Merge pull request #3 from CodeForPhilly/251_add_pdf_export_bufferd

251 add pdf export bufferd [WIP]

Author: Zedmor

requirements.txt

@@ -7,3 +7,5 @@ dash
 dash_bootstrap_components
 pyyaml
 gunicorn
+percy
+selenium

src/__init__.py

@@ -14,7 +14,6 @@
 from chime_dash.app.components.base import Component, HTMLComponentError
 from dash_bootstrap_components.themes import BOOTSTRAP
 
-from chime_dash.app.components.location import LocationComponent
 from chime_dash.app.components.navbar import Navbar
 from chime_dash.app.components.container import Container
 
@@ -32,9 +31,7 @@ def __init__(self, language, defaults):
         """
         super().__init__(language, defaults)
         self.components = OrderedDict(
-            navbar=Navbar(language, defaults),
-            container=Container(language, defaults),
-            location=LocationComponent()
+            navbar=Navbar(language, defaults), container=Container(language, defaults),
         )
         self.callback_outputs = []
         self.callback_inputs = OrderedDict()

src/chime_dash/app/components/__init__.py

@@ -1,14 +1,13 @@
 """Initializes the  dash html
 """
 from collections import OrderedDict
-from copy import deepcopy
 
 import dash_bootstrap_components as dbc
-import dash_core_components as dcc
+
 from chime_dash.app.components.base import Component, HTMLComponentError
 from chime_dash.app.components.content import Content
 from chime_dash.app.components.sidebar import Sidebar
-from chime_dash.app.services.pdf_printer import print_to_pdf
+
 from penn_chime.models import SimSirModel
 
 
@@ -22,8 +21,7 @@ def __init__(self, language, defaults):
         super().__init__(language, defaults)
         self.pdf_filename = None
         self.components = OrderedDict(
-            sidebar=Sidebar(language, defaults),
-            content=Content(language, defaults),
+            sidebar=Sidebar(language, defaults), content=Content(language, defaults),
         )
         self.callback_outputs = []
         self.callback_inputs = OrderedDict()
@@ -35,7 +33,9 @@ def get_html(self):
         """Initializes the content container dash html
         """
         container = dbc.Container(
-            children=dbc.Row(self.components["sidebar"].html + self.components["content"].html),
+            children=dbc.Row(
+                self.components["sidebar"].html + self.components["content"].html
+            ),
             fluid=True,
             className="mt-5",
         )
@@ -49,12 +49,6 @@ def callback(self, *args, **kwargs):
         kwargs["model"] = SimSirModel(pars)
         kwargs["pars"] = pars
 
-        save_to_pdf = self.components["sidebar"].save_to_pdf(kwargs)
-        if save_to_pdf:
-            self.pdf_filename = print_to_pdf(deepcopy(self.components['content']), kwargs)
-
-        kwargs['pdf_url'] = self.pdf_filename
-
         callback_returns = []
         for component in self.components.values():
             try:

src/chime_dash/app/components/container.py

@@ -3,28 +3,37 @@
 
 #! _INPUTS should be considered for moving else where
 """
-import dash_html_components as dhc
-
 from typing import List, Dict, Any, Tuple
 from collections import OrderedDict
 
 from dash.dependencies import Input as CallbackInput, Output
 from dash.development.base_component import ComponentMeta
-from dash_html_components import Br
+from dash_html_components import Br, Div, Nav
 
 from penn_chime.defaults import RateLos
 from penn_chime.parameters import Parameters
 
 from chime_dash.app.components.base import Component
-from chime_dash.app.utils.templates import create_switch_input, create_number_input, create_header, create_button, \
-    create_link
+from chime_dash.app.utils.templates import (
+    create_switch_input,
+    create_number_input,
+    create_header,
+    create_button,
+    create_link,
+)
 
 FLOAT_INPUT_MIN = 0.001
 FLOAT_INPUT_STEP = "any"
 
