Blue prism code stage for extracting collection data

Question

I have collection which gets populated during execution and hence has no Fields declared. I need to extract the values of last column, and number of columns is dynamic, and am not able to do so. How can I do this with or without using code stage? (Code: VB only, as I have other code blocks running VB)

I have tried to replace the value with another variable in calculation stage like this: [my_collection.[column_name]]. It's throwing an Error when I press on Validate expression.

Answer 1

It's frankly a bit overkill to use custom code stages for something this simple, especially considering the maintainability trade-off is almost always not going to be worth it in the long-run.

Using the Utility - Collection Manipulation VBO, you can string the following actions together to achieve your desired functionality:

1. Action: Get Column Names
   

   • Object: Utility - Collection Manipulation
   • Input: My_Collection
     
   • Output: Column Names - My_Collection (Collection)

2. Loop Start
   

   • Collection: Column Names - My_Collection

3. Action: Count Columns

   • Object: Internal -> Collections
   • Input: "My_Collection"
   • Output: Count of Columns - My_Collection (Number)

4. Decision: Is this the last Column?

   • Expression: [Count of Columns - My_Collection] <= 1
   • Yes path: #7
   • No path: #5

5. Action: Delete Column

   • Object: Utility - Collection Manipulation
   • Input (Input Collection): [My_Collection]
   • Input (Column Name): [Column Names - My_Collection.Field Name]
   • Output (Output Collection): [My_Collection]

6. Loop End

7. Action: Rename Field
   

   • Object: Utility - Collection Manipulation
   • Input (Collection In): My_Collection
     
   • Input (Field Name): [Column Names - My_Collection.Field Name]
   • Input (New Name): "Result" (or a name of your choice)
   • Output (Output Collection): [My_Collection]

8. Loop Start

   • Collection: My_Collection

9. Processing Logic

   • Use expression [My_Collection.Result] to refer to the value in the current row

10. Loop End