Allow clients to add more attributes to html output

[clemens-tolboom]

This PR adds

public function createImageObject() {

in order to allow clients to add more attributes to render their graph html like

$domElement = $graphviz->createImageObject();
$domElement->setAttribute('style', 'max-width:100%;');
return $domElement->ownerDocument->saveHtml($domElement);

[clemens-tolboom]

One could argu the client should call createImageSrc instead.

But I prefer an attributes approach.

[clemens-tolboom]

Hmmm ... this is too tricky.

In Drupal I had two groups (1 class and the other 10 classes) of which each image renders 100% width ... that looks bad.

[clemens-tolboom]

I want to merge this today as:

1. There are tests for the change
2. We get test capabilities for Graphviz dot rendering
3. There is no BC problem
4. I need this for Drupal

[clue]

Thanks for the PR! I can perfectly understand where you're coming from and certainly see a need for something like this.

I want to merge this today

Thanks for the heads up. However, I think we should reconsider if we actually want this in this library. We've already discussed moving GraphViz support to a separate project (which I'm not opposed against at all). Also, your changes add a requirement for ext-dom (which is not available on at least one of my installations).

Perhaps it makes sense to remove createImageHtml() altogether? What's your position on that matter?

[clemens-tolboom]

discussed moving GraphViz

Yeah ... we should come up with a good package diagram. What belongs were!

Moving Graphviz out of Graph is a good idea. Puzzle is where to? A new repo? I have no good suggestion for it's new home :-/

requirement for ext-dom

Adding ext-dom to the plate is indeed a nimby dependency for Graph. But for Graphviz we want to add HTML like stuff then ext-dom is not bad IMHO ... I'm working in a test for graph-uml clue/graph-uml#23

remove createImageHtml()

I like the code flow as setFormat decide what the output html should be. So please leave it in.

[clemens-tolboom]

Shall we add the PR apart from the functional changes in

 function createImageHtml()

Then we have the nice createImageObject for CMS clients like Drupal. Or does that break installation on non ext-dom systems?

[clue]

As discussed in #97, GraphViz will be moved to a separate repo (graphp/graphviz) eventually.

As such, this feature doesn't make much sense in this library anymore. I'm inclined to close this ticket, but I'll leave this open for reference until #97 is completed.

[clemens-tolboom]

Let's not loose this PR for graphviz :)

[clue]

As noted above, GraphViz will be split off into a separate repository, see graphp/graphviz#1.

Let's not loose this PR for graphviz :)

I've moved the suggestion over to graphp/graphviz#4, so we can now close this here. Thanks for the suggestion!

[clemens-tolboom]

Hope to find time to revive my PR but afraid not :(