I have a script which takes uploaded data, munges it together, turns it into a plot (using Bokeh) and then exports it to a directory as JSON.
At some point in the future, a user can hit the right URL and the appropriate plot should be displayed to the user as part of the HTML template.
I can generate the plot. I can save it as JSON. I can get the URL to retrieve it as JSON, but I cannot get the JSON plot to render within the template.
I've had a dig around the Bokeh documentation and examples, but they all seem to use a flask app to serve the pages.
I think I'm on the right track, using views.py to find and return JSON as part of a render() response, and then have Bokeh.embed.embed_items() do the work in the template to make it look right, but it's not working out - everything but the plot is displayed.
1) Create the plot and puts it in the directory for later use (app/results/1)
create plot.py
import os
import json
from django.conf import settings
from bokeh.embed import json_item
from bokeh.plotting import figure
x=[1,2,3,4,5]
y=[0,-1,-2,3,4]
p=figure(title="test_example")
p.line(x, y)
#json_export = json_item(p, "result")
json_export = json_item(p)
with open(os.path.join(settings.RESULTS_DIR,"1", "test.json"), 'w') as fp:
fp.write(json.dumps(json_export))
2) Set up the url
urls.py
urlpatterns=[
path('result/<int:pk>', views.resultdetailview, name='result-detail'),
]
3) Take the request, use the pk to find the plot json and render it all in the appropriate template.
views.py
def resultdetailview(request, pk):
results=str(pk)
with open(os.path.join(settings.RESULTS_DIR, results, "test.json"), 'r') as fp:
#data=json.load(fp)
data=json.loads(fp.read())
#context={'result':data}
#return render(request, 'app/sandbox_detail.html', context)
return render(request=request,
context={'json_object':data, 'resources':CDN.render()})
NB: If I instead use return JsonResponse(data, safe=False) then the url returns the json successfully ...
I think therefore that the issue is in the template.
4) Show the wonderous plot to the user
sandbox_detail.html
<header>
<link rel="stylesheet" href="http://cdn.bokeh.org./bokeh/release/bokeh-0.11.1.min.css" type="text/css" >
<script type="text/javascript" src="http://cdn.bokeh.org./bokeh/release/bokeh-0.11.1.min.js"> </script>
</header>
<h1> Title: Test </h1>
<div>Test</div>
<body>
<div id="result"></div>
<script>
Bokeh.embed.embed_item({{json_object}}, "result");
</script>
</body>
This template renders everything but the 'result' div.
What have I missed?
This is what I see so far:
FIRST: You are mixing 2 methods for injecting plot json data into the page.
According to documentation you can do it using either of these two methods:
1) specify the div directly:
Python: json_data = json.dumps(json_item(p, "myplot"))
JavaScript: Bokeh.embed.embed_item(item);
2) specify the div in embed_item function:
Python: json_data = json.dumps(json_item(p))
JavaScript: Bokeh.embed.embed_item(item, "myplot");
But not both of them at the same time. Could this be the problem?
SECOND: Preferably don't insert Bokeh resources by hand: rather use CDN.render() or INLINE.render() to automatically include all that your script needs:
import json
from bokeh.resources import CDN
return render(request = request,
template_name = 'app/sandbox_detail.html',
context = { json_object = json.loads(json_string),
resources = CDN.render() } )
sandbox_detail.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
{{ resources }}
</head>
<body>
<div id="result"></div>
<script>
Bokeh.embed.embed_item({{ json_object }}, "result");
</script>
</body>
</html>
THIRD: Make sure what you embed in the page is json object not a string (see variable naming above)
It helps when you debug your rendered template in your browser's debug tool.
I tried a very similar approach and found one large flaw: My browser noted that it could not find the None object. The reason here is that python stores the empty value as None, while JavaScript expects a null object.
The solution? Python already translates None to null, when you run json.dumps. To keep it that way, read the json string as a string. So instead of your data=json.loads(fp.read()) use data=fp.read().
