我希望根据识别任务的结果查询图层的任何附件。如果图层上有附件，我想将链接添加到infoTemplate的底部。
我在处理多个dojo Deferred对象时遇到问题。我知道他们正在解决，因为返回值记录在控制台中，但我的infoWindow从未填充。
那么处理几个嵌套延迟的正确方法是什么？延迟列表似乎是朝着正确方向迈出的一步，但我不确定在这种情况下我将如何格式化。
谢谢，
乔
更新
我已在下面更新了我的工作代码。
map.on('click',executeIdentify);
function executeIdentify(evt) {
identifyParams.width = map.width;
identifyParams.height = map.height;
identifyParams.geometry = evt.mapPoint;
identifyParams.mapExtent = map.extent;
var deferred = identifyTask.execute(identifyParams);
deferred.addCallback(function(deferredResult){
var promiseList = []
var features = array.map(deferredResult,function(result) {
var feature = result.feature;
var content = "";
array.forEach(Object.keys(feature.attributes),function(attr) {
content += attr + ": " + feature.attributes[attr] + "<br>"
});
var url = identifyTask.url + "/" + result.layerId + "/" + result.feature.attributes.OBJECTID + "/attachments?f=json"
var req = esriRequest({url:url}).then(function(newDef) {
if (Object.keys(newDef).toString() == "attachmentInfos,_ssl") {
content += "<br><b>Attachments:</b><hr>"
array.forEach(newDef.attachmentInfos,function(attach) {
content += "<a href=" + identifyTask.url + "/" + result.layerId + "/" + result.feature.attributes.OBJECTID + "/attachments/" + attach.id + " target='_blank'>" + attach.name + "</a><br>"
})
}
content += "<br><br>";
console.log(result)
feature.infoTemplate = new InfoTemplate(result.layerName + " " + result.feature.attributes.OBJECTID,content)
// console.log(feature)
return feature
},function(newDef) {
feature.infoTemplate = new InfoTemplate(result.layerName + " " + result.feature.attributes.OBJECTID,content);
// console.log(feature)
return feature
});
promiseList.push(req);
});
var promiseAll = new all(promiseList)
promiseAll.then(function(r) {promiseFun(r)})
})
function promiseFun(r) {
map.infoWindow.setFeatures(r);
map.infoWindow.show(evt.mapPoint);
}
}
答案 0 :(得分：3)
您应该考虑使用dojo/promise/all来处理多个延迟结果。这是一个使用它来返回多个服务的结果的示例，还有一些额外的代码来识别结果来自哪个服务。
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<!--The viewport meta tag is used to improve the presentation and behavior of the samples
on iOS devices-->
<meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no">
<title>Identify with Popup</title>
<link rel="stylesheet" href="http://js.arcgis.com/3.8/js/esri/css/esri.css">
<style>
html, body, #map {
height: 100%;
width: 100%;
margin: 0;
padding: 0;
}
</style>
<script>var dojoConfig = { parseOnLoad: true };</script>
<script src="http://js.arcgis.com/3.8/"></script>
<script>
var map;
var identifyTask, identifyParams, idPoint;
var identifyResults;
require([
"esri/map", "esri/dijit/Popup", "dojo/promise/all", "dojo/domReady!"
], function (
Map, Popup, All
) {
var popup = new Popup({
fillSymbol: new esri.symbol.SimpleFillSymbol(esri.symbol.SimpleFillSymbol.STYLE_SOLID, new esri.symbol.SimpleLineSymbol(esri.symbol.SimpleLineSymbol.STYLE_SOLID, new dojo.Color([255, 0, 0]), 2), new dojo.Color([255, 255, 0, 0.25]))
}, dojo.create("div"));
map = new Map("map", {
basemap: "satellite",
center: [-83.275, 42.573],
zoom: 18,
infoWindow: popup
});
dojo.connect(map, "onLoad", mapReady);
var landBaseLayer = new esri.layers.ArcGISDynamicMapServiceLayer("http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/BloomfieldHillsMichigan/Parcels/MapServer", { opacity: .55 });
map.addLayer(landBaseLayer);
var militaryLayer = new esri.layers.ArcGISDynamicMapServiceLayer("http://sampleserver6.arcgisonline.com/arcgis/rest/services/Military/MapServer", { opacity: .55 });
map.addLayer(militaryLayer);
function mapReady(map) {
dojo.connect(map, "onClick", runIdentifies);
}
function runIdentifies(evt) {
identifyResults = [];
idPoint = evt.mapPoint;
var layers = dojo.map(map.layerIds, function (layerId) {
return map.getLayer(layerId);
});
layers = dojo.filter(layers, function (layer) {
if (layer.visibleLayers[0] !== -1) {
return layer.getImageUrl && layer.visible
}
}); //Only dynamic layers have the getImageUrl function. Filter so you only query visible dynamic layers
var tasks = dojo.map(layers, function (layer) {
return new esri.tasks.IdentifyTask(layer.url);
}); //map each visible dynamic layer to a new identify task, using the layer url
var defTasks = dojo.map(tasks, function (task) {
return new dojo.Deferred();
}); //map each identify task to a new dojo.Deferred
var params = createIdentifyParams(layers, evt);
var promises = [];
for (i = 0; i < tasks.length; i++) {
promises.push(tasks[i].execute(params[i])); //Execute each task
}
var allPromises = new All(promises);
allPromises.then(function (r) { showIdentifyResults(r, tasks); });
}
function showIdentifyResults(r, tasks) {
var results = [];
var taskUrls = [];
r = dojo.filter(r, function (result) {
return r[0];
});
for (i = 0; i < r.length; i++) {
results = results.concat(r[i]);
for (j = 0; j < r[i].length; j++) {
taskUrls = taskUrls.concat(tasks[i].url);
}
}
results = dojo.map(results, function (result, index) {
var feature = result.feature;
var layerName = result.layerName;
var serviceUrl = taskUrls[index];
feature.attributes.layerName = result.layerName;
var template = new esri.InfoTemplate("", "Service Url: " + serviceUrl + "<br/><br/>Layer name: " + result.layerName + "<br/><br/> Object Id: ${OBJECTID}");
feature.setInfoTemplate(template);
var resultGeometry = feature.geometry;
var resultType = resultGeometry.type;
return feature;
});
if (results.length === 0) {
map.infoWindow.clearFeatures();
} else {
map.infoWindow.setFeatures(results);
}
map.infoWindow.show(idPoint);
return results;
}
function createIdentifyParams(layers, evt) {
var identifyParamsList = [];
identifyParamsList.length = 0;
dojo.forEach(layers, function (layer) {
var idParams = new esri.tasks.IdentifyParameters();
idParams.width = map.width;
idParams.height = map.height;
idParams.geometry = evt.mapPoint;
idParams.mapExtent = map.extent;
idParams.layerOption = esri.tasks.IdentifyParameters.LAYER_OPTION_VISIBLE;
var visLayers = layer.visibleLayers;
if (visLayers !== -1) {
var subLayers = [];
for (var i = 0; i < layer.layerInfos.length; i++) {
if (layer.layerInfos[i].subLayerIds == null)
subLayers.push(layer.layerInfos[i].id);
}
idParams.layerIds = subLayers;
} else {
idParams.layerIds = [];
}
idParams.tolerance = 3;
idParams.returnGeometry = true;
identifyParamsList.push(idParams);
});
return identifyParamsList;
}
});
</script>
</head>
<body>
<div id="map"></div>
</body>
</html>