def _renew_images(self, driver=None):
"""Renew thumbnail and deep zoom images.
Parameters
----------
driver
selenium webdriver instance, if not given
a firefox instance is created using
`utils.get_firefox_webdriver()`
Returns
-------
None
"""
plot = self.get_plot(thumbnail=True)
#
# Create a plot and save a thumbnail image in in-memory file
#
generate_driver = not driver
if generate_driver:
driver = webdriver_control.create()
driver.implicitly_wait(1200)
try:
image = get_screenshot_as_png(plot, driver=driver, timeout=20)
thumbnail_height = 400
thumbnail_width = int(image.size[0] * thumbnail_height / image.size[1])
image.thumbnail((thumbnail_width, thumbnail_height))
image_file = io.BytesIO()
image.save(image_file, 'PNG')
#
# Remove old thumbnail
#
self.thumbnail.delete()
#
# Save the contents of in-memory file in Django image field
#
self.thumbnail.save(
f'{self.id}/thumbnail.png',
ContentFile(image_file.getvalue()),
)
except RuntimeError as exc:
_log.error(f"Cannot generate thumbnail for topography {self.id}. Reason: {exc}")
self.thumbnail.delete()
_log.warning(f"Thumbnail generation failed for topography {self.id}. Deleted old thumbnail which could be outdated.")
if generate_driver:
driver.close() # important to free memory
if self.size_y is not None:
# This is a topography (map), we need to create a Deep Zoom Image
make_dzi(self.topography(), user_directory_path(self, f'{self.id}/dzi'))
def save_png(model, filename):
"""
Saves a bokeh model to png
Arguments
---------
model: bokeh.model.Model
Model to save to png
filename: str
Filename to save to
"""
from bokeh.io.webdriver import webdriver_control
if not state.webdriver:
state.webdriver = webdriver_control.create()
webdriver = state.webdriver
export_png(model, filename=filename, webdriver=webdriver)
def save_png(model, filename, template=None, template_variables=None):
"""
Saves a bokeh model to png
Arguments
---------
model: bokeh.model.Model
Model to save to png
filename: str
Filename to save to
template:
template file, as used by bokeh.file_html. If None will use bokeh defaults
template_variables:
template_variables file dict, as used by bokeh.file_html
"""
from bokeh.io.webdriver import webdriver_control
if not state.webdriver:
state.webdriver = webdriver_control.create()
webdriver = state.webdriver
try:
if template:
def get_layout_html(obj, resources, width, height):
return file_html(obj,
resources,
title="",
template=template,
template_variables=template_variables,
suppress_callback_warning=True,
_always_new=True)
old_layout_fn = bokeh.io.export.get_layout_html
bokeh.io.export.get_layout_html = get_layout_html
export_png(model, filename=filename, webdriver=webdriver)
except Exception:
raise
finally:
if template:
bokeh.io.export.get_layout_html = old_layout_fn
def webdriver():
driver = webdriver_control.create()
yield driver
terminate_webdriver(driver)
def webdriver(request):
driver = webdriver_control.create(request.param)
try:
yield driver
finally:
webdriver_control.terminate(driver)
def webdriver():
driver = webdriver_control.create()
yield driver
terminate_webdriver(driver)
def save_png(model,
filename,
resources=CDN,
template=None,
template_variables=None,
timeout=5):
"""
Saves a bokeh model to png
Arguments
---------
model: bokeh.model.Model
Model to save to png
filename: str
Filename to save to
template:
template file, as used by bokeh.file_html. If None will use bokeh defaults
template_variables:
template_variables file dict, as used by bokeh.file_html
timeout: int
The maximum amount of time (in seconds) to wait for
"""
from bokeh.io.webdriver import webdriver_control
if not state.webdriver:
state.webdriver = webdriver_control.create()
webdriver = state.webdriver
if template is None:
template = r"""\
{% block preamble %}
<style>
html, body {
box-sizing: border-box;
width: 100%;
height: 100%;
margin: 0;
border: 0;
padding: 0;
overflow: hidden;
}
</style>
{% endblock %}
"""
try:
def get_layout_html(obj, resources, width, height, **kwargs):
resources = Resources.from_bokeh(resources)
return file_html(obj,
resources,
title="",
template=template,
template_variables=template_variables or {},
_always_new=True)
old_layout_fn = bokeh.io.export.get_layout_html
bokeh.io.export.get_layout_html = get_layout_html
img = get_screenshot_as_png(model,
driver=webdriver,
timeout=timeout,
resources=resources)
if img.width == 0 or img.height == 0:
raise ValueError("unable to save an empty image")
img.save(filename, format="png")
except Exception:
raise
finally:
if template:
bokeh.io.export.get_layout_html = old_layout_fn
def _figure_data(self, plot, fmt, doc=None, as_script=False, **kwargs):
"""
Given a plot instance, an output format and an optional bokeh
document, return the corresponding data. If as_script is True,
the content will be split in an HTML and a JS component.
"""
model = plot.state
if doc is None:
doc = plot.document
else:
plot.document = doc
for m in model.references():
m._document = None
doc.theme = self.theme
doc.add_root(model)
# Bokeh raises warnings about duplicate tools and empty subplots
# but at the holoviews level these are not issues
logger = logging.getLogger(bokeh.core.validation.check.__file__)
logger.disabled = True
data = None
if fmt == 'gif':
from bokeh.io.export import get_screenshot_as_png
from bokeh.io.webdriver import webdriver_control
if state.webdriver is None:
webdriver = webdriver_control.create()
else:
webdriver = state.webdriver
nframes = len(plot)
frames = []
for i in range(nframes):
plot.update(i)
img = get_screenshot_as_png(plot.state, driver=webdriver)
frames.append(img)
if state.webdriver is not None:
webdriver.close()
bio = BytesIO()
duration = (1. / self.fps) * 1000
frames[0].save(bio,
format='GIF',
append_images=frames[1:],
save_all=True,
duration=duration,
loop=0)
bio.seek(0)
data = bio.read()
elif fmt == 'png':
from bokeh.io.export import get_screenshot_as_png
img = get_screenshot_as_png(plot.state, driver=state.webdriver)
imgByteArr = BytesIO()
img.save(imgByteArr, format='PNG')
data = imgByteArr.getvalue()
else:
div = render_mimebundle(plot.state, doc, plot.comm)[0]['text/html']
if as_script and fmt in ['png', 'gif']:
b64 = base64.b64encode(data).decode("utf-8")
(mime_type, tag) = MIME_TYPES[fmt], HTML_TAGS[fmt]
src = HTML_TAGS['base64'].format(mime_type=mime_type, b64=b64)
div = tag.format(src=src, mime_type=mime_type, css='')
plot.document = doc
if as_script or data is None:
return div
else:
return data
