topic How to return value from nested function to parent function? in ArcGIS JavaScript Maps SDK Questions

How to return value from nested function to parent function?

JoanSteinbacher — Fri, 31 May 2013 17:58:47 GMT

I have the following code working, but I need to return the value of the resultant "fieldInfos" string to the createFieldInfos() function and I'm not sure how to do that. Can anyone point me in the right direction?

Thanks,
Joan

function createFieldInfos() {
 console.log("-->inside createFieldInfos function");
 var endpoint = "http://gis.tpcmaps.org/ArcGIS/rest/services/LandUse/Existing_Land_Use/MapServer/0";

 var jsonobject = esri.request({
  url: endpoint,
  content: { f: 'json' },
  callbackParamName: 'callback',
  load: processServiceInfo,
  error: errorHandler  
 });
 console.log("jsonobject: " + jsonobject);
}

function processServiceInfo(info) {
 console.log('layer info: ', info);
 console.log("info.name: " + info.name + ",info.id: " + info.id);

       var fieldInfos = "";
       fieldInfos += "[";
    
 dojo.forEach(info.fields, function(field) {
  console.log( "Name: " + field.name + ", Alias: " + field.alias);
  if (field.name != "Shape" & field.name != "OBJECTID") {
   fieldInfos += "{'fieldName': '" + field.name + "',";
   fieldInfos += "'label': '" + field.alias + "',"; 
   fieldInfos += "'visible':" + true + "},";    
  }
 });
 
 fieldInfos += "],";
 console.log("fieldInfos: " + fieldInfos);
}
function errorHandler(err) {
    console.log('error: ', err);
}

Re: How to return value from nested function to parent function?

KenBuja — Sun, 12 Dec 2021 02:57:33 GMT

This should do it

function processServiceInfo(info) {
    console.log('layer info: ', info);
    console.log("info.name: " + info.name + ",info.id: " + info.id);

       var fieldInfos = "";
       fieldInfos += "[";
    
    dojo.forEach(info.fields, function(field) {
        console.log( "Name: " + field.name + ", Alias: " + field.alias);
        if (field.name != "Shape" & field.name != "OBJECTID") {
            fieldInfos += "{'fieldName': '" + field.name + "',";
            fieldInfos += "'label': '" + field.alias + "',";    
            fieldInfos += "'visible':" + true + "},";                
        }
    });
    
    fieldInfos += "],";
    console.log("fieldInfos: " + fieldInfos);
    return fieldInfos;
}

Re: How to return value from nested function to parent function?

JoanSteinbacher — Fri, 31 May 2013 18:27:26 GMT

I've added that line but unfortunately it's still not working. Any other ideas?

Re: How to return value from nested function to parent function?

JeffJacobson — Sun, 12 Dec 2021 02:57:36 GMT

Try this:

function createFieldInfos() {
    var endpoint, jsonobject, fieldInfos = "";

    function processServiceInfo(info) {
        console.log('layer info: ', info);
        console.log("info.name: " + info.name + ",info.id: " + info.id);
        fieldInfos += "[";

        dojo.forEach(info.fields, function (field) {
            console.log("Name: " + field.name + ", Alias: " + field.alias);
            if (field.name != "Shape" & field.name != "OBJECTID") {
                fieldInfos += "{'fieldName': '" + field.name + "',";
                fieldInfos += "'label': '" + field.alias + "',";
                fieldInfos += "'visible':" + true + "},";
            }
        });

        fieldInfos += "],";
        console.log("fieldInfos: " + fieldInfos);
    }

    function errorHandler(err) {
        console.log('error: ', err);
    }

    console.log("-->inside createFieldInfos function");
    endpoint = "http://gis.tpcmaps.org/ArcGIS/rest/services/LandUse/Existing_Land_Use/MapServer/0";

    jsonobject = esri.request({
        url: endpoint,
        content: {
            f: 'json'
        },
        callbackParamName: 'callback',
        load: processServiceInfo,
        error: errorHandler
    });
    console.log("jsonobject: " + jsonobject);
}

Re: How to return value from nested function to parent function?

VinayBansal — Sun, 12 Dec 2021 02:57:39 GMT

Try this code

function createFieldInfos() {
 console.log("-->inside createFieldInfos function");
 var endpoint = "http://gis.tpcmaps.org/ArcGIS/rest/services/LandUse/Existing_Land_Use/MapServer/0";

 var jsonobject = esri.request({
  url: endpoint,
  content: { f: 'json' },
  callbackParamName: 'callback',
  load: processServiceInfo,
  error: errorHandler  
 });
 console.log("jsonobject: " + jsonobject);
 return jsonobject.then(processServiceInfo, errorHandler);
}

function processServiceInfo(info) {
 console.log('layer info: ', info);
 console.log("info.name: " + info.name + ",info.id: " + info.id);

       var fieldInfos = "";
       fieldInfos += "[";
    
 dojo.forEach(info.fields, function(field) {
  console.log( "Name: " + field.name + ", Alias: " + field.alias);
  if (field.name != "Shape" & field.name != "OBJECTID") {
   fieldInfos += "{'fieldName': '" + field.name + "',";
   fieldInfos += "'label': '" + field.alias + "',"; 
   fieldInfos += "'visible':" + true + "},";    
  }
 });
 
 fieldInfos += "],";
 console.log("fieldInfos: " + fieldInfos);
return fieldInfos;
}
function errorHandler(err) {
    console.log('error: ', err);
return null;
}

Re: How to return value from nested function to parent function?

VinayBansal — Sun, 12 Dec 2021 02:57:41 GMT

Remove load and error function from jsonObject declaration

var jsonobject = esri.request({
  url: endpoint,
  content: { f: 'json' },
  callbackParamName: 'callback'
});