ExtJs：等待Store加载完成后再执行下一条语句。

Question

我有一个商店，需要在代码中加载并对记录执行操作。但由于执行是异步的，因此在商店完全加载之前，商店加载后的语句就会被执行。

如何暂停执行直到商店完成加载。

以下是代码：

var fieldsStore = new Ext.create('Ext.data.Store', {
model : 'FieldsModel',
proxy : {
    type : 'ajax',
    url : 'queryBuilder_getQueryDetails',
    extraParams : {
        queryID : queryID
    },
    reader : {
        type : 'json'
    }
},
listeners : {
    load : function(store, records, successful, operation, eOpts) {
        if (successful) {
            records.forEach(function(rec) {
                // default settings: if datatype is INTEGER - SUM
                if (rec.get('fieldType') == 'INTEGER') {
                    rec.set('fieldSettingKey', 'SUM');
                    rec.set('fieldSettingValue', 'Sum');
                } else {
                    // else select ROWHEADER by default
                    rec.set('fieldSettingKey', 'ROWHEADER');
                    rec.set('fieldSettingValue', 'Row Header');
                }

            });

            store.commitChanges();
        }
    }
}
});

function loadPivotDefinition(pivotDef) {
// load query in combo
Ext.getCmp('queryListCombo').select(pivotDef.get('queryID'));
// set params as the query id to fetch fields
fieldsStore.proxy.extraParams.queryID = pivotDef.get('queryID');
// load fields store
fieldsStore.load();

 // THIS IS WHERE I WANT TO CODE TO HALT AND CHECK IF THE STORE HAS COMPLETED LOADING.
// load field data (checked, data binding )
debugger;
pivotDef.get('rowHeaders').forEach(
        function(rowRecord) {
            var storeRecord = fieldsStore.findRecord('fieldName',
                    rowRecord.fieldName, 0, false, true, true);
            storeRecord.set('checked', rowRecord.checked);
            storeRecord.set('fieldSettingKey', rowRecord.fieldSettingKey);
            storeRecord.set('fieldSettingValue',
                    rowRecord.fieldSettingValue);
        });
}

- DarkKnightFan

Answer 1

store.load 可以接受回调函数作为参数：

fieldsStore.load(function() {
    // THIS IS WHERE I WANT TO CODE TO HALT AND CHECK IF THE STORE HAS COMPLETED LOADING.
    // load field data (checked, data binding )
    debugger;
    pivotDef.get('rowHeaders').forEach(/*...*/);
});

当您将回调作为参数传递时，数据加载完成后会立即执行回调函数。

- Molecular Man

Answer 2

在某些操作中，使用以下方式来加载存储：

 Ext.getStore('store').load({
 params:  {
      /* parameters to pass*/
    },
 callback : function(records, operation, success) {
       /* perform operations on the records*/
         console.log(records); 
    }
});

- Dev