Method getStyleByData

src/openlayers/overlay/Label.js:327–368

* @function Label.prototype.getStyleByData * @description 根据用户数据（feature）设置专题要素的风格。 * @param {FeatureVector} feat - 矢量要素对象。 * @returns {Array. } 专题要素的风格。

(feat)

     * @returns {Array.<ThemeStyle>} 专题要素的风格。
     */
    getStyleByData(feat) {
        var feature = feat;
        feature.style = CommonUtil.copyAttributes(feature.style, this.defaultStyle);
        //将style赋给标签
        if (this.style && this.style.fontSize && parseFloat(this.style.fontSize) < 12) {
            this.style.fontSize = "12px";
        }
        feature.style = CommonUtil.copyAttributes(feature.style, this.style);

        if (this.themeField && this.styleGroups && feature.attributes) {
            var Sf = this.themeField;
            var attributes = feature.attributes;
            var groups = this.styleGroups;
            var isSfInAttrs = false; //指定的 groupField 是否是geotext的属性字段之一
            var attr = null; //属性值

            for (var property in attributes) {
                if (Sf === property) {
                    isSfInAttrs = true;
                    attr = attributes[property];
                    break;
                }
            }

            //判断属性值是否属于styleGroups的某一个范围，以便对标签分组
            if (isSfInAttrs) {
                for (var i = 0, len = groups.length; i < len; i++) {
                    if ((attr >= groups[i].start) && (attr < groups[i].end)) {
                        var sty1 = groups[i].style;
                        if (sty1 && sty1.fontSize && parseFloat(sty1.fontSize) < 12) {
                            sty1.fontSize = "12px";
                        }
                        feature.style = CommonUtil.copyAttributes(feature.style, sty1);
                    }
                }
            }
            feature.style.label = feature.attributes[this.themeField]
        }


        return feature.style;
    }

    /**
     * @function Label.prototype.setLabelsStyle