Related
I have just installed FusionCharts Suite XT v3.13.4 to use in my (Python) Django application. I have done the Getting Started Guide (https://www.fusioncharts.com/dev/getting-started/django/your-first-chart-using-django#installation-2), but I can't seem to get it to work. I don't get an error, but my page remains completely empty. I don't know what I did wrong, I followed the tutorial exactly.
dash.html
<!-- Filename: app_name/templates/index.html -->
<!DOCTYPE html>
<html>
<head>
<title>FC-python wrapper</title>
{% load static %}
<script type="text/javascript" src="{% static "https://cdn.fusioncharts.com/fusioncharts/latest/fusioncharts.js" %}"></script>
<script type="text/javascript" src="{% static "https://cdn.fusioncharts.com/fusioncharts/latest/themes/fusioncharts.theme.fusion.js" %}"></script>
</head>
<body>
<div id="myFirstchart-container">{{ output|safe }}</div>
</body>
</html>
views.py
from django.shortcuts import render
from django.http import HttpResponse
from collections import OrderedDict
# Include the `fusioncharts.py` file that contains functions to embed the charts.
#from fusioncharts import FusionCharts
from vsdk.dashboard.fusioncharts import FusionCharts
def myFirstChart(request):
#Chart data is passed to the `dataSource` parameter, like a dictionary in the form of key-value pairs.
dataSource = OrderedDict()
# The `chartConfig` dict contains key-value pairs of data for chart attribute
chartConfig = OrderedDict()
chartConfig['caption'] = 'Countries With Most Oil Reserves [2017-18]'
chartConfig['subCaption'] = 'In MMbbl = One Million barrels'
chartConfig['xAxisName'] = 'Country'
chartConfig['yAxisName'] = 'Reserves (MMbbl)'
chartConfig['numberSuffix'] = 'K'
chartConfig['theme'] = 'fusion'
# The `chartData` dict contains key-value pairs of data
chartData = OrderedDict()
chartData['Venezuela'] = 290
chartData['Saudi'] = 260
chartData['Canada'] = 180
chartData['Iran'] = 140
chartData['Russia'] = 115
chartData['UAE'] = 100
chartData['US'] = 30
chartData['China'] = 30
dataSource['chart'] = chartConfig
dataSource['data'] = []
# Convert the data in the `chartData`array into a format that can be consumed by FusionCharts.
#The data for the chart should be in an array wherein each element of the array
#is a JSON object# having the `label` and `value` as keys.
#Iterate through the data in `chartData` and insert into the `dataSource['data']` list.
for key, value in chartData.items():
data = {}
data['label'] = key
data['value'] = value
dataSource['data'].append(data)
# Create an object for the column 2D chart using the FusionCharts class constructor
# The chart data is passed to the `dataSource` parameter.
column2D = FusionCharts("column2d", "ex1" , "600", "400", "chart-1", "json", dataSource)
return render(request, 'dash.html', {'output' : column2D.render(), 'chartTitle': 'Simple Chart Using Array'})
urls.py
from django.shortcuts import render
from django.urls import path
from vsdk.dashboard.fusioncharts import FusionCharts
from . import views
from django.conf.urls import url, include
urlpatterns = [
url(r'^$', views.myFirstChart, name = 'demo'),
]
The instructions in the "Getting Started Guide" are a bit confusion and there are some errors. Here is my working version of the Fusionchart example.
Fusionchart example
You can use FusionCharts to render charts in html. I have based the example on the Getting Started Guide and tweaked here and there to make it work. To replicate just do the following:
copy my github code, this will create an new project directory fusionchart_example.
git clone https://github.com/bvermeulen/fusionchart_example
The tree structure should look like:
go to this folder and create a virtual environment for Django, note I work with Python 3.6.8, but likely other python 3.6 or 3.7 would work ok as well.
python -m venv ./venv
activate the environment (Linux)
source ./venv/bin/activate
(or Windows)
./venv/scripts/activate
with the virtual environment enabled install Django
pip install django==2.2.3
You can now run the app
python manage.py runserver
and view the result in your browser at 127.0.0.1:8000 that should look like:
You can review the source code when you have cloned my github, especially settings.py, but I give urls.py, views.py and chart.html below as first reference.
