利用Arcgis for javascript API绘制GeoJSON并同时弹出多个Popup

1.引言

  由于Arcgis for javascript API不可以绘制Geojson,并且提供的Popup一般只可以弹出一个,在很多专题图制作中,会遇到不少的麻烦。因此本文结合了两个现有的Arcgis for javascript API扩充库,对其进行改造达到绘制Geojson并同时弹出多个Popup的目的。

目前已有的两个扩充库github地址(可供单独使用):

1.绘制Geojson的扩充库:https://github.com/Esri/geojson-layer-js

2.多个Popup显示的扩充库:https://github.com/nickcam/PopupExtended

  本文实现的效果图:

 

                  图1 上海5个地点的部分预报属性                                 图2 上海某三条航线的部分预报属性

2. 各类依赖库引入及前端HTML

  首先需要先载入需要用的常用js、Arcgis及两个扩充库的js及部分css(下载地址见其github):

<!DOCTYPE html>
<html>
<head>
    <title>Add GeoJSON and Display Multiple Popup</title>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=7,IE=9">
    <meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no">

    <!-- ArcGIS API for JavaScript CSS-->
    <link rel="stylesheet" href="http://js.arcgis.com/3.13/esri/css/esri.css">
    <link rel="stylesheet" href="http://js.arcgis.com/3.13/dijit/themes/claro/claro.css">
    <!-- Web Framework CSS - Bootstrap (getbootstrap.com) and Bootstrap-map-js (github.com/esri/bootstrap-map-js) -->
    <link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css" rel="stylesheet">
    <link rel="stylesheet" href="./css/bootstrap.min.css">
    <!-- PopExtendCss -->
    <link href="./vendor/ncam/PopupExtended.css" rel="stylesheet" />

    <!-- PopupExtended references -->
    <script>
        var dojoConfig = {
            parseOnLoad: false,
            async: true,
            tlmSiblingOfDojo: false,
            packages: [{
                name: "ncam",
                location: location.pathname.replace(/\/[^/]+$/, '') + "ncam"
            }]
        };
    </script>

    <!-- ArcGIS API for JavaScript library references -->
    <script src="//js.arcgis.com/3.10"></script>

    <!-- Terraformer reference -->
    <script src="./vendor/terraformer/terraformer.min.js"></script>    
    <script src="./vendor/terraformer-arcgis-parser/terraformer-arcgis-parser.min.js"></script>

    <!-- other reference -->
    <script src="./vendor/jquery.js"></script>
</head>
<body>

</body>
</html>

  加入底图所需要的div与图层切换的Button:

<body>
     <div id="mapDiv"></div>
     <button type="line" id="shanghaiPoint" class="btn btn-default buttonRight" style="top:20px;right:20px">上海区各点</button>
     <button type="point" id="threeLine" class="btn btn-default buttonRight" style="top:70px;right:20px">三条航线</button>
</body>

3.置入Popupextended并扩充geojsonlayer.js  

  然后从geojsonlayer.js源码入手,开始将PopupExtended扩展其中,让我们新构建的geojsonlayer直接可拥有多个Popup。在geojsonlayer.js的constructor中很容易可以找出infotemplate的set方法:

            // Default popup
            if (options.infoTemplate !== false) {
                this.setInfoTemplate(options.infoTemplate || new InfoTemplate("GeoJSON Data", "${*}"));
            }

  很明显,geojsonlayer初始化时通过options传入参数进行判断并构造,所以实现本文目的的大致思路是将这里的setInfoTemplate替换成可以扩展的PopupExtended:

if (options.infoTemplate !== false) {
                //① create a PopupTemplate
                var template = new PopupTemplate({
                        title: "{name}",
                        fieldInfos: [
                            { fieldName: "Id", label: "Id", visible: true },
                            { fieldName: "publishdate", label: "观测日期", visible: true },
                            { fieldName: "waveheight", label: "浪高", visible: true },
                            { fieldName: "wavedirection", label: "浪向", visible: true },
                            { fieldName: "windspeed", label: "风速", visible: true },
                            { fieldName: "winddirection", label: "风向", visible: true },
                            { fieldName: "comfort", label: "等级", visible: true }
                        ],
                        extended: { 
                            actions: [
                                { text: " IconText", className: "iconText", title: "Custom action with an icon and Text", click: function (feature) { alert("Icon Text clicked on " + "id: " + feature.attributes.id + " " + feature.attributes.name); } },
                                { text: "", className: "iconOnly", title: "Custom action only using an icon", click: function (feature) { alert("Icon action clicked on " + "id: " + feature.attributes.id + " " + feature.attributes.name); } }                          
                            ],
                         //uses a pretty bad custom theme defined in PopupExtended.css.
                             scaleSelected: 1.6
                        }
                    });
                //② create a extend for basemap
                var extendedPopup = new PopupExtended({
                        extended: {
                            themeClass: "light",
                            draggable: true,
                            defaultWidth: 250,
                            actions: [{
                                text: "其他", className: "defaultAction", title: "Default action added in extendedPopup properties.",
                                click: function (feature) { alert("clicked feature - " + feature.attributes); }
                            }],
                            hideOnOffClick: false,
                            multiple: true,
                        },
                        highlight: false,
                        //titleInBody: false,
                    }, dojo.create("div"));
                    
