Parameter Passing Between Actions

An action script keeps no variables between runs. Every click starts a fresh batch, so anything you need on the next run has to travel there explicitly. TSQL.APP gives you four routes, and choosing the right one is most of the work.

And one route you never have to build: the context variables. @id, @ids, @card_name, @user and the others are already set when your script starts. Never declare them yourself.

1. Within a dialog: named controls

Every control with a @name sends its value back on the next run. Reading it is one call:

EXEC sp_api_modal_get_value @name = N'@Quantity', @value = @Quantity OUT;

This covers most needs. The name is the key: give every control its own name and its own variable.

Pickers are the exception. sp_api_modal_select, sp_api_modal_select_table and sp_api_modal_choose read their own posted value when they are drawn and return it through their @value OUT parameter — the chosen id, not the raw posted data. For those, the call that draws the control is the synchronisation.

2. Across a restart: @values

When the script restarts itself — typically to move a wizard forward — the values to carry go in a JSON object. Each key is the name the next run will read:

SET @Json = (
    SELECT [@Step] = 2, [@CustomerId] = @CustomerId, [@OrderDate] = @OrderDate
    FOR JSON PATH, WITHOUT_ARRAY_WRAPPER
);
EXEC sp_api_modal_restart @values = @Json;
RETURN;

On the next run, sp_api_modal_get_value @name = N'@CustomerId' returns the value, exactly as if the user had typed it. Only what you put in the JSON comes along; everything else starts empty.

3. Into another action: @action_name

Add @action_name and the restart starts a different action, seeded with your values. This lets you split a long process into small, separately testable actions.

The sending action — a picker that hands the chosen product to an editor:

DECLARE @ProductId   NVARCHAR(MAX);
DECLARE @OpenButton  NVARCHAR(MAX);
DECLARE @Json        NVARCHAR(MAX);

EXEC sp_api_modal_get_value @name = N'@OpenButton', @value = @OpenButton OUT;

EXEC sp_api_modal_text   @text = N'Choose a product', @class = N'h4';
-- A picker reads its own posted value: no sp_api_modal_get_value for @ProductId
EXEC sp_api_modal_select @card_name = N'products', @name = N'@ProductId', @value = @ProductId OUT;
EXEC sp_api_modal_button @name = N'@OpenButton', @value = N'Edit',
                         @valueout = @OpenButton OUT, @class = N'btn-primary';

IF @OpenButton IS NULL OR @ProductId IS NULL RETURN;

SET @Json = (SELECT [@ProductId] = @ProductId FOR JSON PATH, WITHOUT_ARRAY_WRAPPER);
EXEC sp_api_modal_restart @action_name = N'product_edit', @values = @Json;
RETURN;

The receiving action, product_edit, reads @ProductId like any other value:

DECLARE @ProductId NVARCHAR(MAX);
DECLARE @Message   NVARCHAR(MAX);

EXEC sp_api_modal_get_value @name = N'@ProductId', @value = @ProductId OUT;

IF @ProductId IS NULL
BEGIN
    SET @Message = N'Open this dialog from the product picker.';
    EXEC sp_api_modal_alert @alert_text = @Message;
    RETURN;
END

-- ... draw the edit form for this product ...

Two habits keep this robust:

• The receiver checks its input. It can also be started some other way, so it should never assume the value is there.
• Keep the payload small — ids rather than whole records. The receiver looks up the rest itself, which also means it always shows current data.

4. Across sessions: sp_api_modal_set and sp_api_modal_get

For a value that should outlive the dialog — the last warehouse a user picked, a preferred date range — store it per user:

DECLARE @Warehouse NVARCHAR(MAX);

EXEC sp_api_modal_get @key = N'preferred_warehouse', @value = @Warehouse OUT;   -- read
EXEC sp_api_modal_set @key = N'preferred_warehouse', @value = @Warehouse;       -- write
EXEC sp_api_modal_set @key = N'preferred_warehouse', @value = NULL;             -- forget

These values belong to the logged-in user and persist until you overwrite them, so they suit preferences, not temporary hand-overs. For a value shared by the whole application, use App Settings instead.