static/ext/src/form/field/Base.js
function(value) {
        var me = this,
            errors = me.getErrors(value),
            isValid = Ext.isEmpty(errors);
        if (!me.preventMark) {
            if (isValid) {
                me.clearInvalid();
            } else {
                me.markInvalid(errors);
            }
        }

        return isValid;
    }
function(value) {
        var me = this,
            errors = me.getErrors(value),
            isValid = Ext.isEmpty(errors);
        if (!me.preventMark) {
            if (isValid) {
                me.clearInvalid();
            } else {
                me.markInvalid(errors);
            }
        }

        return isValid;
    }
Uses {@link #getErrors} to build an array of validation errors. If any errors are found, they are passed to
{@link #markInvalid} and false is returned, otherwise true is returned.

Previously, subclasses were invited to provide an implementation of this to process validations - from 3.2
onwards {@link #getErrors} should be overridden instead.

@param {Object} value The value to validate
@return {Boolean} True if all validations passed, false if one or more failed