lib/src/sync/w3c_spec/element_finder.dart

// Copyright 2017 Google Inc. All Rights Reserved.
//
// Licensed 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 'web_element.dart';

import '../common.dart';
import '../web_driver.dart';
import '../web_element.dart';

/// Handles logic for finding elements in both WebDriver and element contexts.
class ElementFinder {
  final WebDriver _driver;
  final SearchContext _context;
  final Resolver _resolver;

  ElementFinder(this._driver, this._resolver, this._context);

  /// Here we massage [By] instances into viable W3C /element requests.
  ///
  /// In principle, W3C spec implementations should be nearly the same as
  /// the existing JSON wire spec. In practice compliance is uneven.
  Map<String, String> _byToJson(By by) {
    String using;
    String value;

    switch (by.using) {
      case 'id': // This doesn't exist in the W3C spec.
        using = 'css selector';
        value = '#${by.value}';
        break;
      case 'name': // This doesn't exist in the W3C spec.
        using = 'css selector';
        value = '[name=${by.value}]';
        break;
      case 'tag name': // This is in the W3C spec, but not in geckodriver.
        using = 'css selector';
        value = by.value;
        break;
      // xpath, css selector, link text, partial link text, seem fine.
      default:
        using = by.using;
        value = by.value;
    }

    return {'using': using, 'value': value};
  }

  List<WebElement> findElements(By by) {
    final elements =
        _resolver.post('elements', _byToJson(by)).cast<Map<String, dynamic>>();

    // "as List<String>;" should not be necessary, but helps IntelliJ
    final ids = elements.fold(<String>[], (cur, m) {
      cur.addAll(m.values.cast<String>());
      return cur;
    }) as List<String>;

    var i = 0;
    return ids
        .map((id) => new W3cWebElement(_driver, id, _context, by, i++))
        .toList();
  }

  WebElement findElement(By by) {
    final element =
        _resolver.post('element', _byToJson(by)).cast<String, String>();
    return new W3cWebElement(_driver, element.values.first, _context, by);
  }

  WebElement findActiveElement() {
    final element = _resolver.get('element/active');
    if (element != null) {
      return new W3cWebElement(
          _driver, element.values.first, _context, 'activeElement');
    }
    return null;
  }
}