Error handling

Every operation either resolves with a typed response or fails with a typed error. On Flutter and React Native the error type is PPA2AException; on the native package it is PlusPayException. All of them expose an error code and a message.

	Flutter	React Native	Native
Type	`PPA2AException`	`PPA2AException`	`PlusPayException`
Code	`errorCode`	`errorCode`	`getError_code()`
Message	`message`	`message`	`getError_message()`

Catching errors

try {
  final result = await _pluspay.startPayment(request);
  // success
} on PPA2AException catch (e) {
  print(e.errorCode); // e.g. "LAUNCH_INTENT_ERROR"
  print(e.message);   // human-readable message
}

Error codes

Branch on errorCode, never on the message text. Flutter (0.8.0+) and React Native (0.4.0+) also expose these codes as constants in PPA2AErrorCodes.

Returned by the client package

Code	Meaning
`LAUNCH_INTENT_ERROR`	POS+ could not be launched (not installed, or the intent could not be resolved).
`PP-A2A-PARSE`	The response from POS+ could not be parsed.
`PP_A2A_015`	Another request from your app is still waiting for its result. Flutter 0.8.0+ and React Native 0.4.0+ reject the new request immediately, without launching POS+.
`NOT_INITIALIZED`	React Native: `initialize()` was not called before the request.
`TIMEOUT`	Native package: no response from POS+ within the client timeout.

Returned by POS+

Code	Meaning
`PP-A2A-003`	The intent did not contain a `request` extra. Note the hyphens: this is not `PP_A2A_003`.
`PP_A2A_001`	The request is empty.
`PP_A2A_002`	This operation needs a `data` object, but it is missing or is not an object.
`PP_A2A_003`	The `client_token` in the header is invalid (only checked when a token is sent).
`PP_A2A_004`	Invalid end-of-day request: `is_all` is `false` but `types` is empty.
`PP_A2A_005`	Invalid parameter request: `is_all` is `false` but `types` is empty.
`PP_A2A_006`	Invalid request parameter.
`PP_A2A_007`	Unexpected error while handling the request. The final state is unknown: query it with `getTransactionResult` / `getOrderResult`.
`PP_A2A_008`	The `header` is missing.
`PP_A2A_009`	`transaction_type` is missing or not a known operation.
`PP_A2A_010`	A header field required by this operation is missing or empty (for example `order_code` or `transaction_id`).
`PP_A2A_011`	Nobody has ever logged in to POS+ on this device. Log in to POS+ once, then retry.
`PP_A2A_012`	The operation failed in POS+ (declined, cancelled by the user, order closed, …). The message describes the cause.
`PP_A2A_013`	POS+ could not log in automatically. Check the device's internet connection and the POS+ session.
`PP_A2A_014`	POS+ timed out: it could not get ready within 3 minutes, or the request did not finish within 15 minutes. The final state is unknown: query it.
`PP_A2A_015`	POS+ is still processing an earlier request. Wait for that result, then retry.
`PP_A2A_016`	`TRANSACTION_RESULT`: the order has no transaction with the given `transaction_id`.

error_message is always in Turkish, even when you set a locale. For example: "İşlem kullanıcı veya sistem tarafından iptal edildi!" ("The transaction was cancelled by the user or the system."). If you show errors to your users in another language, map errorCode to your own text.

Timeouts and concurrency

One request at a time. POS+ handles a single A2A request at a time. A second request that arrives while one is in progress is rejected with PP_A2A_015. Wait for the first result before you send the next request.
POS+ start-up: 3 minutes. If POS+ is launched by your request and cannot get ready to handle it within 3 minutes, it answers with PP_A2A_014.
Request handling: 15 minutes. If a request is not finished within 15 minutes, POS+ answers with PP_A2A_014. The limit is long on purpose so that a real payment flow (card reading, PIN entry, receipt) is never cut off.
Client-side timeouts. The Flutter and React Native packages don't time out on their own. If you add your own timeout, make it longer than 15 minutes. Otherwise a payment that completes in POS+ looks failed in your app.
After it sends the result, POS+ brings your app back to the foreground and moves itself to the background.

Recommended handling

Treat any thrown error as a non-completed transaction. Do not assume the payment succeeded.
For PP_A2A_007 and PP_A2A_014, the outcome is unknown. Query it with getTransactionResult / getOrderResult before you retry.
For LAUNCH_INTENT_ERROR, verify POS+ is installed and (Flutter) consider providing fallbackPackageName / fallbackActivityName during initialization.
For PP_A2A_011 and PP_A2A_013, ask the user to open POS+ and log in.