Theme doesn't apply when using components

[birdsarah]

Can't get themes to apply when using bokeh.embed.components.

Have tried manually using theme.apply_to_model(model), but it doesn't seem to work.

[birdsarah]

ping @bryevdv - any thoughts

[bryevdv]

Not offhand, I have a vague recollection of seeing this now, so thanks for capturing the issue.

[postelrich]

Ran into the same or similar issue trying to set the theme of the curdoc when outputting to a notebook.

from bokeh.io import cur_doc, show, output_notebook
from bokeh.themes import Theme

curdoc().theme = Theme(json={'attrs': {'Title': {'text_color': 'pink'}}})

[djpugh]

I've hit this too, and it looks like it is because components uses a

with _ModelInDocument:

Which adds the model to a document, which combined with _attach_document in model.py applies the document theme and then the default theme if it is removed. It seems to work if you add the model to a document before calling components:

p = figure()
curdoc().theme = Theme(json={'attrs': {'Title': {'text_color': 'pink'}}})
cudoc().add_root(p)
script, div = components(p)

@bryevdv - I'm happy to look at a fix, I guess the obvious one would be to do something to preserve the theme in the with _ModelInDocument: call even if the model is not in a document

[djpugh]

Something like:

class _ModelInDocument(object):
    # 'models' can be a single Model, a single Document, or a list of either
    def __init__(self, models):
        from .document import Document
        self._to_remove_after = []
        self._theme = []
        if not isinstance(models, list):
            models = [models]

        self._doc = _find_some_document(models)
        if self._doc is None:
            # oh well - just make up a doc
            self._doc = Document()

        for model in models:
            if isinstance(model, Model):
                if model.document is None:
                    # Gets the model theme (or None if no theme)
                    self._theme.append(model.themed_values())
                    self._to_remove_after.append(model)

    def __exit__(self, type, value, traceback):
        for i, model in enumerate(self._to_remove_after):
            model.document.remove_root(model)
            if self._theme[i] is not None:
                # Applies the model theme after removing the document
                model.apply_theme(self._theme[i])

    def __enter__(self):
        for i, model in enumerate(self._to_remove_after):
            # This should preserve model theming here
            self._doc.add_root(model)
            if self._theme[i] is not None:
                # Applies the model theme after adding the document
                model.apply_theme(self._theme[i])

But I'm not sure if this would have repercussions elsewhere - otherwise this could be done around the with loop in embed.py.