urls.py:
from django.urls import path
from render_graph import views
urlpatterns = [
path('', views.chart, name='chart'),
]
views.py:
from django.shortcuts import render
from django.http import HttpResponse
from collections import OrderedDict
# Include the `fusioncharts.py` file that contains functions to embed the charts.
from fusioncharts import FusionCharts
from pprint import pprint
def chart(request):
#Chart data is passed to the `dataSource` parameter, like a dictionary in the form of key-value pairs.
dataSource = OrderedDict()
# The `chartConfig` dict contains key-value pairs of data for chart attribute
chartConfig = OrderedDict()
chartConfig["caption"] = "Countries With Most Oil Reserves [2017-18]"
chartConfig["subCaption"] = "In MMbbl = One Million barrels"
chartConfig["xAxisName"] = "Country"
chartConfig["yAxisName"] = "Reserves (MMbbl)"
chartConfig["numberSuffix"] = "K"
chartConfig["theme"] = "fusion"
# The `chartData` dict contains key-value pairs of data
chartData = OrderedDict()
chartData["Venezuela"] = 290
chartData["Saudi"] = 260
chartData["Canada"] = 180
chartData["Iran"] = 140
chartData["Russia"] = 115
chartData["UAE"] = 100
chartData["US"] = 30
chartData["China"] = 30
dataSource["chart"] = chartConfig
dataSource["data"] = []
# Convert the data in the `chartData`array into a format that can be consumed by FusionCharts.
#The data for the chart should be in an array wherein each element of the array
#is a JSON object# having the `label` and `value` as keys.
#Iterate through the data in `chartData` and insert into the `dataSource['data']` list.
for key, value in chartData.items():
dataSource["data"].append({'label':key, 'value': value})
# print the datasource to see what will be rendered
pprint(dataSource)
# Create an object for the column 2D chart using the FusionCharts class constructor
# The chart data is passed to the `dataSource` parameter.
column2D = FusionCharts("column2d", "Oil_Reserves", "600", "400", "Oil_Reserves-container", "json", dataSource)
context = {'output': column2D.render(), }
return render(request, 'chart.html', context)
chart.html:
<!DOCTYPE html>
<html>
<head>
<title>Oil Reserves</title>
{% load static %}
<script type="text/javascript" src="{% static 'fusioncharts/types/fusioncharts.js' %}"></script>
<script type="text/javascript" src="{% static 'fusioncharts/themes/fusioncharts.theme.fusion.js' %}"></script>
<link rel="icon" href="data:,">
</head>
<body>
<div id="Oil_Reserves-container">{{ output|safe }}</div>
</body>
</html>
Fusioncharts says this is a trial version, so better check if any costs are involved. Let me know if you need any more info. Good luck...
Bruno Vermeulen
bruno.vermeulen#hotmail.com
8 July 2019
Django newbie here: my aim is to integrate Folium to an html page. so what I have at the moment:
polls/views.py
def show_map(request):
#creation of map comes here + business logic
m = folium.Map([51.5, -0.25], zoom_start=10)
test = folium.Html('<b>Hello world</b>', script=True)
popup = folium.Popup(test, max_width=2650)
folium.RegularPolygonMarker(location=[51.5, -0.25], popup=popup).add_to(m)
context = {'my_map': m}
return render(request, 'polls/show_folium_map.html', context)
polls/urls.py
urlpatterns = [
path('show_my_map', views.show_map, name='show_map'),
]
and show_folium_map.html
<h1>map result comes here</h1>
{{ my_map }}
problem is that I get the 'to_string' value of the map (I promise you I saw that coming). So how can I integrate the map in such way that I can actually see the map and also define the size?
In order to really include folium into custom django template you have to render your figure first before adding it to context (This will recursivly load all parts of the map into the figure). Afterwards in your template, you have to access header, html and script parts of figure seperatly by calling their render function. Additionally, those parts have to marked as "safe" by django template tag in order to allow html insertion. See example below.
