- Author:
- David Nickerson <nickerso@users.sourceforge.net>
- Date:
- 2009-07-16 02:00:03+12:00
- Desc:
- the starting point for the HH tutorial example
- Permanent Source URI:
- https://models.fieldml.org/workspace/a1/rawfile/f6a8f90307388eb4b040ee3566b84d88b59247f7/dojo-presentation/js/dojo/dojox/data/SnapLogicStore.js
dojo.provide("dojox.data.SnapLogicStore");
dojo.require("dojo.io.script");
dojo.require("dojo.data.util.sorter");
dojo.declare("dojox.data.SnapLogicStore", null, {
Parts: {
DATA: "data",
COUNT: "count"
},
url: "",
constructor: function(/* Object */args){
// summary:
// Initialize a SnapLogicStore object.
// args:
// An object that contains properties for initializing the new data store object. The
// following properties are understood:
// url:
// A URL to the SnapLogic pipeline's output routed through PipeToHttp. Typically, this
// will look like "http://<server-host>:<port>/pipe/<pipeline-url>/<pipeline-output-view>".
// parameters:
// An object whose properties define parameters to the pipeline. The values of these
// properties will be sent to the pipeline as parameters when it run.
//
if(args.url){
this.url = args.url;
}
this._parameters = args.parameters;
},
_assertIsItem: function(/* item */item){
// summary:
// This function tests whether the item passed in is indeed an item in the store.
// item:
// The item to test for being contained by the store.
if(!this.isItem(item)){
throw new Error("dojox.data.SnapLogicStore: a function was passed an item argument that was not an item");
}
},
_assertIsAttribute: function(/* attribute-name-string */ attribute){
// summary:
// This function tests whether the item passed in is indeed a valid 'attribute' like type for the store.
// attribute:
// The attribute to test for being contained by the store.
if(typeof attribute !== "string"){
throw new Error("dojox.data.SnapLogicStore: a function was passed an attribute argument that was not an attribute name string");
}
},
getFeatures: function(){
// summary:
// See dojo.data.api.Read.getFeatures()
return {
'dojo.data.api.Read': true
};
},
getValue: function(item, attribute, defaultValue){
// summary:
// See dojo.data.api.Read.getValue()
this._assertIsItem(item);
this._assertIsAttribute(attribute);
var i = dojo.indexOf(item.attributes, attribute);
if(i !== -1){
return item.values[i];
}
return defaultValue;
},
getAttributes: function(item){
// summary:
// See dojo.data.api.Read.getAttributes()
this._assertIsItem(item);
return item.attributes;
},
hasAttribute: function(item, attribute){
// summary:
// See dojo.data.api.Read.hasAttributes()
this._assertIsItem(item);
this._assertIsAttribute(attribute);
for(var i = 0; i < item.attributes.length; ++i){
if(attribute == item.attributes[i]){
return true;
}
}
return false;
},
isItemLoaded: function(item){
// summary:
// See dojo.data.api.Read.isItemLoaded()
return this.isItem(item); // Boolean
},
loadItem: function(keywordArgs){
// summary:
// See dojo.data.api.Read.loadItem()
},
getLabel: function(item){
// summary:
// See dojo.data.api.Read.getLabel()
return undefined;
},
getLabelAttributes: function(item){
// summary:
// See dojo.data.api.Read.getLabelAttributes()
return null;
},
containsValue: function(item, attribute, value){
// summary:
// See dojo.data.api.Read.containsValue()
return this.getValue(item, attribute) === value; // Boolean
},
getValues: function(item, attribute){
// summary:
// See dojo.data.api.Read.getValue()
this._assertIsItem(item);
this._assertIsAttribute(attribute);
var i = dojo.indexOf(item.attributes, attribute);
if(i !== -1){
return [item.values[i]]; // Array
}
return [];
},
isItem: function(item){
// summary:
// See dojo.data.api.Read.isItem()
if(item && item._store === this){
return true;
}
return false;
},
close: function(request){
// summary:
// See dojo.data.api.Read.close()
},
_fetchHandler: function(/* Object */request){
// summary:
// Process data retrieved via fetch and send it back to requester.
