLayer
},
forEachLayer = function(callback, isInnerToOuter){
// summary:
// Visit the layers one by one. From the outer most to inner most by default.
// callback: Function
// The function to callback.
// If return false, break the loop.
// isInnerToOuter: Boolean
// Whether visit from the inner most layer to the outer most layer.
var len = this._layers.length, start, end, dir;
if(isInnerToOuter){
start = 0;
end = len;
dir = 1;
}else{
start = len - 1;
end = -1;
dir = -1;
}
for(var i = start; i != end; i += dir){
if(callback(this._layers[i], i) === false){
return i;
}
}
return end;
};
ns.wrap = function(store, funcName, layer, layerFuncName){
// summary:
// Wrap the store with the given layer.
// tags:
// public
// store: Read-store
// The store to be wrapped.
// layer: _StoreLayer
// The layer to be used
// returns
// The wrapped store, for nested use only.
if(!store._layers){
store._layers = [];
store.layer = lang.hitch(store, getLayer);
store.unwrap = lang.hitch(store, unwrap);
store.forEachLayer = lang.hitch(store, forEachLayer);
}
var prevTags = getPrevTags(layer.tags);
if(!array.some(store._layers, function(lyr, i){
if(array.some(lyr.tags, function(tag){
return array.indexOf(prevTags, tag) >= 0;
})){
return false;
}else{
store._layers.splice(i, 0, layer);
layer._wrap(store, funcName, layerFuncName, lyr);
return true;
}
})){
store._layers.push(layer);
layer._wrap(store, funcName, layerFuncName);
}
//console.log("wrapped layers:", dojo.map(store._layers, function(lyr){return lyr.name();}));
return store; //Read-store
};
var _StoreLayer = declare("dojox.grid.enhanced.plugins._StoreLayer", null, {
// summary:
// The most abstract class of store layers, provides basic utilities and some interfaces.
// tags:
// abstract
/*=====
// _store: [protected] Read-store
// The wrapped store.
_store: null,
// _originFetch: [protected] function
// The original fetch function of the store.
_originFetch: null,
// __enabled: [private] Boolean
// To control whether this layer is valid.
__enabled: true,
=====*/
tags: ["normal"],
layerFuncName: "_fetch",
constructor: function(){
this._store = null;
this._originFetch = null;
this.__enabled = true;
},
initialize: function(store){
// summary:
//
},
uninitialize: function(store){
// summary:
//
},
invalidate: function(){
},
_wrap: function(store, funcName, layerFuncName, nextLayer){
// summary:
// Do the actual wrapping (or 'hacking' if you like) to the store.
// tags:
// internal
// store: Read-store
// The store to be wrapped.
this._store = store;
this._funcName = funcName;
var fetchFunc = lang.hitch(this, function(){
return (this.enabled() ? this[layerFuncName || this.layerFuncName] : this.originFetch).apply(this, arguments);
});
if(nextLayer){
this._originFetch = nextLayer._originFetch;
nextLayer._originFetch = fetchFunc;
}else{
this._originFetch = store[funcName] || function(){};
store[funcName] = fetchFunc;
}
this.initialize(store);
},
_unwrap: function(nextLayer){
// summary:
// Do the actual unwrapping to the store.
// tags:
// internal
// store: Read-store
// The store to be unwrapped.
this.uninitialize(this._store);
if(nextLayer){
nextLayer._originFetch = this._originFetch;
}else{
this._store[this._funcName] = this._originFetch;
}
this._originFetch = null;
this._store = null;
},
enabled: function(/* bool? */toEnable){
// summary:
// The get/set function of the enabled status of this layer
// tags:
// public
// toEnable: Boolean?
// If given, is a setter, otherwise, it's getter.
if(typeof toEnable != "undefined"){
this.__enabled = !!toEnable;
}
return this.__enabled; //Boolean
},
name: function(){
// summary:
// Get the name of this store layer.
