Yii2使用dropdownlist实现地区三级联动功能的方法

<?php
use yii\helpers\url;
use yii\widgets\activeform;
use yii\helpers\arrayhelper;
use yii\helpers\html;
/* @var $this yii\web\view */
/* @var $model common\search\service\itemsearch */
/* @var $form yii\widgets\activeform */
?>
<div class="row">
  <div class="item-search">
    <?php $form = activeform::begin([
      'action' => ['index'],
      'method' => 'get',
      'options' => ['class' => 'form-inline']
    ]); ?>
    <?= $form->field($model, 'cityname', ['options' => ['class' => 'form-group col-lg-2']])->dropdownlist(arrayhelper::map($cities, 'id', 'name'), ['prompt' => '请选择城市'])->label('请选择城市', ['class' => 'sr-only']) ?>
    <?= $form->field($model, 'areaname', ['options' => ['class' => 'form-group col-lg-2']])->dropdownlist(arrayhelper::map($areas, 'id', 'name'), ['prompt' => '请选择区县'])->label('请选择区县', ['class' => 'sr-only']) ?>
    <?= $form->field($model, 'communityname', ['options' => ['class' => 'form-group col-lg-2']])->dropdownlist(arrayhelper::map($communities, 'id', 'name'), ['prompt' => '请选择小区'])->label('请选择小区', ['class' => 'sr-only']) ?>
    <div class="col-lg-2 col-lg-offset-1">
      <input class="form-control" id="keyword" placeholder="请输入小区名" value="" />
    </div>
    <div class="col-lg-1">
      <button type="button" id="search-community" class="btn btn-info">搜索</button>
    </div>
    <p></p>
    <div class="form-group col-lg-1 pull-right">
      <?= html::submitbutton('搜索', ['class' => 'btn btn-primary']) ?>
    </div>
    <?php activeform::end(); ?>
  </div>
</div>
<p> </p>
<?php
$this->registerjs('
  //市地址改变
  $("#itemsearch-cityname").change(function() {
    //市id值
    var cityid = $(this).val();
    $("#itemsearch-areaname").html("<option value=\"0\">请选择区县</option>");
    $("#itemsearch-communityname").html("<option value=\"0\">请选择小区</option>");
    if (cityid > 0) {
      getarea(cityid);
    }
  });
  //区地址改变
  $("#itemsearch-areaname").change(function() {
    //区id值
    var areaid = $(this).val();
    $("#itemsearch-communityname").html("<option value=\"0\">请选择小区</option>");
    if (areaid > 0) {
      getcommunity(areaid);
    }
  });
  //获取市下面的区列表
  function getarea(id)
  {
    var href = "' . url::to(['/service/base/get-area-list'], true). '";
    $.ajax({
      "type" : "get",
      "url"  : href,
      "data" : {id : id},
      success : function(d) {
        $("#itemsearch-areaname").append(d);
      }
    });
  }
  //获取区下面的小区列表
  function getcommunity(id)
  {
    var href = "' . url::to(['/service/base/get-community-list'], true) . '";
    $.ajax({
      "type" : "get",
      "url"  : href,
      "data" : {id : id},
      success : function(d) {
        $("#itemsearch-communityname").append(d);
      }
    });
  }
  //搜索小区
  $("#search-community").click(function() {
    var word  = $("#keyword").val();
    var areaid = $("#itemsearch-areaname option:selected").val();
    var href  = "' . url::to(['/service/base/search-community'], true) . '";
    if (areaid > 0) {
      $.ajax({
        "type" : "get",
        "url"  : href,
        "data" : {id : areaid, word : word},
        success : function(d) {
          $("#itemsearch-communityname").html(d);
        }
      });
    }
  });
');
?>

class huangyeerror extends \yii\db\activerecord
{
  public $cityname;
  public $areaname;
  public $communityname;
  public $group;
  public $cate;
  /**
   * @inheritdoc
   */
  public static function tablename()
  {
    return 'll_hy_huangye_error';
  }
  public static function getdb()
  {
    return yii::$app->get('dbnhuangye');
  }
}

class huangyeerrorsearch extends huangyeerror
{
  const page_size = 20;
  public $communityname;
  public $starttime;
  public $endtime;
  /**
   * @inheritdoc
   */
  public function rules()
  {
    return [
      [['id', 'serviceid', 'userid', 'categoryid', 'communityid', 'sortorder', 'ctime', 'utime', 'status'], 'integer'],
      [['username', 'name', 'logo', 'phone', 'address', 'content', 'error', 'communityname', 'starttime', 'endtime'], 'safe'],
    ];
  }
  /**
   * @inheritdoc
   */
  public function scenarios()
  {
    // bypass scenarios() implementation in the parent class
    return model::scenarios();
  }
  /**
   * creates data provider instance with search query applied
   *
   * @param array $params
   *
   * @return activedataprovider
   */
  public function search($params)
  {
    $query = huangyeerror::find();
    //status == 9 删除状态
    $condition = ' `status` != :status';
    $p[':status'] = 9;
    $query->where($condition, $p);
    $dataprovider = new activedataprovider([
      'query' => $query,
      'pagination' => [
        'pagesize' => self::page_size,
      ],
    ]);
    $this->load($params);
    if (!$this->validate()) {
      // uncomment the following line if you do not want to any records when validation fails
      // $query->where('0=1');
      return $dataprovider;
    }
    $query->andfilterwhere([
      'userid' => $this->userid
    ]);
    $query->andfilterwhere(['like', 'username', $this->username])
      ->andfilterwhere(['like', 'name', $this->name])
      ->andfilterwhere(['like', 'phone', $this->phone])
      ->andfilterwhere(['like', 'address', $this->address])
      ->andfilterwhere(['like', 'content', $this->content])
      ->andfilterwhere(['ll_hy_huangye_error.status' => $this->status])
      ->andfilterwhere(['ll_hy_huangye_error.categoryid' => $this->categoryid])
      ->andfilterwhere(['between', 'ctime', strtotime($this->starttime . '0:0:0'), strtotime($this->endtime . '23:59:59')])
      ->andfilterwhere(['like', 'error', $this->error]);
    if (intval($this->communityname)) {
      $query->andfilterwhere(['ll_hy_huangye_error.communityid' => intval($this->communityname)]);
    }
    $order = ' `ctime` desc';
    $query->orderby($order);
    return $dataprovider;
  }
}

/**
* ajax请求小区
*
* @param $id
* @return string
*/
public function actiongetcommunitylist($id)
{
    $option = '';
    $result = self::getcommunity($id);
    if ($result) {
      foreach ($result as $value) {
        $option .= '<option value="' . $value['id'] . '">' . $value['name'] . '</option>';
      }
    } else {
      $option .= '<option value="0">暂未开通可选择的小区</option>';
    }
    echo $option;
}