Call a Function - C++ SDK

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Call a Function By Name

Atlas Device SDKs are deprecated. Refer to the deprecation page for details.

The examples on this page demonstrate calling an Atlas Function named concatenate that takes two arguments, concatenates them, and returns the result:

// concatenate: concatenate two strings
exports = function(a, b) {
  return a + b;
};

Call a Function By Name

Important

Make sure to sanitize client data to protect against code injection when using Functions.

To execute a function from the C++ SDK, use the call_function() member function on the user object. Pass in the name of the function as a string for the first parameter. This function takes two arguments, which we provide as a string array of arguments:

// Connect to an App Services App and authenticate a user
auto appConfig = realm::App::configuration();
appConfig.app_id = APP_ID;
auto app = realm::App(appConfig);
auto user = app.login(realm::App::credentials::anonymous()).get();
auto sync_config = user.flexible_sync_configuration();
// If the function takes arguments, pass them as a string array.
// Any quotes within the array must be escaped.
auto argArray = "[\"john.smith\", \"@companyemail.com\"]";
// Call an App Services function as the logged-in user
auto result = user.call_function("concatenate", argArray).get();
// Verify that the result has a value
CHECK(result);
auto functionResult = result.value();
// Prints "Calling the concatenate function returned
// "john.smith@companyemail.com"."
std::cout << "Calling the concatenate function returned " << functionResult
          << ".\n";

The callback can provide an optional string result, or an optional error. In the example above, we check that the result has a value.

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