Extjs 4.2: How to send parameters properly in a Ext.Ajax.Request POST

The problem is that you are using the line headers: {'Content-Type': 'text/html'}, in your original question. This would set the content to text/html instead of the content being post data.

I'm using this in a Sencha Touch app. I had to add an extra config called jsonData and make it true or else nothing is passed to my endpoint url.

Ext.Ajax.request({
    url: endpoint,
    method : "POST",
    headers: {
        'Content-Type': 'application/json'
    },
    params : {add: formattedAddress, lat: latitude},
    jsonData: true,
    useDefaultXhrHeader : false,
    withCredentials: true,                
    success : function(response) {
        Ext.Msg.alert("Success", 'yea');
    },
    failure : function(response) {
        var respObj = Ext.JSON.decode(response.responseText);
        Ext.Msg.alert("Error", respObj.status.statusMessage);
    }
});

I solved it with the following code:

var rolename = 'myRol';
Ext.Ajax.request({
    url: 'deleteRole.html',
    method: 'POST',          
    params: {
        rolename: rolename
    },
    success: received,                                    
    failure: function(){console.log('failure');}
});