Allow for sub graph support for ie graphviz and graph_phyz

That dot file is the one I always refer to myself :)

One problem with graphviz implementation is one cannot link to a subgraph like a3 ->subgraph cluster_0

A problem for graph_phyz is it cannot know the contents of a subgraph like a3 -> b2

graph.inc and Graph API data structure lack the ability to register a link to a node in a subgraph.

Maybe we can introduce a namespace construct like sub1:a1 to trigger code to dig deeper (recursive) into the graph structure.

As each node has it's internal structure free at will it can contain sub graphs no problem.

Puzzle is the inter graph: do we need absolute path or relative?

a -> b
b:c -> a

leads to structure

[a][links][b]
[b][subgraph][c][links][???a]

Hope this helps a little.

We should read some docs too. Maybe http://en.wikipedia.org/wiki/Graph_theory has some useful ones.

I just realize the above is not correct. Each 'node' must have a unique ID. Indicating it is a part of a subgraph is crap. a subgraph is just a grouping of unique IDs

@s.Daniel can you try do describe how one or more views can provide for your subgraphs?

See also #1396538: Should we merge multiple views outputs into 1 graph? or maybe views grouping could help?

Problem with graphviz is linking to a subgraph. Say node A is a subgraph then it is not available for linking. But node A is a unique ID from Graph API perspective.

IE nodes A, B, C, D, E, F form a network like

digraph {
  subgraph cluster_a {
    label = "cluster_a"
    b
    c
  }

  subgraph cluster_e {
    label = "cluster_e"
    f
  }
  d
  f -> c
  d -> cluster_a
}

disallow for links like d -> cluster_a. But our data-structure is IE

$g['nodes']['A'] = array(...); // properties of node A
$g['nodes']['B'] = array(...); // properties of node B
... more nodes
$g['nodes']['F'] = array(...); // properties of node F

$g['nodes']['A']['subgraph']['nodes']['B'] = TRUE;
$g['nodes']['A']['subgraph']['nodes']['C'] = TRUE;
$g['nodes']['E']['subgraph']['nodes']['F'] = TRUE;

$g['nodes']['D']['links']['A'] = array(); // graphapi_to_dot() should retract this link
$g['nodes']['F']['links']['C'] = array();

The datastructure looks ok to me. We now can express node 'A' is a subgraph containing nodes 'B' and 'C'.

Next we need some primitives/functions to manipulate subgraphs.

// Adds a graph as children of the given node
function graphapi_add_subgraph($g, $node, $sub){};

// Adds a child to the given node
function graphapi_add_child_node($g, $node, $child){};

Note ours data-structure deflates the parent-child tree into a one level deep structure.

The renderer ie graph_phyz or graphviz need to do a topological sort to create their tree nature back.

@s.Daniel What do you think?

I did a first attempt. The graph from #1 should be possible.

But we need a solution for nested subgraphs. No a big deal but it needs some more time.

See

/**
 * Calculate the tree of subgraphs.
 * @return array tree structure of sub graphs
 */
function graphapi_get_graph_tree() {
  // TODO: provide a result
  return array();
}

@s.Daniel please test the current state and please help with the views question from #3

Nice finding: dot lingo : compound = TRUE

That brings us to the settings forms. Through views each graph has overall (graph) settings and node or link settings. So this compound setting should probably set on the graph and maybe node level.

You patch is too big. You prob downloaded a tarball?

You should add a remote to your sandbox I guess git add remote to Graph API.

+++ b/.gitignore
@@ -0,0 +1,2 @@
diff --git a/LICENSE.txt b/LICENSE.txt

Oeps

+++ b/modules/graph_phyz/graph_phyz.module
@@ -170,16 +170,16 @@ function template_preprocess_views_graphapi_style_graph_phyz(&$vars) {
-function theme_graph_phyz_container($variables) {
-  return graph_phyz_container($variables['graph'], $variables['config']);
+function theme_graph_phyz_container($vars) {
+  return graph_phyz_container($vars['graph'], $vars['config']);

Changing a var name ... why?

+++ b/modules/graphviz/graphviz.info
@@ -3,5 +3,6 @@ description = A text implementation of the Graphviz data structure
+dependencies[] = graphviz_filter
 

I'm not sure my dev env works with it :(

I prob should try it now there is a D7 version.

+++ b/modules/graphviz/graphviz.module
@@ -66,15 +57,73 @@ function graphviz_theme() {
+ * ¶
+ * @param type $vars ¶

Whitespace

+++ b/modules/graphviz/graphviz.module
@@ -90,21 +139,28 @@ function theme_graphapi_graphviz_graphapi($vars) {
 function graphviz_to_dot($graph) {

It should receive the $settings too.

The settings should contain the global graph and node and link settings.

I should have fixed this earliers. Sorry.

+++ b/modules/graphviz/graphviz.module
@@ -113,10 +169,19 @@ function graphviz_to_dot($graph) {
+      if (empty($graph[$eid]['_subgraph'])) { // node -> node
+        $dot[] = "  \"node_$id\" -> \"node_$eid\";";
+      } elseif (isset($graph[$eid]['_subgraph'])&& empty($graph[$id]['_subgraph'])) { // node -> subgraph
+        $tnode = $graph[$eid]['_subgraph'][0];
+        $dot[] = "  \"node_$id\" -> \"node_" . $tnode . "\" [lhead=cluster_" . $eid . "];";
+      } elseif (isset($graph[$eid]['_subgraph'])&& isset($graph[$id]['_subgraph'])) { // subgraph -> subgraph
+        $tnode = $graph[$eid]['_subgraph'][0];
+        $lnode = $graph[$id]['_subgraph'][0];
+        $dot[] = "  \"node_$lnode\" -> \"node_" . $tnode . "\" [lhead=cluster_" . $eid . " ltail=cluster_" . $id ."];";

Is this in line with latest version?!?

If you think graphviz_filter is the drupal only implementation we should move over all code over to that project.

But for now we can express each render engine (dot, neato, ... ) as a separate _graphapi_format.

I move this issue to Graphviz project.

See it's Graph Phyz counterpart #1881376: Should we add subgraphs.

Graphviz now has settings in progress.

See /admin/config/system/graphapi/engines/graphviz

I think we should not apply the patch from this issue.

Let's create a few new issues from this one ok?

- graph [fontsize=10 fontname="Verdana" compound=true] can be done through #1881430: Add useful attributes to the project.

The settings from mentioned issue are not yet applied through the theme function.

#7 is done by #1881548: Convert PHP variables to the DOT text format
#10 is covered by #1881430: Add useful attributes to the project.
Original feature is now in #1881552: Add nested subgraphs

So I close this one as this was about sub graph support we now have in small.

Next time we must try to keep the issue on topic a little more. My bad too ;-)

Please open new issues for items I've missed :-)