ExtJS: Show a loading mask during Ajax calls

This is my first ExtJS post in a long while and sorry it’s not related to ExtJS4; maybe in the near future.Recently I was asked to implement a page wide mask during Ajax calls to prevent user from interfering with the current call by clicking on the screen or doing something they otherwise should not be doing while the call is running. I initially used the “wait:true” option of the Ext.MessageBox configuration, but the stakeholders did not like it since the progress bar it displayed was not synced to the actual length of the call. This is how I ended up implementing it:

function showLoadingMask(loadingMessage)
if (Ext.isEmpty(loadingMessage))
loadText = 'Loading... Please wait';
//Use the mask function on the Ext.getBody() element to mask the body element during Ajax calls
Ext.Ajax.on('beforerequest',function(){Ext.getBody().mask(loadText, 'loading') }, Ext.getBody());
Ext.Ajax.on('requestcomplete',Ext.getBody().unmask ,Ext.getBody());
Ext.Ajax.on('requestexception', Ext.getBody().unmask , Ext.getBody());

Hope it helps!


The meat of the functionality is in binding the mask() and unmask() function of the Ext.Element object to the ‘beforerequest’, ‘requestcomplete’ and ‘requestexception’ events of the Ext.Ajax object. I need a custom message to be displayed depending on the context that’s the reason why i encapsulated that logic in a function. I also tweaked my CSS a little to customize the mask style, overriding the ExtJS style, as well as the style of the message displayed to the user:


.ext-el-mask-msg div {
background-color: #EEEEEE;
border-color: #A3BAD9;
color: #222222;
font: 1.2em tahoma,arial,helvetica,sans-serif;

.ext-el-mask-msg {

padding: 10px;