How do I refer to a datatable's object in code?

Development Programming & Scripting C++
1

I’ve been trying to pick apart Data Driven Gameplay Elements | Unreal Engine Documentation and make my own example to be sure I understand the process, and I’m stuck on one step: I’ve made some arbitrary enum EMyEnum to hold a unique value, and a struct to hold each row of data from my table:


     USTRUCT(BlueprintType)
     struct FMyEnumDataRow : public FTableRowBase
     {
         GENERATED_USTRUCT_BODY()
             UPROPERTY(VisibleAnywhere, BlueprintReadOnly)
             EMyEnum EnumValue;
     };

I’ve already imported my CSV, used my struct as the data table row type, and verified that the data imported correctly by opening the data table (which I just named MyEnumTestDT) in the editor and viewing its contents.

Where I’m stuck is the next step, namely obtaining a reference to MyEnumTestDT in code so I can run searches across it. Once I have that reference (presumably as a UDataTable), I know I can find data by doing something like:


     int8 rowID;
     FMyEnumDataRow  = UDataTable->FindRow<rowID>

However, that’s all predicated on actually finding a reference to the data table in the first place. So how, given the presence of some UDataTable MyEnumTestDT in the content folder, do I obtain a reference to that data table in code?

2

You need to get the refrence to the Data Table.


	UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Data Tables")
		UDataTable* MyDataTable;

ANd then you can do something like this.


	UMyDataSingleton* DataTabels = UMyDataTablesLibrary::GetDataSingleton(bIsValid);
	if (DataTabels && bIsValid)
	{
		FMyTableStruct* Item = DataTabels->MyDataTable->FindRow<FMyTableStruct>(FName(*FString::FromInt(ItemRowID)), "", true);
		if (Item)
		{
			return *Item;
		}
		else {
			return FMyTableStruct();
		}
	}

Hope this helps.

1 Like
3

Hm okay, is the implication that there is some object that actually exists within the level who I hand a reference to the desired table in the editor?

4

In the case you are seeing above am refrencing a Singleton Class.
wrote a Wiki on this .

The Singleton is a class that can only have 1 instance.
It is not necesary but it insures you only allocate memory for the data once.

Then you can Create a Blueprint of the Singleton class and set the desierd data table in editor yes.
It is possible to set the Singleton by Searcing “Single” under General in your Project Settings.

5

Ooh perfect, thank you!! That clears up a lot :slight_smile:

6

You are welcome :).