gethue/ko/extenders/ko.maxLength.js

Hue is an Open source SQL Query Editor for Databases/Warehouses

// Licensed to Cloudera, Inc. under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  Cloudera, Inc. licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import * as ko from 'knockout';

ko.extenders.maxLength = function (target, maxLength) {
  const result = ko
    .computed({
      read: target,
      write: function (val) {
        let newVal = val;
        if (maxLength > 0 && val.length > maxLength) {
          const limitedVal = val.substring(0, maxLength);
          if (target() === limitedVal) {
            target.notifySubscribers();
          } else {
            newVal = limitedVal;
          }
        }
        target(newVal);
      }
    })
    .extend({ notify: 'always' });
  result(target());
  return result;
};