Example:
views.py:
import folium
from django.views.generic import TemplateView
class FoliumView(TemplateView):
template_name = "folium_app/map.html"
def get_context_data(self, **kwargs):
figure = folium.Figure()
m = folium.Map(
location=[45.372, -121.6972],
zoom_start=12,
tiles='Stamen Terrain'
)
m.add_to(figure)
folium.Marker(
location=[45.3288, -121.6625],
popup='Mt. Hood Meadows',
icon=folium.Icon(icon='cloud')
).add_to(m)
folium.Marker(
location=[45.3311, -121.7113],
popup='Timberline Lodge',
icon=folium.Icon(color='green')
).add_to(m)
folium.Marker(
location=[45.3300, -121.6823],
popup='Some Other Location',
icon=folium.Icon(color='red', icon='info-sign')
).add_to(m)
figure.render()
return {"map": figure}
templates/folium_app/map.html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
{{map.header.render|safe}}
</head>
<body>
<div><h1>Here comes my folium map:</h1></div>
{{map.html.render|safe}}
<script>
{{map.script.render|safe}}
</script>
</body>
</html>
You can try the below way. I also had faced the same issue and it worked great for me.
views.py
def show_map(request):
#creation of map comes here + business logic
m = folium.Map([51.5, -0.25], zoom_start=10)
test = folium.Html('<b>Hello world</b>', script=True)
popup = folium.Popup(test, max_width=2650)
folium.RegularPolygonMarker(location=[51.5, -0.25], popup=popup).add_to(m)
m=m._repr_html_() #updated
context = {'my_map': m}
return render(request, 'polls/show_folium_map.html', context)
show_folium_map.html
{{ my_map|safe }}
You can get the html as a string by triggering the rendering on the (internal) parent of Map:
m = folium.Map()
html: str = m.get_root().render()
Note that this returns a full html page, so you may need to put it in an iframe.
Alternatively, you can render the head, body and script parts separately. That way you can put each part on your page where it belongs and you don't need an iframe:
m = folium.Map()
html_head: str = m.get_root().header.render()
html_body: str = m.get_root().html.render()
html_script: str = m.get_root().script.render()
So I have a standard Django project with a basic view that returns a simple HTML confirmation statement. Would it be plausible for me to define all of my HTML in the view itself as a really long string and return that using HttpResponse() I know it's a bit unorthodox, but this is an example of what I'm thinking about:
from django.shortcuts import render
from django.http import HttpResponse
from django.shortcuts import render_to_response
def index(request):
html = """
<html>
<body>
This is my bare-bones html page.
</body>
</html>
"""
return HttpResponse(html)
My corresponding JS and stylesheets would be stored in the same directory as views. py in my app in this example. Just making sure: I'm not asking if this works, because I already know the answer is yes, I just want to know if there are any disadvantages/drawbacks to this method, and why don't more people do this?
You can use built-in template renderer to get works filters/templatetags/etc
Most people dont use this because it mixes Python with HTML and gets very messy and out of hand very quickly
To answer your question, this solution works alright, but it is not adopted by many programmers because it makes the whole code disorganized and not easy to understand.
Also, this system would not be good for large projects because the code would contain lots of html in the same file as the python. It is always nice and time saving to separate code into files based on performance.
A better solution
Save your html in a folder called templates in the current directory, in this case, the templates folder can contain an index.html file which would have
<html>
<body>
This is my bare-bones html page.
</body>
</html>
in the views create an index view for this template using the code below
def index(request):
return render(request, 'index.html')
if you would need to pass in some data to the html you can use context in the request as shown below:
def index(request):
context = {
"name":"some name"
}
return render(request, 'index.html', context=context)
access the data in html using the structure below:
<html>
<body>
The data passed to the page is {{name}}.
</body>
</html>
I hope this helps
I'm new to django and bokeh.
I was trying to render a simple bokeh plot supported by a few select options that essentially allow me to tweak my plot's content in a django web application.
The plots are rendered when the script and div elements obtained from the bokeh.embed.components() are passed to the template as context variables.
The same didn't work when i had a widget and a plot held in a bokeh.io.vform object.