                //③set the map to use the exteneded popup
                extendedPopup.setMap(options.baseMap);
                options.baseMap.infoWindow = extendedPopup;

                this.setInfoTemplate(options.infoTemplate || template);
            }

  由上段代码可见,引入Popup给GeoJSON共分为三步:①实例化一个你需要的PopupTemplate(这里起名为template),可指定你需要展示的主题、数据项及扩展的一些交互action;②实例化一个PopupExtended并设置一些默认的Popup属性;③将实例化的PopupExtended——extendedPopup的Map设置为baseMap,并将baseMap的infowindow设置为extendedPopup,最后将geojsonlayer的infoTemplate设置为新构建的template。这样便可以实现对置入底图的geojsonlayer进行多个infoTemplate展示需求了。源代码见github:展示效果如图3:

 

图3 对geojsonlayer扩充Popupextended后的显示效果

  如若只需增加多个Popup至geojsonlayer的话,以上部分足以实现了。

4.增加新的Attributes及调整Popup的样式  

  由于设计上的需求,笔者需要从其他地址获取观测点的部分观测值,并且笔者的老师觉得应该加一些icon给属性,美化展示效果,所以需要重新构造两部分:①获取并为graphics增加新的attributes;②重构geojsonlayer的infoTemplate的content。

4.1 获取并为graphics增加新的attributes:

  通过在button上利用fetch及Promise.all来同时获取6个点或3条航线的数据,并传入至初始化geojsonlayer的函数内;

$("#shanghaiPoint").click(function(){
            // if first init geojsonlayer
            if(firstPointInit){
                var requestBZ = 'http://wx.dhybzx.org:18080/forecast/shanghai_sea_env/80';
                var requestWGQ = 'http://wx.dhybzx.org:18080/forecast/shanghai_sea_env/81';
                var requestHS = 'http://wx.dhybzx.org:18080/forecast/shanghai_sea_env/82';
                var requestLCG = 'http://wx.dhybzx.org:18080/forecast/shanghai_sea_env/83';
                var requestJHG = 'http://wx.dhybzx.org:18080/forecast/shanghai_sea_env/84';
                var requestJSW = 'http://wx.dhybzx.org:18080/forecast/shanghai_sea_env/85';
                var urls = [requestBZ, requestWGQ,requestHS,requestLCG,requestJHG,requestJSW]

                Promise.all(urls.map(url =>
                    fetch(url).then(resp => resp.json())
                )).then(results => {
                    
                var tempJson = {
                     "堡镇":results[0][0],
                     "外高桥":results[1][0],
                     "横沙":results[2][0],
                     "芦潮港":results[3][0],
                     "金汇港":results[4][0],
                     "金山卫":results[5][0]
                }
                
                addGeoJsonToMap("./data/six_point.json",tempJson)

                });
            }else{
                //geojsonlayer has been initial
                 addGeoJsonToMap("./data/six_point.json")
            }
        
        })

  这里的Promise.all采用了ES2015的箭头函数,兼容性问题需要自己考虑,也可以手动改成ES5支持的。将额外的attributes组装成tempJson后传入至初始化方法addGeoJsonToMap内。

4.2 重构geojsonlayer的infoTemplate的content:

  在geojsonlayer.js内继续做一部分修改,注释掉实例化template中的fieldInfos属性及值,并且为geojsonlayer的infoTemplate设置新的content,代码如下:

               var template = new PopupTemplate({
                        title: "{name}",
                        // fieldInfos: [
                        //     { fieldName: "Id", label: "Id", visible: true },
                        //     { fieldName: "publishdate", label: "观测日期", visible: true },
                        //     { fieldName: "waveheight", label: "浪高", visible: true },
                        //     { fieldName: "wavedirection", label: "浪向", visible: true },
                        //     { fieldName: "windspeed", label: "风速", visible: true },
                        //     { fieldName: "winddirection", label: "风向", visible: true },
                        //     { fieldName: "comfort", label: "等级", visible: true }
                        // ],
                        extended: { 
                            actions: [
                                { text: " IconText", className: "iconText", title: "Custom action with an icon and Text", click: function (feature) { alert("Icon Text clicked on " + "id: " + feature.attributes.id + " " + feature.attributes.name); } },
                                { text: "", className: "iconOnly", title: "Custom action only using an icon", click: function (feature) { alert("Icon action clicked on " + "id: " + feature.attributes.id + " " + feature.attributes.name); } }                          
                            ],
                         //uses a pretty bad custom theme defined in PopupExtended.css.
                             scaleSelected: 1.6
                        }
                    });
                //create a extend for basemap
                var extendedPopup = new PopupExtended({
                        extended: {
                            themeClass: "light",
                            draggable: true,
                            defaultWidth: 250,
                            actions: [{
                                text: "其他", className: "defaultAction", title: "Default action added in extendedPopup properties.",
                                click: function (feature) { alert("clicked feature - " + feature.attributes); }
                            }],
                            hideOnOffClick: false,
                            multiple: true,
                        },
                        highlight: false,
                        //titleInBody: false,
                    }, dojo.create("div"));
                    
