Modify a timeline to execute within a loop

display_while(timeline, loop_function)



The timeline object


A javascript function that returns true if loop repeats, false if terminates


The modified timeline object


The display_while() function is used to modify an existing timeline object, and provides the ability to include while loops within an experiment. To use it, the user must supply the loop_function, a javascript function that executes at runtime and should evaluate to true or false. If the loop function returns true, then the timeline object will execute for another iteration; this condinues until the loop function returns false.

At present jaysire provides only limited tools for writing the loop function. The fn_data_condition() function allows a simple approach that allows the loop function to query the jsPsych data store, but only in a limited way. Future versions will (hopefully) provide a richer tool set for this. However, for users who are comfortable with writing javascript functions directly the insert_javascript() function may be useful.

See also