On_init in js callback

Community Support
1

Hi - I have been trying to find out if can inject some JS code that can run on initialization of a specific component or on initialization of the bokeh app or something…basically something that triggers when a component or all components have loaded?

2

Not yet, it seems: Hook for callback upon document init · Issue #4272 · bokeh/bokeh · GitHub
But maybe my example from that issue will work for you.

1 Like
3

Is your work around for bokeh serve or can it also be used for customJS?

I am using customJS

4

The answer is right there at the end of my post at Hook for callback upon document init · Issue #4272 · bokeh/bokeh · GitHub

5

aha ok nice…will it also work when using json_item instead of save/show ?

6

I don’t know.

7

I get this error when i try to run your full example with the only change that i use json_item instead of save:

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-107-4f70c56c7c2f> in <module>
     82 
     83 layout = column(slider, plot)
---> 84 json_item([idle_doc_observer, layout])

~/anaconda3/lib/python3.7/site-packages/bokeh/embed/standalone.py in json_item(model, target, theme)
    366 
    367     '''
--> 368     with OutputDocumentFor([model], apply_theme=theme) as doc:
    369         doc.title = ""
    370         docs_json = standalone_docs_json([model])

~/anaconda3/lib/python3.7/contextlib.py in __enter__(self)
    110         del self.args, self.kwds, self.func
    111         try:
--> 112             return next(self.gen)
    113         except StopIteration:
    114             raise RuntimeError("generator didn't yield") from None

~/anaconda3/lib/python3.7/site-packages/bokeh/embed/util.py in OutputDocumentFor(objs, apply_theme, always_new)
    116 
    117     if not isinstance(objs, Sequence) or len(objs) == 0 or not all(isinstance(x, Model) for x in objs):
--> 118         raise ValueError("OutputDocumentFor expects a sequence of Models")
    119 
    120     def finish(): pass

ValueError: OutputDocumentFor expects a sequence of Models

Do you know how this could be fixed?

8

According to the docstring of json_item, it expects a single model and not a list of models.

Given that the implementation of json_item is just 6 lines, I would just copy it and modify it to my needs in my own code so it can receive a list of models.

9

ok yes…that makes sense…i did that, and I am getting this javascript error now:

Error: Model 'IdleDocObserver' does not exist. This could be due to a widget or a custom model not being registered before first usage.
    at Object.s.Models (bokeh-2.0.0.min.js:149)
    at Function._instantiate_object (bokeh-2.0.0.min.js:148)
    at Function._instantiate_references_json (bokeh-2.0.0.min.js:148)
    at Function.from_json (bokeh-2.0.0.min.js:148)
    at g (bokeh-2.0.0.min.js:146)
    at bokeh-2.0.0.min.js:146
    at bokeh-2.0.0.min.js:171

Any idea why i am getting that?

10

My code looks like this:

        all_plots = column(row(...)) //truncated
        models = [idle_doc_observer, all_plots]
        with OutputDocumentFor(models) as doc:
            doc.title = ""
            docs_json = standalone_docs_json(models)

        doc = list(docs_json.values())[0]
        root_id = doc['roots']['root_ids'][0]

        return {
            'target_id' : 'my_plot',
            'root_id'   : root_id,
            'doc'       : doc,
        }

is that not correct?

11

Here my experience ends. You may want to look at how file_html works, especially the call to bundle_for_objs_and_resources since that’s the function that compiles all custom models.
Feel free to also open an feature request on GitHub for this.

12

Custom models are not currently supported with json_item