Ext.data.HttpProxy callback on failure - extjs

Question

I've the following ExtJS. The listener "write" is called when the response is a success (the response is JSON like: {"success":true,"message":"......"}). But how do I attach a callback when the response is not a success? ({"success":false,"message":"......"})
tableStructure.proxy = new Ext.data.HttpProxy({
api: {
read: '/controller/tables/' + screenName + '/getstructure/' + table,
create: '/controller/tables/' + screenName + '/createcolumn/' + table,
update: '/controller/tables/' + screenName + '/updatecolumn/' + table,
destroy: '/controller/tables/' + screenName + '/destroycolumn/' + table
},
listeners: {
write: tableStructure.onWrite
}
});

Answer 1

You want to catch the HttpProxy's exception event.
listeners: {
write: tableStructure.onWrite
exception: function(proxy, type, action, options, response, arg) {
if(type === 'remote') { // success is false
// do your error handling here
console.log( response ); // the response object sent from the server
}
}
}
You can find the full documentation in the Ext docs for Ext.data.HttpProxy down in the events section.

Answer 2

You should be able to make use of the write event itself. The write event's signature is:
write(dataproxy,action,data,response,record,options).
You can access the success variable from the action object and check if the value is true or false. You should be able to access the success variable as:
action.result.success
You can do:
if(action.result.success != true ) {
// If success is not true
} else {
// If success is true
}

Answer 3

You can also set an exception handler on the Ext.data.Store wrapping the HttpProxy, provided that you send a response code other than 200.
var store = new CQ.Ext.data.Store({
proxy : new CQ.Ext.data.HttpProxy({
method : "GET",
url : '/some_url'
}),
reader : new CQ.Ext.data.JsonReader(),
baseParams : {
param : 'some value'
}
});
store.on("beforeload", function() {
CQ.Ext.getBody().mask("Please wait...", false);
});
store.on("exception", function() {
CQ.Ext.getBody().unmask();
CQ.Ext.Msg.show({
title: 'Error',
msg: '<span style="color:red">Bad request.</span><br/>',
icon: CQ.Ext.Msg.ERROR,
buttons: CQ.Ext.Msg.OK
});
});