// response:
// The data returend from the I/O transport. In the normal case, it will be an array of result rows
// from the pipeline. In the special case for record count optimization, response will be an array
// with a single element containing the total pipeline result row count. See fetch() for details
// on this optimization.
var scope = request.scope || dojo.global;
if(request.onBegin){
// Check for the record count optimization
request.onBegin.call(scope, request._countResponse[0], request);
}
if(request.onItem || request.onComplete){
var response = request._dataResponse;
if (!response.length){
request.onError.call(scope,
new Error("dojox.data.SnapLogicStore: invalid response of length 0"),
request);
return;
}else if(request.query != 'record count'){
//If this was not a record count request, the first element returned will contain
//the field names.
var field_names = response.shift();
var items = [];
for(var i = 0; i < response.length; ++i){
if(request._aborted){
break;
}
items.push({attributes: field_names, values: response[i], _store: this});
}
if(request.sort && !request._aborted){
items.sort(dojo.data.util.sorter.createSortFunction(request.sort, self));
}
}else{
//This is a record count request, so manually set the field names.
items = [({attributes: ['count'], values: response, _store: this})];
}
if(request.onItem){
for(var i = 0; i < items.length; ++i){
if (request._aborted) {
break;
}
request.onItem.call(scope, items[i], request);
}
items = null;
}
if(request.onComplete && !request._aborted){
request.onComplete.call(scope, items, request);
}
}
},
_partHandler: function(/* Object */request, /* String */part, /* Object */response){
// summary:
// Handle the individual replies for both data and length requests.
// request:
// The request/handle object used with the original fetch() call.
// part:
// A value indicating which request this handler call is for (this.Parts).
// response:
// Response received from the underlying IO transport.
if(response instanceof Error){
if(part == this.Parts.DATA){
request._dataHandle = null;
}else{
request._countHandle = null;
}
request._aborted = true;
if(request.onError){
request.onError.call(request.scope, response, request);
}
}else{
if(request._aborted){
return;
}
if(part == this.Parts.DATA){
request._dataResponse = response;
}else{
request._countResponse = response;
}
if((!request._dataHandle || request._dataResponse !== null) &&
(!request._countHandle || request._countResponse !== null)){
this._fetchHandler(request);
}
}
},
fetch: function(/* Object */request){
// summary:
// See dojo.data.api.Read.close()
// request:
// See dojo.data.api.Read.close() for generic interface.
//
// In addition to the standard Read API fetch support, this store supports an optimization for
// for retrieving the total count of records in the Pipeline without retrieving the data. To
// use this optimization, simply provide an onBegin handler without an onItem or onComplete handler.
request._countResponse = null;
request._dataResponse = null;
request._aborted = false;
request.abort = function(){
if(!request._aborted){
request._aborted = true;
if(request._dataHandle && request._dataHandle.cancel){
request._dataHandle.cancel();
}
if(request._countHandle && request._countHandle.cancel){
request._countHandle.cancel();
}
}
};
// Only make the call for data if onItem or onComplete is used. Otherwise, onBegin will only
// require the total row count.
if(request.onItem || request.onComplete){
var content = this._parameters || {};
if(request.start){
if(request.start < 0){
throw new Error("dojox.data.SnapLogicStore: request start value must be 0 or greater");
}
content['sn.start'] = request.start + 1;
}
if(request.count){
if(request.count < 0){
throw new Error("dojox.data.SnapLogicStore: request count value 0 or greater");
}
content['sn.limit'] = request.count;
}
content['sn.content_type'] = 'application/javascript';
var store = this;
var handler = function(response, ioArgs){
if(response instanceof Error){
store._fetchHandler(response, request);
}
};
var getArgs = {
url: this.url,
content: content,
// preventCache: true,
timeout: 60000, //Starting a pipeline can take a long time.
callbackParamName: "sn.stream_header",
handle: dojo.hitch(this, "_partHandler", request, this.Parts.DATA)
};
request._dataHandle = dojo.io.script.get(getArgs);
}
if(request.onBegin){
var content = {};
content['sn.count'] = 'records';
content['sn.content_type'] = 'application/javascript';
var getArgs = {
url: this.url,
content: content,
timeout: 60000,
callbackParamName: "sn.stream_header",
handle: dojo.hitch(this, "_partHandler", request, this.Parts.COUNT)
};
request._countHandle = dojo.io.script.get(getArgs);
}
return request; // Object
}
});