 _INPUTS = OrderedDict(
     regional_parameters={"type": "header", "size": "h3"},
-    market_share={"type": "number", "min": FLOAT_INPUT_MIN, "step": FLOAT_INPUT_STEP, "max": 100.0, "percent": True},
+    market_share={
+        "type": "number",
+        "min": FLOAT_INPUT_MIN,
+        "step": FLOAT_INPUT_STEP,
+        "max": 100.0,
+        "percent": True,
+    },
     susceptible={"type": "number", "min": 1, "step": 1},
     known_infected={"type": "number", "min": 0, "step": 1},
     current_hospitalized={"type": "number", "min": 0, "step": 1},
@@ -50,7 +59,7 @@
         "min": 0.0,
         "step": FLOAT_INPUT_STEP,
         "max": 100.0,
-        "percent": True
+        "percent": True,
     },
     ventilated_rate={
         "type": "number",
@@ -69,8 +78,7 @@
     show_tables={"type": "switch", "value": False},
     show_tool_details={"type": "switch", "value": False},
     show_additional_projections={"type": "switch", "value": False},
-    save_as_pdf={"type": "button", "property": "n_clicks"},
-    pdf_file_link={"type": "link", "property": "href"}
+    download_as_pdf_link={"type": "link"},
 )
 
 
@@ -79,20 +87,27 @@ class Sidebar(Component):
     contains the various inputs used to interact
     with the model.
     """
+
     # localization temp. for widget descriptions
     localization_file = "sidebar.yml"
 
     callback_inputs = OrderedDict(
-        (key, CallbackInput(component_id=key, component_property=_INPUTS[key].get("property", "value")))
-        for key in _INPUTS if _INPUTS[key]["type"] not in ("header", "link")
+        (
+            key,
+            CallbackInput(
+                component_id=key,
+                component_property=_INPUTS[key].get("property", "value"),
+            ),
+        )
+        for key in _INPUTS
+        if _INPUTS[key]["type"] not in ("header", "link")
     )
 
-    callback_outputs = [Output(component_id='pdf_file_link', component_property='href'),
-                        Output(component_id='pdf_file_link', component_property='children')]
+    callback_outputs = [
+        Output(component_id="download_as_pdf_link", component_property="href")
+    ]
 
     def __init__(self, *args, **kwargs):
-        self._save_to_pdf = False
-        self.pdf_button_clicks = 0
         super().__init__(*args, **kwargs)
 
     @staticmethod
@@ -135,7 +150,7 @@ def get_html(self) -> List[ComponentMeta]:
                 element = create_button(idx, self.content)
             elif data["type"] == "link":
                 elements.append(Br())
-                element = create_link(idx)
+                element = create_link(idx, self.content)
             else:
                 raise ValueError(
                     "Failed to parse input '{idx}' with data '{data}'".format(
@@ -144,14 +159,11 @@ def get_html(self) -> List[ComponentMeta]:
                 )
             elements.append(element)
 
-        sidebar = dhc.Nav(
-            children=dhc.Div(
+        sidebar = Nav(
+            children=Div(
                 children=elements,
                 className="p-4",
-                style={
-                    "height": "calc(100vh - 48px)",
-                    "overflowY": "auto",
-                },
+                style={"height": "calc(100vh - 48px)", "overflowY": "auto",},
             ),
             className="col-md-3",
             style={
@@ -160,23 +172,22 @@ def get_html(self) -> List[ComponentMeta]:
                 "bottom": 0,
                 "left": 0,
                 "zIndex": 100,
-                "boxShadow": "inset -1px 0 0 rgba(0, 0, 0, .1)"
-            }
+                "boxShadow": "inset -1px 0 0 rgba(0, 0, 0, .1)",
+            },
         )
 
         return [sidebar]
 
-    def save_to_pdf(self, kwargs):
-        """
-        Return status of save to pdf flag and set it off.
-        """
-        if kwargs.get('save_as_pdf', 0) and kwargs.get('save_as_pdf', 0) > self.pdf_button_clicks:
-            self.pdf_button_clicks = kwargs.get('save_as_pdf', '0')
-            return True
-        return False
-
     def callback(  # pylint: disable=W0613, R0201
         self, *args, **kwargs
     ) -> List[Dict[str, Any]]:
-        return [kwargs.get('pdf_url', ''),
-                self.content['download_report'] if kwargs.get('pdf_url', None) else None]
+
+        url = "/download-as-pdf?" + "&".join(
+            [
+                "{key}={val}".format(key=key, val=val)
+                for key, val in kwargs.items()
+                if not key in ["model", "pars"] and val is not None
+            ]
+        )
+
+        return [url]

src/chime_dash/app/components/location.py

@@ -1,74 +1,74 @@
+"""Utilities for exporting dash app to pdf
+"""
 import json
 import base64
+
 from time import sleep
 
