inst/shiny/v1.3/gene_expression/obj_projection_selected_cells.R

In romanhaa/cerebroApp: Interactive visualization of scRNA-seq data with Cerebro

##----------------------------------------------------------------------------##
## Reactive that holds IDs of selected cells (ID is built from position in
## projection).
##----------------------------------------------------------------------------##
expression_projection_selected_cells <- reactive({
  ## make sure plot parameters are set because it means that the plot can be
  ## generated
  req(
    expression_projection_parameters_plot(),
    expression_projection_data()
  )
  # message('--> trigger "expression_projection_selected_cells"')
  ## check selection
  ## ... selection has not been made or there is no cell in it
  if (
    is.null(plotly::event_data("plotly_selected", source = "expression_projection")) ||
    length(plotly::event_data("plotly_selected", source = "expression_projection")) == 0
  ) {
    return(NULL)
  ## ... selection has been made and at least 1 cell is in it
  } else {
    ## get number of selected cells
    selected_cells <- plotly::event_data("plotly_selected", source = "expression_projection") %>%
      dplyr::mutate(identifier = paste0(x, '-', y))
    # message(str(selected_cells))
    return(selected_cells)
  }
})