Cannot write data into the whole timeline when data is writen in individual trials

[Qiuishere]

Hi!

Thanks for the useful tool! I have a question about data writing. I'd like to add a label of which block it is for all the trials, so I add this whichblock property to the block timeline like this. blockArray is an object with length of 4, each corresponds to all the trials of a block.

var Bs = []
    for (let i = 0; i < blockArray.length; i++) {
        Bs.push({
            timeline: aTrial,
            timeline_variables: blockArray[i],
            randomize_order: false,
            **on_finish: function(data){
                data.whichblock = i
            },**
        })
    }

Generally it works, most trials will have a column called whichblock with the index of the current block (0, 1, 2, 3) in it.
However, in certain trials, the value of whichblock is missing. If a trial object also writes data, i.e., it has

        on_finish (or on_start): function(data) {
            data.resp = 1;
        }

then the whichblock value of this trial will be empty. Even the property I tried to write in this trial object has nothing to do with whichblock. I tried to put this function(data) in different trials like fixation, image presentation, etc, the whichblock will disappear for these trials.

I wonder is there any conflict between data writing in individual trials and the global timeline? How can I write something in each trial of the whole block? (Now I circumvent this problem by fetching data from other trials which have whichblock value and adding it to the trial in which I need to write data data.whichblock = jsPsych.data.get().last(2).values()[0].whichblock; , but sometimes this is not applicable)

Thanks so much for any help!
Qiu