Merge pull request #627 from bnmajor/defer-codec-registration

Defer codec registration

Author: thewtex

docs/conf.py

@@ -39,7 +39,8 @@
 extensions = ['myst_parser',]
 
 html_theme_options = dict(
-    github_url='https://github.com/InsightSoftwareConsortium/itkwidgets'
+    github_url='https://github.com/InsightSoftwareConsortium/itkwidgets',
+    icon_links=[],
 )
 
 # jupyterlite_config = jupyterlite_dir / "jupyterlite_config.json"

itkwidgets/__init__.py

@@ -1,11 +1,5 @@
 """itkwidgets: Interactive widgets to visualize images, point sets, and 3D geometry on the web."""
 
-from imjoy_rpc import register_default_codecs
-register_default_codecs()
-
-from .imjoy import register_itkwasm_imjoy_codecs
-register_itkwasm_imjoy_codecs()
-
 from .viewer import Viewer, view
 
 __all__ = [

itkwidgets/viewer.py

@@ -11,10 +11,12 @@
 from ._type_aliases import Gaussians, Style, Image, PointSet
 from ._initialization_params import init_params_dict
 from ._method_types import deferred_methods
+from .imjoy import register_itkwasm_imjoy_codecs
 from .integrations import _detect_render_type, _get_viewer_image, _get_viewer_point_set
 from .integrations.environment import ENVIRONMENT, Env
 from .render_types import RenderType
 from .viewer_config import ITK_VIEWER_SRC, PYDATA_SPHINX_HREF, MUI_HREF
+from imjoy_rpc import register_default_codecs
 
 __all__ = [
     "Viewer",
@@ -31,7 +33,14 @@ class ViewerRPC:
     def __init__(
         self, ui_collapsed=True, rotate=False, ui="pydata-sphinx", data=None
     ):
+        global _codecs_registered
         """Create a viewer."""
+        # Register codecs if they haven't been already
+        if not _codecs_registered:
+            register_default_codecs()
+            register_itkwasm_imjoy_codecs()
+            _codecs_registered = True
+
         self._init_viewer_kwargs = dict(ui_collapsed=ui_collapsed, rotate=rotate, ui=ui)
         self.init_data = data
         self.img = display(HTML(f'<div />'), display_id=str(uuid.uuid4()))