Data Expression Help in Dashboards

JanelleShank

Good Afternoon All, 

I am new to writing data expression to retrieve data for a hosted table in a dashboard and I am having trouble writing the expression to use in a pie chart on the Dashboard. For example, I need to write and expression that bring in the count of the Current Step field and the Project Name field. Ultimately the goal of the expression is to spring the attributes of the "Current Step' field and while providing a count of those attributes and filtering the counts by the Project Name. Below is my current code. I have been successful in get the Current Count to split and displaying the count of each of the choices but I am struggling to get the Project name to factor into the count. Will I need to write and expression to count the current step by the each individual project?

 

I appreciate any help and suggestions to solve this problem. 

 

var portal = Portal('')

var fs = FeatureSetByPortalItem(

    portal,

    '*',

    0,

    ['Current_Step'],

    false

);

// Create empty array for features and feat object

var features = [];

var feat;

var loc = FeatureSetByPortalItem(

    portal,

    'ddd2e78398c14777b49f902b9b289ada',

    0,

    ['Project_Name'],

    false

);

// Split comma separated hazard types and store in dictionary.  

for (var feature in fs) {

    var split_array  =  Split(feature['Current_Step'], "(")

    var count_arr = Count(split_array)

    for(var i = 0; i < count_arr; i++ ){

        feat = {

            'attributes': {

                'split_choices': Trim(split_array[i])

            }

        }

        Push(features, feat);

}}

// Empty dictionary to capture each hazard reported as separate rows.

var choicesDict = {

    'fields': [

        { 'name': 'split_choices', 'type': 'esriFieldTypeString'}],

    'geometryType': '',

    'features': features

};

// Convert dictionary to featureSet.

var fs_dict = FeatureSet(Text(choicesDict));

// Return featureset after grouping by hazard types.

return GroupBy(fs_dict, ['split_choices'],

       [{ name: 'split_count', expression: 'split_choices', statistic: 'COUNT' }]);

 

Thank you, 

Janelle 

JohannesLindner

Ah OK. So you want something like this:

// load your featureset
var fs = FeaturesetByPortalItem(Portal("https://arcgis.com"), "b0d335151aad48a5883326b9aed69cdd", 0, ["TextField1", "TextField2"], false)

// define the output featureset
var out_dict = {
  fields: [
    {name: "Project_Name", type: "esriFieldTypeString"},
    {name: "Current_Step", type: "esriFieldTypeString"}
  ],
  features: [],
  geometryType: ""
}

// iterate over the input fs
for(var f in fs) {
  // split the Current_Steps field
  var project_name = f.TextField1
  var steps = Split(f.TextField2, ",")
  // iterate over the split values
  for(var s in steps) {
    // create a new feature in the output featureset
    var new_f = {attributes: {Project_Name: project_name, Current_Step: Trim(steps[s])}}
    Push(out_dict.features, new_f)
  }
}
Console(out_dict)
// return the featureset
return Featureset(Text(out_dict))

 

Change the field names in lines 1, 17, 18. I used "TextField1" for the project name and "TextField2" for the current step.

 

You can use that expression to generate a featureset with the project name and the split values.

You can then input that fs into the pie chart widget:

 

 

Add a side or top bar widget. In there, you can add a category selector. Point it to the data expression and use the project name column as group field:

 

Set the category selector to filter the pie chart:

 

 

This is a quick example. The table on the left is my input featureset. The table on the right is the output of the data expression. The pie chart uses the same data expression.

 

When I select a project, each widget gets filtered to show only features that belong to that project: