Combining 2 arrays into 1 array

Use the Expand option of List Object Instances

The List Object Instances activity has an ‘Expand’ option, which allows you to collect, in one array, the details of two Tables, linked by a Reference field.

Consider a Table (called Permissions) which has a reference field called Feature.

In this example we have created two variables, simpleVariable using .Output() and expandedVariable using .ExpandedObject()

Workflow overview:

Listing the data:

Setting the simple variable:

Setting the expanded variable:

The resulting variables might look like this:

{
  "simpleVariable": {
    "$type": "System.Object[], System.Private.CoreLib",
    "$values": [
      {
        "OriginalVersion": null,
        "ObjectId": 25,
        "Feature": [
          "long",
          34
        ],
        "Title": "JIm - Access4 Charges"
      }
    ]
  },
  "expandedVariable": {
    "$type": "System.Object[], System.Private.CoreLib",
    "$values": [
      {
        "$id": "3",
        "$type": "System.Dynamic.ExpandoObject, System.Linq.Expressions",
        "ObjectId": 25,
        "OriginalVersion": null,
        "Feature": {
          "OriginalVersion": null,
          "ObjectId": 34,
          "Title": "Access4 Charges",
          "URL": "/access4Charges"
        },
        "Title": "JIm - Access4 Charges"
      }
    ]
  }
}

The details of the referenced Table, Features, is included in the ‘expandedVariable’ variable. This allows easy access to all of the fields of the referenced type.

JavaScript function

In addition to this built-in functionality, you may have a data structure that has two Tables with common (or even just similar) data columns, that you want to programmatically bring into one array.

function join2Tables(Primaries,Secondaries) {

    return Primaries.map(Primary => {
        // Find the corresponding entry for each in the secondary table 
        let Second = Secondaries.find(s => Primary.Purpose == s.ObjectId );  // this is using an exact match.  
        
        // another example:
        // Find the corresponding entry in Secondaries where the first 3 characters of Primary.Purpose match s.Purpose
        // let Second = Secondaries.find(s => Primary.Purpose.substring(0, 3) === s.Purpose);


        // Only return Primary and Second data if a matching Second is found
        if (Second) {
            return {
                ...Primary, // Spread operator to include all properties of chauffeur
                LinkedObject: Second, // Add the found Second object
                                    // LinkedObject will be a new field in the array.  Rename this as appropriate
            };
        } else {
        return undefined; // Explicitly return undefined for non-matches
        }
    }).filter(item => item !== undefined); // Filter out undefined items (where no matches occur)
}

// Example usage
let Secondaries = getVariable("FilePurposes"); 
let Primaries = getVariable("Files");

let combinedData = join2Tables(Primaries,Secondaries);
return combinedData

Here’s a brief explanation of how the function works:

1. Mapping Over Primaries: You iterate over each Primary object in the Primaries array.
2. Finding a Match: For each Primary, you find the corresponding Secondary object in the Secondaries array where Primary.Purpose matches s.ObjectId.
3. Creating a Combined Object: If a match is found (Second), you create a new object combining Primary and Second under a new property LinkedObject.
4. Filtering Undefined: After mapping, you filter out undefined values which occur when no matching Secondary is found.

You might want to consider renaming LinkedObject to something more descriptive depending on the context. This should give you a clear understanding of which Secondary is linked to each Primary and help make your data handling more intuitive.