checkbox in jqgrid using angular js

The given piece of code is the config.service.js file

       {
        displayName: 'OBS Dt',
        name: 'obsoleteDate',
        index: 'obsoleteDate',
        title:'Obsolete Date',
        width: 100,
        align: "left",
        edittype:"text",
        search : true,
        editable: true
       },



      {
        displayName: 'O',
        name: 'obsoleteFlag',
        index: 'obsoleteFlag',
        title:'Obsolete Flag',
        width: 60,
        align: "center",
        editable: true,
        edittype:"checkbox",
        formatter: 'checkbox',
        formatoptions : {disabled:false},
        toggleCheckboxRule : toggleCheckboxRule,
        editoptions: { value:"Y:N"},
        searchoptions: { sopt: ['eq'], value:":No;Y:Yes" },
        stype: 'select'
       },

Here 'O' is the checkbox while clicking the checkbox some data has to be insert in 'OBS Dt'.I had tried it using below code

  if(column === 'obsoleteFlag'){
     updated.obsoleteFlag = vm.getFlag(extra.currentValue);
          if(extra.currentValue === true) {
          var dateFieldValue= new Date();
          var year = dateFieldValue.getFullYear()+"";
          var month = (dateFieldValue.getMonth()+1)+"";
          var day = dateFieldValue.getDate()+"";
          var dateFormat = month + "/" + day + "/" + year;
          updated.obsoleteDate = dateFormat;
          var retObj = {
            updatedRow: updated,
            column: column
          }  
          console.log(updated);       
        }
        else {
           console.log(extra.currentValue);
           updated.obsoleteFlag = vm.getFlag(extra.currentValue);
           updated.obsoleteDate = null;
        }
        return retObj;
    }

The value gets insert but the 'OBS Dt' must be an editable field in case if the 'OBS Dt' is non-editable, the value doesn't get insert.

But I want by clicking a chekbox the value has to be insert in a non-editable 'OBS Dt' field.

so please help me thanks in advance.