The documentation for "headport" and "tailport" says that it Indicates where on the head/tail node to attach the head/tail of the edge. In the default case, the edge is aimed towards the center of the node, and then clipped at the node boundary.
The code given below -
`digraph {
rankdir=LR;
node [ shape=record ];

struct1 [
label = "a|b|<port1> c";
];
struct2 [
label = "a|{ <port2> b1|b2}|c";
];
struct1->struct2 [ label="xyz", headport="port1", tailport="port2" ];
}`
should generate an edge from node:struct1 port "c" to node:struct2 port "b1" like this -

however it generates an edge like this , using default behavior.

I understand that struct1:port1 -> struct2:port2 [ label="xyz" ]; can be used for the purpose ,but I don't know how to use addEdge method to generate such a dot string (open to suggestions ).

I request you to please help me out , to generate an edge like in image 1.
I have also tried other versions of port attribute argument such as such , "c","port0:c" etc yet no use.

I try to change the class of the edges in the rendered SVG. So I pass the class property as attribute.

After that, the error TypeError: Cannot read property 'type' of undefined occurs in the mustBeQuoted function (graphviz\lib\deps\attributs.js:191:42)

Reason is that class attribute is not implemented in attributs.js (graphviz\lib\deps\attributs.js)

var attrs = {
  "Damping" :            { "usage" : "G",    "type" : "double" },
  "K" :                  { "usage" : "GC",   "type" : "double" },
  "URL" :                { "usage" : "ENGC", "type" : "escString" },
  "area" :               { "usage" : "NC",   "type" : "double" },
  "arrowhead" :          { "usage" : "E",    "type" : "arrowType" },
  "arrowsize" :          { "usage" : "E",    "type" : "double" },
  "arrowtail" :          { "usage" : "E",    "type" : "arrowType" },
  "aspect" :             { "usage" : "G",    "type" : "aspectType" },
  "bb" :                 { "usage" : "G",    "type" : "rect" },
  "bgcolor" :            { "usage" : "GC",   "type" : "color" },
  "center" :             { "usage" : "G",    "type" : "bool" },
  "charset" :            { "usage" : "G",    "type" : "string" },
  "clusterrank" :        { "usage" : "G",    "type" : "clusterMode" },
  "color" :              { "usage" : "ENC",  "type" : "color" },
  "colorscheme" :        { "usage" : "ENCG", "type" : "string" },
...

Is it possible to add class attribute as feature?

After I finished install of Graphviz app & npm package of node-graphviz,,
when I type this command "node hello_world.js" at Mac terminal, I've noticed under error message.

I use Graphviz ver 1.13 , node.js ver 0.3.1, npm ver 0.2.10-1.

If you know how to solve this error, tell me solution, please.

node.js:50
throw e; // process.nextTick error, or 'error' event on first tick
^
Error: EPIPE, Broken pipe
at Stream._writeImpl (net.js:139:14)
at Stream._writeOut (net.js:558:25)
at Stream.write (net.js:491:17)
at [object Object].render (/usr/local/lib/node/.npm/graphviz/0.0.3/package/lib/deps/graph.js:330:18)
at [object Object].output (/usr/local/lib/node/.npm/graphviz/0.0.3/package/lib/deps/graph.js:335:8)
at Object. (/Users/user/Documents/workspace/testNodeJS/graphviz-0.0.3/tests/hello_world.js:20:3)
at Module._compile (node.js:329:23)
at Object..js (node.js:337:12)
at Module.load (node.js:260:25)

at Array. (node.js:351:24)

a6ea928

Fixes graphviz.parse() but hasn't been pushed to npm.

I want to remove duplicate edges. I need to set the graph strict. How to do that ?

I can't seem to find imagepos for nodes.
I manually updated my Attributes.js file and it appears to work fine.
This will position the image in the node where you would like it.
Options are as follows;

• tl | Top Left
• tc | Top Centered
• tr | Top Right
• ml | Middle Left
• mc | Middle Centered (the default)
• mr | Middle Right
• bl | Bottom Left
• bc | Bottom Centered
• br | Bottom Right

"imagepos" : { "usage" : "N", "type" : "string" }

Reference: https://www.graphviz.org/doc/info/attrs.html#d:height

Thanks,

I have some code which ends up creating duplicate edges because I can't figure out how to check if an exact same edge already exists.

Is there a way by which I can tell this library to simply ignore duplicate edges?

For example: https://github.com/hpcc-systems/hpcc-js-wasm

Disclaimer - I am a contributor to the above project (and can answer any questions)...

On npmjs, the package is reported as GPL-3.0 (see https://www.npmjs.com/package/graphviz)

From the history, the package.json is fixed, but without updating the version number (and without publishing to NPM?)
(see 162db2c)

Please publish a new version to NPM with the fixed license information.

Thanks,
Sven

line 222 of lib/deps/graph.js you have Graph.prototype.getNodeAttribut, I believe it should be Graph.prototype.getEdgeAttribut. Keep up the good work.

