decoupled validation and cross-field validation

Decoupled Validation and Cross-Field Validation

   DEMO shows:
   - Validator objects
       Validation is decoupled from Ext.form.Field.
       The decoupled validators in this example are used in three ways:
         1. field editor validation
         2. cell validation from column renderer
         3. external validation from the validate grid button
   - Cross-field validation
       The validator is always provided with the record so that it can
       be used in validating the field.
       In this example:
         1. Col0 and Col1 must either both be set or both be empty.
         2. Col3 must be greater than Col2