Event processing queues for angular and sap C4C

Angular

We can see a function named Processqueue in the code of the angular framework:

This function is initiated by the $scope. $apply:

The core code is in a for loop, and the loop body is a queue asyncqueueposition that stores asynchronous processing tasks:

for (var asyncQueuePosition = 0; asyncQueuePosition < asyncQueue.length; asyncQueuePosition++) {try {    asyncTask = asyncQueue[asyncQueuePosition];    fn = asyncTask.fn;    fn(asyncTask.scope, asyncTask.locals);} catch (e) {      $exceptionHandler(e);}     lastDirtyWatch = null;}

Each element in the queue is like this: a handler function, FN, a local variable locals, and a scope object:

This annotation is also useful: once angular discovers that the JavaScript execution sequence triggered by the $scope. $apply appears again in the $scope. $apply nested call that throws an error message: $digest already in progress

It's safe for asyncqueueposition-a local variable here because this loop can ' t

Be reentered recursively. Calling $digest from a function passed to $evalAsync would

Lead to a ' $digest already in progress ' error.

C4C Event Queue

C4C event handler, Eventprocessor.js has an event queue:

The implementation of this queue is in the operationqueue.js of sap/client/evt/:

Just do a click in the C4c UI, and the _PROCESSQUEUE,C4C event queue that can trigger Eventprocessor is the same as the angular idea, except that a while loop replaces the angular for loop:

Each element in the C4C event queue has the following attributes, which can be compared with the angular event element:

Ffunc is equivalent to the FN property of the angular time element, environment equivalent to the scope property of the angular event element.

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Event processing queues for angular and sap C4C