Graphviz _parse on data event calls eval(data) each time the event occurs instead of just appending the data and calling eval on the exit event.

I would like to express "{rank=same; node1 node2}", but could not find any sample.
Is it possible to do this with node-graphviz?

Thank you.

I think you need to release the last changes in the repository, in the current code there is a removeNode function on the graph object but the npm version is missing that feature

The attribute 'newrank' is missing in the list of available attributes.

"newrank" : { "usage" : "G", "type" : "bool" },

And it would be great to get an error message like:
Error: The attribute 'newrank' is not support.
or something like this.

This might be just an issue I have come across, but it appears that dox no longer supports generating documentation from a list of files or directories but instead operates only over stdio. I'm working on fixing Jakefile.js to use dox properly, but if you know why this doesn't build I would be greatly appreciative!

Dot specification has HTML-like labels.

They are generally like:
label=<<FONT POINT-SIZE='12'>Some Text</FONT>>

The issue is that Graphviz doesn't understand it if that html label is quoted like this:
label="<<FONT POINT-SIZE='12'>Some Text</FONT>>"

In the attributes js file, lbl is of type lblString, which means it would be quoted.
https://github.com/glejeune/node-graphviz/blob/master/lib/deps/attributs.js#L59

We need a way to say if our label is a string or an html markup. Based on that it must be quoted or not.

I don't know what would be an elegant solution to this.

Any fixes (or even ideas) would be awesome?

@glejeune , would you be able to push a new version to npm please? thanks!

The license field in the package.json says this module is licensed under the GPL v3 but there's an MIT LICENSE file in the root of the repo.

Can you clarify the license of this module and update one or the other location?

Thanks!

P.S. It would be wonderful if this were licensed as MIT :)

Using Graph.render, there are some race conditions with graphviz.on("exit", …), where exit fires before the graphviz.stdout is ended.

So instead of using exit, you can use close in node 0.8. So a solution would be, in graph.js:373

  var version = process.version.split('.')[1]
  graphviz.on(version < 8 ? 'exit' : 'close', function(code) {
  // ...
  });

With #32 my understanding is that the valid license is MIT. However in this file (https://github.com/glejeune/node-graphviz/blob/master/lib/ext/gvpr/dot2js.g) there is still a GPL license referenced. Can that be removed as well?

Hi @glejeune,

trying to use your library with my vscode extension. Problem, the super weird Array hashmap stuff is breaking as the for(var name in this.attributs.items) { will not only return added items but also functionnames. no clue why this does not happen on the console but breaks in vscode (maybe more strict?) but the usage feels a bit strange anyway.

I quickly checked the open PR's and #23 appears to solve that problem with an hasOwnProperty check. I guess there are likely more people having the same issues. #23 is a hack but will probably fix the problem as a short-term solution. Any thoughts on merging it? Otherwise I'll have to switch to a different lib.

TypeError: Cannot read property 'type' of undefined
soljson.js:28
at mustBeQuoted (node_modules/surya/node_modules/graphviz/lib/deps/attributs.js:190:42)
at quoteMe (node_modules/surya/node_modules/graphviz/lib/deps/attributs.js:194:6)
at exports.Attributs.Attributs.to_dot (node_modules/surya/node_modules/graphviz/lib/deps/attributs.js:241:56)
at exports.Graph.Graph.to_dot (node_modules/surya/node_modules/graphviz/lib/deps/graph.js:249:61)
at Object.graph (node_modules/surya/lib/graph.js:462:63)
at Commands.surya (src/features/commands.js:53:29)
at src/extension.js:625:30

it is undefined because the in op returned GetEnumerator which is an array method and not an item. see screenshot. left side contents of the hash-array-thing, right side tooltip contents of name (GetEnumerator). this will later break in mustBeQuoted as GetEnumerator is no valid attrib (was never set by our code).

cheers,
tin

This inst really an issue, but more of a question. How do I get the coordinates of a node? I am using the example provided, but have not been able to find where/if the coordinates are stored.

I explored the graph object but such attributes do not seem to be there.

// Print the dot script
console.log( g.to_dot() );

console.log(g); // There does not seem to be any such info in this object, nor is there any info on an individual node.

Any help on this would be much appreciated. Thank you.

Hi,

This is a great Node module for Graphviz diagrams. Unfortunately this can't work in browsers because graphviz isn't available. But what if we could have a browser friendly stripped down version that generates dot code string.
And then I can use https://github.com/mdaines/viz.js to greate diagrams with that dot code in browsers without Node.JS.
Since the author understands his code best, I am requesting you if you can please create a stripped down version that just generates dot code?
Thanks...

Hi,

I tried setting href attribute for nodes like this:

node.set( 'href', 'http://google.com');

but I am getting the following error:

DEBUG: Warning : Invalid attribut `href' for a node

How can we have clickable nodes?