Question

I have a combo-box with following configuration.

{
    fieldLabel:'Service',
    xtype:'combo',
    displayField: 'srvcDesc',
    store: storeServiceCodeVar,
    valueField:'srvcCD',
    id:'serviceCodeId',
    name:'serviceCodeName',
    queryMode: 'remote',
    queryDelay:100,
    typeAhead: true,
    minChars:0,
    hideTrigger:true,
    forceSelection:true,
    maxHeight:23,
    deferEmptyText:false,
    autoSelect:true,
    fieldStyle:'text-transform:uppercase',
    listConfig: {
        loadingText: 'Loading...',
        // Custom rendering template for each item
        getInnerTpl: function() {
            return '<table width="200px"><tr><td height="5"></td></tr><tr valign="top"><td>Code:{srvcCD}</td></tr><tr><td height="2"></td></tr><tr valign="top"><td>Description:{srvcDesc}</td></tr><tr><td height="5"></td></tr></table>';
        },
        emptyText:'No Values Found'
    }
}

The issue is that when there is no data returned from the server, then emptyText (which has value – No values found) gets displayed for may be a millisecond and goes off. I want it to stay there till the next query if fired. How is it possible. I have tried with deferEmptyText but no luck.

Could someone throw some light on this. I am using ExtJS 4 and behavior is same in IE9 and Mozilla.

Thanks in advance.

Answer 1

From stepping through the source, it doesn’t seem like there is any reference to the listConfig.emptyText being used to determine whether or not to set the element’s height to a number other than zero.

I’ve ended up overriding the alignPicker() function which Ext.form.field.ComboBox inherits from Ext.form.field.Picker, and adding a check for listConfig.emptyText.

Ext.override(Ext.form.field.ComboBox, {

    alignPicker: function() {
        var picker, height;

        if (this.isExpanded) {
            // Get the picker component.
            picker = this.getPicker();

            if (this.matchFieldWidth) {
                // Set the default height to null, since we don't 
                // automatically want to have the height changed.
                height = null;

                // If our store exists, but the count is zero
                // and we've got no emptyText defined...
                if (picker.store && 
                    picker.store.getCount() === 0 && 
                    Ext.isEmpty(this.listConfig.emptyText)) {
                    // ...we set the height to zero. 
                    height = 0;
                }

                // Set the size of the picker component.
                picker.setSize(this.bodyEl.getWidth(), height);
            }

            if (picker.isFloating()) {
                this.doAlign();
            }
        }
    }

});

Hope this helps!