When is ParamTrigger Executed?

AFL Programming
1

According to the docs on ParamTrigger it will trigger a one-shot code execution. My question is at what point the process of executing a back test does this triggered code get executed? Is it in phase 1 on the first symbol, or in phase 2 before anything before any other code, or at the end of phase 2 after all other code has been processed?

2

ParamTrigger is intended to be used in CHARTS only as it only then makes sense to "trigger" anything as it just causes chart refresh when you click on button.

3

You can easily see the behavior with a bit of test code like this:

eventTrigger = ParamTrigger("Event Trigger", "Press to Trigger");
if (eventTrigger)
{
	_TRACE("eventTrigger Activated");
}

Filter = True;
AddColumn(C, "Close");

Open the Parameters window and click the Event Trigger button. Watch the Log/Trace window to see when the output appears. It should be the next time your AFL is executed, which could be to refresh a chart as @Tomasz mentioned, or on the first symbol of an Exploration, or even when you go back into the Parameters window again.

4

Okay, looks like best used only for charting and a semaphore is a better choice for use in back testing.