Need help with problem with anonymous ids - ruby-on-rails

Question

i have:
var answers_json = [{
name: "email",
mapping: "answer.respondent.email"
}, {
name: "group",
mapping: "answer.respondent.respondent_group_id"
}, {
name: "text",
mapping: "answer.text"
}, {
name: "scale",
mapping: "answer.scale"
}, {
name: "created_at",
mapping: "answer.created_at",
type: "date",
dateFormat: "c"
}];
var answers_columns = [{
id: "email",
header: a_email,
width: 240,
sortable: true,
resizable: false,
menuDisabled: true,
dataIndex: "email",
//renderer: anonim_fun i need to write function?
}, {
id: "group",
header: "<div style=text-align:center>" + a_group + "</div>",
width: 55,
sortable: true,
resizable: false,
menuDisabled: true,
dataIndex: "group"
}, {
id: "text",
header: a_answer,
width: 550,
sortable: true,
resizable: false,
menuDisabled: true,
dataIndex: "text"
}, {
id: "scale",
header: a_scale,
width: 50,
sortable: true,
resizable: false,
menuDisabled: true,
dataIndex: "scale"
}, {
id: "created_at",
header: a_added_date,
width: 120,
sortable: true,
resizable: false,
menuDisabled: true,
dataIndex: "created_at",
xtype: "datecolumn",
format: "Y-m-d H:i:s"
}];
Problem is follow:
I have tables (as you can see) ..if respondent answered and he putted flag to (I ASK ANONYMOUS) then (IN MY VERSION) respondent_id gets 0 as id and in tale respondents there are user with some id called anonymous and then in extjs i see - anonymous (from respondent_id).
This works, but there are another way.. add field is_anonymous into inquiry table (relation between answers & respondents tables). but answers_json in column email get info about answer.respondent.email... How i can do another way with just adding field is_annonymous (and if yes = 1, if no = 0). this is much clever. But how it write in extJS? Function? AND HOW?
thanks!

Answer 1

You can use convert: as part of your field definition. Look at the current value and replace it with what you prefer.
{
name: "email",
mapping: "answer.respondent.email"
convert: function(val) {
if(val=="....") {
return "(anonymous)"
}
},