I get the output right when i perform a bokeh.io.show(), by specifying the bokeh.plotting.output_file(), but I'm trying to get this running in my web application.
Am I missing anything? Or is there any other approach that serves my intent?
my code to just render a bokeh widget is as follows:
views.py
#django imports
from bokeh.embed import components
from bokeh.plotting import figure
from bokeh.io import vform
from bokeh.models.widgets import Select
def test(request):
s = Select(title="test", value="a", options=['a','b','c'])
script,div = components(s)
return render(request,'test.html',RequestContext(request,{'script':script,'div':div}))
test.html
<html>
<head>
<link href="http://cdn.bokeh.org/bokeh/release/bokeh-0.11.1.min.css" rel="stylesheet" type="text/css">
<script src="http://cdn.bokeh.org/bokeh/release/bokeh-0.11.1.min.js"></script>
</head>
{% load staticfiles %}
<body>
{{ div | safe }}
{{ script | safe }}
</body>
</html>
I would expect a select form element to be rendered when test.html is launched from test() in django. but doesn't happen.
BokehJS was recently split up into separate pieces to provide more flexible options for usage depending on what parts of the library are actually being used. Because loading resources is normally automatically handled in many cases, it was unintentioinally neglected to mention this split prominently in the docs. However, it is important to know about for embedding. There is an issue to update the docs, but what you need to know is that if you are using widgets, you now also need to load additional scripts from CDN:
http://cdn.bokeh.org/bokeh/release/bokeh-widgets-0.11.1.min.js
http://cdn.bokeh.org/bokeh/release/bokeh-widgets-0.11.1.min.css
I have data in csv format and I want to create a webpage with charts or tables. I'm using the Pyramid Framework, chameleon, and deform_bootstrap.
I'm new to web development and there doesn't seem to be any tutorials for this out there. Can anyone point me in the right direction?
Without knowing more details its difficult to say. However, basically you will need a route registered in your config (in the root __init__.py file), a view callable (this can be just a method) to read the file and pass the data to a renderer and a chameleon template to render the data.
First set a route in your configuration. For example, to add a route for the table and one for the chart you could do something like this in your __init__.py file.
config.add_route('show_table', '/table')
config.add_route('show_chart', '/chart')
The choice of names and paths is up to you of course.
Then, you need to implement a view callable for each route. These would read the file and return a dictionary containing the data. They also tie the data to a particular renderer, in your case a chameleon template. Something like this might be right for your case where both routes need the same data.
from pyramid.view import view_config
def read_file():
"""read the file and return the data in a suitable format"""
return [1,4,2,4,56,7,45,3]
#view_config(route_name='show_table', renderer='templates/table.pt')
def table_view(request):
data = read_file()
return {'data': data}
#view_config(route_name='show_chart', renderer='templates/chart.pt')
def chart_view(request):
data = read_file()
return {'data': data}
Finally, you will need to implement the template files. These will be different depending on what you need.
<!DOCTYPE html>
<html xmlns:tal="http://xml.zope.org/namespaces/tal">
<head>
</head>
<body>
<table>
<tr><th>Data</th></tr>
<tr tal:repeat="datum data"><td>${datum}</td></tr>
</table>
</body>
</html>
To make charts I use d3.js but this is another question I think. Here is a simple example based on the first steps in this tutorial. First your template needs to make the data available to javascript. One way is to write the data into a javascript variable. This will work but is a bit messy - see this question for alternative approaches. In a real app you might want to use ajax so you would be writing the url to access the data here.
<!DOCTYPE html>
<html xmlns:tal="http://xml.zope.org/namespaces/tal">
<head>
<script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
</head>
<body>
<div class="chart"></div>
<script type="text/javascript">
var data = ${data};
var x = d3.scale.linear()
.domain([0, d3.max(data)])
.range([0, 420]);
d3.select(".chart")
.selectAll("div").data(data)
.enter().append("div")
.style("width", function(d) { return x(d) + "px"; })
.text(function(d) { return d; });
</script>
</body>
</html>
This should work but is untested, if you have any problems let me know and I will update it when I have a moment.