Method createDataflowLayer

src/openlayers/mapping/WebMap.js:3872–3954

* @private * @function WebMap.prototype.createDataflowLayer * @description 创建数据流图层 * @param {Object} layerInfo- 图层信息 * @param {number} layerIndex - 图层的zindex * @returns {ol.layer.Vector} 数据流图层

(layerInfo, layerIndex)

   * @returns {ol.layer.Vector} 数据流图层
   */
  async createDataflowLayer(layerInfo, layerIndex) {
    let layerStyle = layerInfo.pointStyle,
      style;
    //获取样式
    style = await StyleUtils.getOpenlayersStyle(layerStyle, layerInfo.featureType);

    let source = new Vector({
        wrapX: false
      }),
      labelLayer,
      labelSource,
      pathLayer,
      pathSource;
    let layer = new olLayer.Vector({
      styleOL: style,
      source: source
    });
    if (layerInfo.labelStyle && layerInfo.visible) {
      //有标签图层
      labelLayer = this.addLabelLayer(layerInfo);
      //和编辑页面保持一致
      labelLayer.setZIndex(1000);
      labelSource = labelLayer.getSource();
    }
    const { visibleScale } = layerInfo;
    if (layerInfo.lineStyle && layerInfo.visible) {
      pathLayer = await this.createVectorLayer({ style: layerInfo.lineStyle, featureType: 'LINE' });
      pathSource = pathLayer.getSource();
      pathLayer.setZIndex(layerIndex);
      this.map.addLayer(pathLayer);
      visibleScale && this.setVisibleScales(pathLayer, visibleScale);
      // 挂载到layerInfo上，便于删除
      layerInfo.pathLayer = pathLayer;
    }
    let featureCache = {},
      labelFeatureCache = {},
      pathFeatureCache = {},
      that = this;
    this.createDataflowService(
      layerInfo,
      (function (featureCache, labelFeatureCache, pathFeatureCache) {
        return function (feature) {
          that.events.triggerEvent('updateDataflowFeature', {
            feature: feature,
            identifyField: layerInfo.identifyField,
            layerID: layerInfo.layerID
          });
          if (layerInfo.filterCondition) {
            //过滤条件
            const condition = that.parseFilterCondition(layerInfo.filterCondition);
            const properties = feature.get('attributes');
            const conditions = parseCondition(condition, Object.keys(properties));
            const filterFeature = parseConditionFeature(properties);
            const sql = 'select * from json where (' + conditions + ')';
            let filterResult = window.jsonsql.query(sql, { attributes: filterFeature });
            if (filterResult && filterResult.length > 0) {
              that.addDataflowFeature(feature, layerInfo.identifyField, {
                dataflowSource: source,