Passing Attribute Value to Variable

LeviRoberts · ‎05-01-2014

We are trying to set up a simple application that only uses one layer. This layer is a grid for a mapbook. We want users to be able to click one of the grid features and it open a pdf on a separate window. The only thing I'm hung up on currently is trying to grab an attribute value and pass it to a variable. One of the attributes for the feature is the URL to the PDF.

var mapBook = new FeatureLayer("[Webservice]", {  mode: FeatureLayer.MODE_SNAPSHOT  });  map.addLayer(mapBook);  mapBook.on("click", function(evt) {  var url = [Need to pass attribute value here];         window.open(url);  });

Do I need to use Query or Identify task? Or is there something else?

JakeSkinner · ‎05-01-2014

Hi Steve,

You could use the following:

mapBook.on("click", function(evt) {           var url = evt.graphic.attributes.<field name>;           window.open(url); });

Simply replace <field name> with the field name that contains the URL.

View solution in original post

JakeSkinner · ‎05-01-2014

Hi Steve,

You could use the following:

mapBook.on("click", function(evt) {           var url = evt.graphic.attributes.<field name>;           window.open(url); });

Simply replace <field name> with the field name that contains the URL.

JakeSkinner · ‎05-01-2014

One other thing, you will need to specify the outFields parameter for the Feature Layer:

var mapBook = new FeatureLayer("[Webservice]", {
    mode: FeatureLayer.MODE_SNAPSHOT,
    outFields: ["*"]
});

LeviRoberts · ‎05-01-2014

Perfect. Works like a charm now. Thanks for your help.

MichaelVolz · ‎05-01-2014

Steve:

Have you been able to get your sample to work with Jake's comments?

I tried the sample with other additional required items and it does not work.

Could you post all the code for your sample?

JakeSkinner · ‎05-01-2014

Steve,

Could you mark this thread as 'resolved/answered' to help other users in the community?

Thanks!

MichaelVolz · ‎05-01-2014

Here is my sample that hopefully someone can see where I am going wrong as I am getting errors and unable to get the attribute from the Feature Layer - I cannot get the app to show the URL value in the line console.log("url = ", url); below:

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    
    <meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no">
    <title>FeatureLayer On Demand</title>

    <link rel="stylesheet" href="http://js.arcgis.com/3.9/js/dojo/dijit/themes/claro/claro.css">
    <link rel="stylesheet" href="http://js.arcgis.com/3.9/js/esri/css/esri.css">
    <style>
      html, body, #mapDiv {
        padding:0;
        margin:0;
        height:100%;
      }
    </style>
    <script src="http://js.arcgis.com/3.9/"></script>
    <script>
      var map;
      require([
        "esri/map", "esri/layers/FeatureLayer",
        "dojo/parser", "dojo/domReady!"
      ], function(
        Map, FeatureLayer,
        parser
      ) {
        parser.parse();
        map = new Map("mapDiv", {
          basemap: "national-geographic",
          center: [-75.56, 40.0025],
          zoom: 10
        });

var parcels = new FeatureLayer("Feature Layer REST endpoint URL", {
   mode: FeatureLayer.MODE_SNAPSHOT,
   outFields: ["*"]
});
console.log("hello");
map.addLayer(parcels);

parcels.on("click", function(evt) {
var url = evt.graphic.attributes.UPI;
   console.log("url = ", url);
    });

      });
    </script>
</head>
<body class="claro">
    <div id="mapDiv">
    </div>
</body>
</html>

Can anyone see what I am doing wrong?

JakeSkinner · ‎05-01-2014

Hi Mike,

Your code looks correct. Be sure the field you are referencing is 'UPI' and not 'upi'. Here is an example of your code with a sample service:

<!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>FeatureLayer On Demand</title>

    <link rel="stylesheet" href="http://js.arcgis.com/3.9/js/dojo/dijit/themes/claro/claro.css">
    <link rel="stylesheet" href="http://js.arcgis.com/3.9/js/esri/css/esri.css">
    <style>
      html, body, #mapDiv {
        padding: 0;
        margin: 0;
        height: 100%;
      }
    </style>
    <script src="http://js.arcgis.com/3.9/"></script>
    <script>
      var map;
      require(["esri/map", "esri/layers/FeatureLayer", "dojo/parser", "dojo/domReady!"], function(Map, FeatureLayer, parser) {
        parser.parse();
        map = new Map("mapDiv", {
          basemap : "national-geographic",
          center : [-81.792107, 26.150807],
          zoom : 9
        });

        var parcels = new FeatureLayer("http://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer/0", {
          mode : FeatureLayer.MODE_SNAPSHOT,
          outFields : ["*"]
        });

        map.addLayer(parcels);

        parcels.on("click", function(evt) {
          var url = evt.graphic.attributes.areaname;
          console.log("url = ", url);
        });

      });
    </script>
  </head>
  <body class="claro">
    <div id="mapDiv"></div>
  </body>
</html>

KenBuja · ‎05-01-2014

Check the capabilities of your map service. I noticed that when using a service like Jake did, it works fine. However, if I used a service from an older server (http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer/3, for example), the click event would never get activated.

MichaelVolz · ‎05-01-2014

Jake:

First off thanks for posting my modified sample with your layers.

I have some follow-up questions.

1.) Do you have to use a FeatureLayer to achieve this functionality?

2.) Can you call the data another way as there is by default a 1000 feature limit (This can be increased but it takes a toll on application performance)?

I ask this because I have a feature layer with over 100,000 features and I only saw 1 feature in the map extent I was using which I'm now thinking was because this was the only feature visible in the first 1000 records of the 100,000 record feature layer.