+from io import BytesIO
+
 from dash import Dash
 from dash.testing.application_runners import ThreadedRunner
 from dash.testing.composite import DashComposite
-from dash.dependencies import Input
 from dash_bootstrap_components.themes import BOOTSTRAP
-
-import dash_core_components as dcc
-import uuid
 import dash_bootstrap_components as dbc
 
-from chime_dash.app.utils.templates import UPLOAD_DIRECTORY
-from dash_html_components import Div
 from selenium import webdriver
 
 
-def send_devtools(driver, cmd, params={}):
-  resource = "/session/%s/chromium/send_command_and_get_result" % driver.session_id
-  url = driver.command_executor._url + resource
-  body = json.dumps({'cmd': cmd, 'params': params})
-  response = driver.command_executor._request('POST', url, body)
-  if response['status']:
-    raise Exception(response.get('value'))
-  return response.get('value')
+def send_devtools(driver, cmd, params=None):
+    params = params or None
+    resource = "/session/%s/chromium/send_command_and_get_result" % driver.session_id
+    url = driver.command_executor._url + resource
+    body = json.dumps({"cmd": cmd, "params": params})
+    response = driver.command_executor._request("POST", url, body)
+    if response.get("status", False):
+        raise Exception(response.get("value"))
+    return response.get("value")
 
 
-def save_as_pdf(driver, path, options={}):
-  # https://timvdlippe.github.io/devtools-protocol/tot/Page#method-printToPDF
-  result = send_devtools(driver, "Page.printToPDF", options)
-  with open(path, 'wb') as file:
-    file.write(base64.b64decode(result['data']))
+def save_as_pdf(driver, options=None):
+    """Saves pdf to buffer object
+    """
+    options = options or {}
+    # https://timvdlippe.github.io/devtools-protocol/tot/Page#method-printToPDF
+    result = send_devtools(driver, "Page.printToPDF", options)
+
+    cached_file = BytesIO()
+    cached_file.write(base64.b64decode(result["data"]))
+    cached_file.seek(0)
+    return cached_file
 
 
 def print_to_pdf(component, kwargs):
+    """Extracts content and prints pdf to buffer object.
+    """
     app = Dash(
         __name__,
         external_stylesheets=[
-        "https://www1.pennmedicine.org/styles/shared/penn-medicine-header.css",
-        BOOTSTRAP,
-    ]
+            "https://www1.pennmedicine.org/styles/shared/penn-medicine-header.css",
+            BOOTSTRAP,
+        ],
     )
 
-    layout = Div([
-        dcc.Location(id="url", refresh=False),
-        dbc.Container(
-        children=component.html,
-        fluid=True,
-        className="mt-5",
-    )])
-
-    app.layout = layout
-    app.title = 'CHIME Printer'
+    app.layout = dbc.Container(children=component.html, fluid=True)
+    app.title = "CHIME Printer"
 
     outputs = component.callback(**kwargs)
 
-    @app.callback(component.callback_outputs, [Input('url', 'pathname')])
-    def callback(*args):  # pylint: disable=W0612
+    @app.callback(component.callback_outputs, list(component.callback_inputs.values()))
+    def callback(*args):  # pylint: disable=W0612, W0613
         return outputs
 
     chrome_options = webdriver.ChromeOptions()
-    chrome_options.add_argument('--headless')
+    chrome_options.add_argument("--headless")
 
     with ThreadedRunner() as starter:
-        with DashComposite(starter, browser='Chrome', options=[chrome_options]) as dc:
+        with DashComposite(starter, browser="Chrome", options=[chrome_options]) as dc:
             dc.start_server(app, port=8051)
-            while 'Loading...' in dc.driver.page_source:
+            while "Loading..." in dc.driver.page_source:
                 sleep(1)
-            filename = f'chime-{str(uuid.uuid4())[:8]}.pdf'
-            save_as_pdf(dc.driver, f'{UPLOAD_DIRECTORY}/{filename}', {'landscape': False})
+            pdf = save_as_pdf(dc.driver, {"landscape": False})
             dc.driver.quit()
-    return f'/download/{filename}'
+
+    return pdf

src/chime_dash/app/components/sidebar.py

@@ -21,5 +21,4 @@ regional_parameters: Regional Parameters
 spread_and_contact: Spread and Contact Parameters
 severity_parameters: Severity Parameters
 display_parameters: Display Parameters
-save_as_pdf: Generate PDF
-download_report: Download Report
+download_as_pdf_link: Download Report