vis_drake_graph tends to get messy with more complex plans, consider allowing visNetwork::visHierachicalLayout set the layout

[strazto]

Prework

• Read and abide by drake's code of conduct.
• Search for duplicates among the existing issues, both open and closed.

Proposal

Presently, vis_drake_graph() tends to get pretty ugly when rendering my plan with the defaults.

I will supply a drake_graph_info() object serialized as yaml, and everything I use to deserialize it to illustrate my example.

Reading the graph

dep_graph_map_handler <- function(x){
  for (nm in c("nodes", "edges", "legend_nodes")){
    if (nm %in% names(x)) x[[nm]] %<>% tibble::as_tibble()
  }
  x
}

#' @export
read_graph_info_yaml <- function(
  path, 
  grouping_col = "cluster_id", 
  grouping_col_truncated = "set"
  ) {
  g <- glue::glue
  
  graph_info <- path %>%
    yaml::read_yaml(handlers = list(map = dep_graph_map_handler))
  
  if (!is.na(grouping_col)) {
    graph_info$nodes$label %<>% 
      stringr::str_replace(
        g("{grouping_col}:"), 
        g("{grouping_col_truncated}:")
        )
  }
  
  graph_info
}

### My render of the graph

#' @export
custom_render_dependency_graph <- function(graph_info, metadata = NULL, ...) {

  out <- graph_info %>% 
    drake::render_drake_graph(on_select = TRUE, ncol_legend = 0, ...) %>% 
    visNetwork::visHierarchicalLayout(direction = "LR", levelSeparation = 250) %>%
    visNetwork::visEdges(smooth = list(type = "cubicBezier", forceDirection = "horizontal"))

  # ... There was more to this but I'll spare you as it's irrelevant
  out
}

### Default Render of the graph

graph_info <- read_graph_info_yaml("dependency_graph_yaml.txt")

out_default <- graph_info %>% 
  drake::render_drake_graph(
    on_select = TRUE, 
    ncol_legend = 0, 
    width = "100%", 
    height = "1080px"
  ) 

out_custom <- graph_info %>% 


  custom_render_dependency_graph(
    width = "100%", 
    height = "1080px"
  )

visNetwork::visSave(out_default, file = "out_default.html")
visNetwork::visSave(out_custom, file = "out_custom.html")

The serialized dependency graph:

dependency_graph_yaml.txt

The outputs:

The custom-formatted dep graph

out_custom.html.txt

The default-formatted dep graph

out_default.html.txt

What's actually been changed?

The (dramatic) changes between these formats come from deferring to visNetwork's hierachical formatting functions:

 graph_info %>% 
    drake::render_drake_graph(on_select = TRUE, ncol_legend = 0, ...)  
    visNetwork::visHierarchicalLayout(direction = "LR", levelSeparation = 250) %>%
    visNetwork::visEdges(smooth = list(type = "cubicBezier", forceDirection = "horizontal"))

Rather than letting drake position the nodes itself, which does work for smaller graphs, but not for mine.

I'm aware that as reprex's go, this could be more self-contained, but my dataset is the prime example for which I knew I could show these results.

[wlandau]

That's so awesome! I had considered the default hierarchical layout before, but it was generating graphs with reversed edges. I had no idea about forceDirection. That's the piece we needed all along. Thank you so much! Let's absolutely do this.

[wlandau]

Now implemented. Give 2f54d21 a try.

[strazto]

So excited!
It's always nice to mainline my in-house tweaks and declutter my codebase.