Hi Dojo
Imagine an HTTP protocol with two sessions defined, each containing one request and one response. The response of session A is a comma-separated string of device IDs: “1,2,3,4,5”. The request of session B requires a device ID so session B needs to be executed for all device IDs.
To achieve this, I want to create a looping mechanism with a queue of device IDs. After a successful execution of session A, session B must be executed in a loop, starting with requestB(“1”) > requestB(“2”) > requestB(“3”) until the queue is empty. Response A is processed by QAction A and response B is processed by QAction B.
First I was thinking to set the device ID string to a parameter from QAction A and read that parameter in QAction B. Then I noticed that a static class (with a static property) in the precompiled (shared) QAction could also be used to store the device ID string. Now I’m wondering what’s the suggested approach to store this device ID string?
Since the number of interactions between SLScripting, the process executing the QAction, and other processes should be limited to an absolute minimum, I would think that saving the device ID string in a static class would be the best solution but I’m not entirely sure. Can somebody confirm if my assumption is correct? Maybe there is a different approach?
Thank you in advance!
Kind regards
Hi Jorge. Ok that’s clear. Thank you for your comment!
Hi Michiel, what I typically do is creating a static field in that QAction. The value of that field is shared across all elements on that DMA. Best is to use a ConcurrentDictionary with the element ID as key. Then you can retrieve the object that contains the data for that particular element.
Another approach is using async/await: https://github.com/TomW-Skyline/HTTP-Async-Demo/blob/master/QAction_500/QAction_500.cs#L57
Hi Michiel,
Have you considered using a single QAction to process response A and B? In that case, you could store the queue (with all device IDs you still need to retrieve) and the device ID (you are currently retrieving) in a non-static variable in memory.
In this case, you would not have to store any buffer temporarily in a parameter and it’s straightforward to implement.
If you use a static variable it will be shared by all elements using the same protocol/version in the DMA.
Having a parameter with the buffer content should be enough for what you need, make a condition on QAction to stop the loop when the buffer content is empty.