update one value in JsonStore

How to update particu开发者_Go百科lar value in Jsone store dynamically? When adding one new record to store, based on new record, update existing records in store

it depends you want to update existing record before adding new records to store or after adding new records to store. for updating after adding new records to store you can do something like:

store.on('add', function(store, newRecordsArray, indexWhereRecordsAdded ){
    /* handle update here */
});
store.loadData( newDataArray, true /* to append data */ );

for updating before adding new records to store just do it before passing data to loadData