Data Flow
In teal: Exploratory Web Apps for Analyzing Clinical Trials Data

shiny::pre(
  class = "mermaid",
  "
%% This is a mermaid diagram, if you see this the plot failed to render. Sorry.
sequenceDiagram;
    autonumber
    participant data
    participant filters
    participant filtered data
    participant teal module
    data->filters: gets
    filters->>filtered data: becomes
    filtered data->>teal module: sent to
"
)

The sequence diagram above illustrates the different stages that data goes through within the teal framework, supported by the teal.slice package:

Data is created and loaded into teal app;
- Data sets are wrapped in a teal_data before being passed to the app;
- The teal_data class facilitates reproducibility;
Data is passed to the filter panel;
- Users (or app developers) can specify filters to apply;
- Filters can be specified globally, for the whole app, or for specific modules;
- Filtering code is appended to the data;
- See the Filter panel vignette for details;
Filtered data is sent to teal modules for analysis;
- Each module receives a teal_data object so analysis code applied to the data is tracked (and can be used to reproduce the whole analysis);

Whenever filters are added or removed, the data coming into modules is re-computed, providing the teal module with new filtered data to conduct the required analysis.