DataBasic | simple tools and activities for journalists , data

I have a shiny app where I have 2 filter choices ("an option" and "another option"). The timeline starts with "an option" selected. If the user selects an item in the timeline, some text appears. What I would like to do is set the input$timeline_selected value back to NULL if the user has selected something in the timeline, but then chooses a different filter choice before clearing the selection. For example, in this simple app, if the user has the filter set to "an option", then selects "item one" on the timeline, then changes the filter to "another option" before clearing the selection, the "selection id" is still 1 even though that item isn't shown on the timeline when the filter is changed.

What I would like to have happen is the following: user has filter set to "an option", then selects "item one" on the timeline, then changes the filter to "another option" (before clearing the selection), then the input$timeline_selected value gets reset to NULL.

I am building a shiny app with a timeline and a data table. What I would like to have happen is when the user clicks on an item in the timeline, the corresponding data in the table is highlighted.

I have come up with a solution for this, but it seems very hacky and R is giving me warning messages. Basically what I have done is created a flag in the data table that is 1 if that item is selected and 0 if it's not, then I format the row based on that flag. When I create the "selected" field, I get a warning because initially nothing is selected and mutate doesn't like the fact that input$timeline_selected is NULL. Also for some reason when I try to add the rownames = FALSE argument to datatable all the data in the table is filtered out (not sure what is happening there).

Anyway, I'm wondering if there is a better way to do this perhaps with HTML or CSS. I've tried looking, but I can't figure out how to do it.

Eventually I would also like to know how to highlight the rows in the data table if the user hovers over the item in the timeline rather than selects it.

Databasics.m

Databasics.h

I need to upgrade an objective-c based program from firebase 2.x to 3.x sdk. However, I meet some problems as you can see. I changed to the new reference style and corresponding declarations and new class names, but there is an error: use of undeclared identifier 'dataBasicsInstance'. Actually others functions are also have the same errors. I don't know how to solve it.