                //set the map to use the exteneded popup
                extendedPopup.setMap(options.baseMap);
                options.baseMap.infoWindow = extendedPopup;

                this.setInfoTemplate(options.infoTemplate || template);
                this.infoTemplate.setContent("<b class='popupTitle'>${name}</b>" +
                                "<div class='hzLine'></div>"+
                                "<div class='popupContent'>"+
                                "<i class='glyphicon glyphicon-calendar'></i><b>日期: </b> ${publishdate}<br/>"+
                                "<i class='glyphicon glyphicon-resize-vertical'></i><b>浪高: </b> ${waveheight}<br/>" +
                                "<i class='glyphicon glyphicon-random'></i><b>浪向: </b> ${wavedirection}<br/>"+
                                "<i class='glyphicon glyphicon-share'></i><b>风速: </b> ${windspeed}<br/>" +
                                "<i class='glyphicon glyphicon-transfer'></i><b>风向: </b> ${winddirection}<br/>"+
                                "<i class='glyphicon glyphicon-export'></i><b>等级: </b> ${comfort}<br/>"+
                                "</div>"
                    );

  额外的属性和新的infoTemplate样式构造完成,但存在一个问题,即额外的attributes必须要在geojsonlayer绘制好后再进行设置并展示,arcgis提供了layer的layer-add及layer-add-result事件,但是无法监控到graphics是否已经增入至geojsonlayer内,所以必须要再做一些改进,使额外的属性能够在graphics绘制完毕后再添加进去。具体方法分为两步:1)初始化geojsonlayer时,将showAllPopup方法传入其构造函数内;2)在grahics添加至layer后,调用showAllPopup方法,显示所有的Popup。前端代码如下:

//add GeoJSON to baseMap , constuct show&hide popup method and add other attribute to graphics
        function addGeoJsonToMap(url,otherJson){
            
             require(["esri/map",
            "./src/geojsonlayer.js",
            "esri/geometry/Point", "esri/SpatialReference",
            "dojo/on",
            "dojo/dom",
            "dojo/domReady!"],
              function (Map, GeoJsonLayer, Point, SpatialReference,on, dom) {

                 var hasThisLayer=false;
                 otherJson=otherJson?otherJson:"";
                 hideAllPopup()
           //judge layer has been init
                   map.getLayersVisibleAtScale().forEach(function(item){
                       if(item._url==url&&item.dataType=="geojson"){
                           console.log(item)
                           item.show();
                           console.log("dd")
                           showAllPopup(item);
                           hasThisLayer=true;
                           // map.setExtent(item.extent)
                       }else if(item._url!=url&&item.dataType=="geojson"){
                           item.hide();
                       }
                   })

                   if(!hasThisLayer){
                       addGeoJsonLayer(url);                                  
                   }

                   //show all popups
                   function showAllPopup(layer){
                      ......
                   }

                   //hide all popups
                   function hideAllPopup(){
                     .......
                   }

                   //add other attribute to grpahics for popup
                   function addAttrToGrpahics(item,type){
                     .......
                   }
                

                // Add the layer
                function addGeoJsonLayer(url) {
                    // Create the layer
                    var geoJsonLayer = new GeoJsonLayer({
                        baseMap:map,
                        url: url,
                        onLayerLoaded:function(layer){
                            showAllPopup(layer);
                        }              
                    });

                    // Add to map
                    geoJsonLayer.dataType="geojson"; 
                    map.addLayer(geoJsonLayer);
                  
                   
                }
            });
        }

并且在geojsonlayer.js的constructor内加入:

this._onLayerLoaded = options.onLayerLoaded;

在最后的_addGraphics方法中onLoad方法后,加入:

if (this._onLayerLoaded) this._onLayerLoaded(this);

利用show/hide方法,控制popup显示及隐藏。

//open all popup
layer.graphics.forEach(function(item){
  if(firstPointInit&&otherJson[item.attributes.name]){
      addAttrToGrpahics(item,layer.graphics[0].geometry.type)
  }
  var loc = map.toScreen(item.geometry);
  map.infoWindow.setFeatures([item]);
  map.infoWindow.show(loc);
})
//hide all popup
var tempLength = map.infoWindow.openPopups.length;
for(var i=0;i<tempLength;i++){
  map.infoWindow.openPopups[0].hide()
}

5. 结论  

  至此,本文已经完成了在Arcgis for javascript API中实现Geojson的绘制,并同时展示其多个Popup的需求。最终的展示效果如图1、2。源代码见笔者的github:https://github.com/EasonXu818/Add-GeoJSON-Multiple-Popups

 

posted @ 2017-03-20 14:09 EasonXu 阅读(...) 评论(...) 编辑 收藏