// The default name retrieved from class name, which should have a pattern of "{name}Layer".
// If this pattern does not exist, the whole class name will be this layer's name.
// It's better to override this method if your class name is too complicated.
// tags:
// public extension
// returns:
// The name of this layer.
if(!this.__name){
var m = this.declaredClass.match(/(?:\.(?:_*)([^\.]+)Layer$)|(?:\.([^\.]+)$)/i);
this.__name = m ? (m[1] || m[2]).toLowerCase() : this.declaredClass;
}
return this.__name;
},
originFetch: function(){
return (lang.hitch(this._store, this._originFetch)).apply(this, arguments);
}
});
var _ServerSideLayer = declare("dojox.grid.enhanced.plugins._ServerSideLayer", _StoreLayer, {
// summary:
// The most abstract class for all server side store layers.
// tags:
// abstract
/*=====
// _url: [protected] string
// The url of the server
_url: "",
// __cmds [private] object
// The command object to be sent to server.
__cmds: {},
=====*/
constructor: function(args){
args = args || {};
this._url = args.url || "";
this._isStateful = !!args.isStateful;
this._onUserCommandLoad = args.onCommandLoad || function(){};
this.__cmds = {cmdlayer:this.name(), enable:true};
//Only for stateful server, sending commands before fetch makes sense.
this.useCommands(this._isStateful);
},
enabled: function(/* bool? */toEnable){
// summary:
// Overrided from _StoreLayer.enabled
var res = this.inherited(arguments);
this.__cmds.enable = this.__enabled;
return res;
},
useCommands: function(/* bool? */toUse){
// summary:
// If you only want to modify the user request, instead of sending a separate command
// to server before fetch, just call:
// this.useCommand(false);
// tags:
// public
// toUse: Boolean?
// If provided, it's a setter, otherwise, it's a getter
if(typeof toUse != "undefined"){
this.__cmds.cmdlayer = (toUse && this._isStateful) ? this.name() : null;
}
return !!(this.__cmds.cmdlayer); //Boolean
},
_fetch: function(/* keywordArgs */userRequest){
// summary:
// Implementation of _StoreLayer._fetch
if(this.__cmds.cmdlayer){
//We're gonna send command to server before fetch.
xhr.post({
url: this._url || this._store.url,
content: this.__cmds,
load: lang.hitch(this, function(responce){
this.onCommandLoad(responce, userRequest);
this.originFetch(userRequest);
}),
error: lang.hitch(this, this.onCommandError)
});
}else{
//The user only wants to modify the request object.
this.onCommandLoad("", userRequest);
this.originFetch(userRequest);
}
return userRequest; //dojo.data.api.Request
},
command: function(/* string */cmdName,/* (string|number|bool|...)? */cmdContent){
// summary:
// get/set a command (a name-value pair)
// tags:
// public
// cmdName: string
// The name of the command
// cmdContent: anything
// The content of the command
// returns:
// The content of the command if cmdContent is undefined
var cmds = this.__cmds;
if(cmdContent === null){
delete cmds[cmdName];
}else if(typeof cmdContent !== "undefined"){
cmds[cmdName] = cmdContent;
}
return cmds[cmdName]; //anything
},
onCommandLoad: function(/* string */response, /* keywordArgs */userRequest){
// summary:
// When the server gives back *response* for the commands, you can do something here.
// tags:
// callback extension
// response: string
// server response
// userRequest: [in|out] dojo.data.api.Request
// The request object for *fetch*. You can modify this object according to the *response*
// so as to change the behavior of *fetch*
this._onUserCommandLoad(this.__cmds, userRequest, response);
},
onCommandError: function(error){
// summary:
// handle errors when sending commands.
// tags:
// callback extension
// error: Error
console.log(error);
throw error;
}
});
return {
_StoreLayer: _StoreLayer,
_ServerSideLayer: _ServerSideLayer,
wrap: ns.wrap
};
});