source: Dev/trunk/src/client/dijit/tests/_data/SlowStore.js

define(["dojo/_base/declare", "dojo/data/ItemFileReadStore"], function(declare, ItemFileReadStore){

        return declare("dijit.tests._data.SlowStore", ItemFileReadStore, {
                // summary:
                //              This wrapper decorates an ItemFileReadStore by delaying queries issued according to the
                //              length of the query:
                //
                //              - empty query: 2000ms,
                //              - 1 or 2 characters: 1000ms,
                //              - 3 characters: 500ms,
                //              - 4 or more characters: 100ms.

                constructor: function(){
                        this.log = [];
                },

                fetch: function(/* Object */ keywordArgs){
                        // Get the query phrase (store into first), and the # of chars it has
                        var count = 0;
                        var first;
                        if("query" in keywordArgs){
                                var query = keywordArgs.query;
                                for(var attr in query){
                                        first = query[attr];
                                        break;
                                }
                                count = first.toString().length;
                        }

                        var delay = 100;
                        switch(count || 0){
                                case 0:
                                        delay = 2000;
                                        break;
                                case 1:
                                case 2:
                                        delay = 1000;
                                        break;
                                case 3:
                                        delay = 500;
                                        break;
                                case 4:
                                        delay = 100;
                                        break;
                        }

                        this.log.push({
                                type: "start",
                                date: new Date(),
                                query: query,
                                count: count,
                                delay: delay
                        });
                        console.log("START query on " + (first || "{}") + " (" + count + " chars), delay = " + delay);

                        var that = this,
                                thatArgs = arguments;
                        var handle = setTimeout(function(){
                                that.log.push({
                                        type: "end",
                                        date: new Date(),
                                        query: query,
                                        count: count,
                                        delay: delay
                                });
                                console.log("END query on " + (first || "{}") + " (" + count + " chars), delay = " + delay);
                                ItemFileReadStore.prototype.fetch.apply(that, thatArgs);
                        }, delay);

                        // This abort() method cancels a request before it has even been sent to ItemFileReadStore.
                        // (Since ItemFileReadStore has already loaded the data (as per code in the test file),
                        // it operates synchronously; there is never a case to send the cancel request to that object)
                        keywordArgs.abort = function(){
                                clearTimeout(handle);
                                that.log.push({
                                        type: "cancel",
                                        date: new Date(),
                                        query: query,
                                        count: count,
                                        delay: delay
                                });
                                console.log("CANCEL query on " + (first || "{}") + " (" + count + " chars), delay = " + delay);
                        };

                        return keywordArgs;
                }
        });

});