SQL Server

Call a JavaScript Function Returning an Object

See more JavaScript Examples

Demonstrates how to call a JavaScript function that returns an object. SQL Server

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    -- This is the JavaScript function we'll call:

    -- function getSettings() {
    --     return {
    --         theme: "dark",
    --         notifications: true,
    --         version: 1.0
    --     };
    -- }

    DECLARE @sbScript int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbScript OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OAMethod @sbScript, 'Append', @success OUT, 'function getSettings() {'
    EXEC sp_OAMethod @sbScript, 'Append', @success OUT, '    return {'
    EXEC sp_OAMethod @sbScript, 'Append', @success OUT, '        theme: "dark",'
    EXEC sp_OAMethod @sbScript, 'Append', @success OUT, '        notifications: true,'
    EXEC sp_OAMethod @sbScript, 'Append', @success OUT, '        version: 1.0'
    EXEC sp_OAMethod @sbScript, 'Append', @success OUT, '    };'
    EXEC sp_OAMethod @sbScript, 'Append', @success OUT, '}'

    DECLARE @js int
    EXEC @hr = sp_OACreate 'Chilkat.Js', @js OUT

    DECLARE @result int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @result OUT

    EXEC sp_OASetProperty @result, 'EmitCompact', 0

    -- Call Eval to add the function to the context's global object
    EXEC sp_OAMethod @js, 'Eval', @success OUT, @sbScript, @result
    IF @success = 0
      BEGIN
        -- Examine the result for an exception.
        EXEC sp_OAMethod @result, 'Emit', @sTmp0 OUT
        PRINT @sTmp0

        -- Also examine the LastErrorText.
        EXEC sp_OAGetProperty @js, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbScript
        EXEC @hr = sp_OADestroy @js
        EXEC @hr = sp_OADestroy @result
        RETURN
      END

    -- ------------------------------------------------------------------------------
    -- Call the function getSettings()

    DECLARE @funcCall int
    EXEC @hr = sp_OACreate 'Chilkat.JsonObject', @funcCall OUT

    -- Create JSON specifying the function name and arguments
    -- The function has no arguments, so we only specify the name.

    -- {
    --   "name": "getSettings",
    -- }

    EXEC sp_OAMethod @funcCall, 'UpdateString', @success OUT, 'name', 'getSettings'

    EXEC sp_OAMethod @js, 'CallFunction', @success OUT, @funcCall, @result
    IF @success = 0
      BEGIN
        -- Examine the result for an exception.
        EXEC sp_OAMethod @result, 'Emit', @sTmp0 OUT
        PRINT @sTmp0

        -- Also examine the LastErrorText.
        EXEC sp_OAGetProperty @js, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbScript
        EXEC @hr = sp_OADestroy @js
        EXEC @hr = sp_OADestroy @result
        EXEC @hr = sp_OADestroy @funcCall
        RETURN
      END

    EXEC sp_OAMethod @result, 'Emit', @sTmp0 OUT
    PRINT @sTmp0

    -- Output:
    -- {
    --   "type": "object",
    --   "value": {
    --     "theme": "dark",
    --     "notifications": true,
    --     "version": 1
    --   }
    -- }

    -- Examine the object's members

    EXEC sp_OAMethod @result, 'StringOf', @sTmp0 OUT, 'value.theme'
    PRINT 'theme: ' + @sTmp0

    EXEC sp_OAMethod @result, 'BoolOf', @iTmp0 OUT, 'value.notifications'
    PRINT 'notifications: ' + @iTmp0

    EXEC sp_OAMethod @result, 'IntOf', @iTmp0 OUT, 'value.version'
    PRINT 'version: ' + @iTmp0

    -- Output:
    -- theme: dark
    -- notifications: True
    -- version: 1

    EXEC @hr = sp_OADestroy @sbScript
    EXEC @hr = sp_OADestroy @js
    EXEC @hr = sp_OADestroy @result
    EXEC @hr = sp_OADestroy @funcCall


END
GO