3. Widgets¶
To place widgets in your dashboard you need to create a javascript file, where you call each widget that you need to place with the correct options, each widget provides an event that you can call in any javascript file to update the data.
For example if you create a number widget
var dashboard = new Dashboard();
...
dashboard.addWidget('current_valuation_widget', 'Number', {
getData: function () {
$.extend(this.scope, {
title: 'Current Valuation',
moreInfo: 'In billions',
updatedAt: 'Last updated at 14:10',
value: '$35',
detail: '64%'
});
}
});
Then you can publish at any moment the event dashboard.publish('example_widget/getData')
to get new data and update the widget.
Note that in this example the getData method will be executed each 1000 milliseconds because it is the default value of interval option in a Number widget.
3.1. Clock Widget¶
This widget can display a specific day or an hour.
3.1.1. Options¶
- row
- Number of rows occupied by the widget. (default: 1)
- col
- Number of columns occupied by the widget. (default: 1)
- scope
JSON object that represent the date and time in format
{ time: 'hh:mm:ss', date: 'Month Day DD sYYYY' }
- getData
- Function responsible to update the scope value, this function is executed each time interval specified in interval variable. You can rewrite this function to get data from an external source. (default: return the browser time in a valid JSON format)
- getWidget
- Return the DOM element that represent the widget.
- interval
- Actualization interval of widget scope on milliseconds. (default: 500)
3.2. Graph Widget¶
This widget can display a value with an associated graph as a background.
3.2.1. Options¶
- row
- Number of rows occupied by the widget. (default: 1)
- col
- Number of columns occupied by the widget. (default: 2)
- scope
JSON object in this format
{ data: [ {x: /x0/, y: /y0/}, {x: /x1/, y: /y1/} ... ], value: /string/, title: /string/, moreInfo: /string/, beforeRender: /function/, afterRender: /function/, xFormat: /function/, yFormat: /function/, properties: /object/, }
- getData
- Function responsible to update the widget scope, this function is executed each time interval specified in interval variable. You can rewrite this function to get data from an external source. (default: empty function)
- getWidget
- Return the DOM element that represents the widget.
- interval
- Actualization interval of widget scope on milliseconds. (default: 1000)
3.2.2. Graph options¶
To render the graph this widget use Rickshaw library, for now the config options are quite limited, if you need to be more specific you can overwrite the rivetsjs binder (rv-dashing-graph) or write a custom widget using this as a guide.
To configure the X and Y axis you must define custom methods xFormat and yFormat in the scope, also you can use the methods beforeRender and afterRender to execute arbitrary javascript before or after rendering, for example:
function xFormat(n) {
return '(' + n + ')';
};
Dashing.utils.get('my-registered-widget-url-name', function(scope) {
scope.xFormat = xFormat;
scope.afterRender = function() {
alert('graph shown');
};
$.extend(self.scope, scope);
});
Also, you can specify any properties that the graph constructor accepts in the scope object, for example a valid scope may be:
{
data: [
{ x: 0, y: 29 },
{ x: 1, y: 42 },
{ x: 2, y: 12 }
],
value: 12,
title: 'Yeah!',
moreInfo: 'Django Rocks',
properties: {
renderer: 'line',
padding: {
top: 0.1,
right: 0.1
}
},
}
3.2.3. Python Class¶
This class helps return valid scope to be used by the widget, you can see the definition in GitHub
Here is an example of a graph widget where value is displayed the total number of Errands and in data returns an array with the last two hour of activity
from dashing.widgets import GraphWidget
class HourlyErrandsWidget(GraphWidget):
title = 'Hourly Errands'
more_info = ''
def get_value(self):
return SearchQuerySet().filter(django_ct='errands.errand').count()
def get_data(self):
latest_hours = datetime.now() - timedelta(hours=2)
latest_errands = SearchQuerySet().filter(
django_ct='errands.errand',
created__gt=latest_hours).values('created')
intervals = []
for errand in latest_errands:
delta = datetime.now() - errand['created']
for m in range(10, 120, 10):
if delta < timedelta(minutes=m):
intervals.append(13 - m/10)
break
rlist = Counter([x for x in intervals])
return [{'x': x, 'y': y} for x, y in rlist.most_common()]
3.3. List Widget¶
This widget can display a list of elements with an associated value.
3.3.1. Options¶
- row
- Number of rows occupied by the widget. (default: 2)
- col
- Number of columns occupied by the widget. (default: 1)
- render
- Function responsible of modify the DOM elements of the widget.
- scope
JSON object in this format
{ data: [ { label: /string/, name: /string/ }, { label: /string/, name: /string/ }, ... ], title: /string/, moreInfo: /string/, updatedAt: /string/ }
- getData
- Function responsible to update the scope value, this function is executed each time interval specified in interval variable. You can rewrite this function to get data from an external source. (default: empty function)
- getWidget
- Return the DOM element that represent the widget.
- interval
- Actualization interval of widget data on milliseconds. (default: 10000)
3.3.2. Python Class¶
This class helps to return valid data to be use by the widget, you can see the definition in GitHub
Here’s an example of a graph widget where in the scope returns an array with the messengers who have more requests
from dashing.widgets import ListWidget
class ActiveMessengersWidget(ListWidget):
title = 'Active Messengers'
moreInfo = 'Those who have more requests'
def get_updated_at(self):
modified = SearchQuerySet().filter(
django_ct='errand').order_by('-modified')[0].modified
return u'Last updated {}'.format(modified)
def get_data(self):
messengers = SearchQuerySet().filter(
django_ct='messengers', active=True)
rlist = Counter([x for x in messengers])
return [{'label':x, 'value':y} for x, y in rlist.most_common(20)]
3.4. Number Widget¶
This widget can display a value with other interesting information.
3.4.1. Options¶
- row
- Number of rows occupied by the widget. (default: 1)
- col
- Number of columns occupied by the widget. (default: 1)
- scope
JSON object in this format
{ value: /string/, title: /string/, detail: /string/, moreInfo: /string/, updatedAt: /string/ }
- getData
- Function responsible to update the scope value, this function is executed each time interval specified in interval variable. You can rewrite this function to get data from an external source. (default: empty function)
- getWidget
- Return the DOM element that represent the widget.
- interval
- Actualization interval of widget scope on milliseconds. (default: 1000)
3.4.2. Python Class¶
This class helps to return valid data to be used by the widget, you can see the definition in GitHub
Here is an example of a graph widget where in value is displayed the total of payments and in the detail and moreInfo shows other information of interest
from dashing.widgets import NumberWidget
class PaymentsWidget(NumberWidget):
title = 'Payments Customers'
def get_value(self):
return Payment.objects.all().count()
def get_detail(self):
payments = Payment.objects.all()
total = len([x for x in payments if x.status == Payment.STATUS.waiting])
return '{} to approve'.format(total)
def get_more_info(self):
payments = Payment.objects.all()
total = len([x for x in payments if x.status == Payment.STATUS.rejected])
return '{} rejected'.format(total)
3.5. Knob Widget¶
This widget can display a dial with other interesting information.
3.5.1. Options¶
- row
- Number of rows occupied by the widget. (default: 1)
- col
- Number of columns occupied by the widget. (default: 1)
- scope
JSON object in this format
{ title: /string/, moreInfo: /string/, value: /number/, data: { // jquery knob options http://anthonyterrien.com/knob/ angleArc: /number/, fgColor: /string/, angleOffset: /number/, displayInput: /boolean/, displayPrevious: /boolean/, step: /number/, min: /number/, max: /number/, readOnly: /boolean/ } }
- getData
- Function responsible to update the scope value, this function is executed each time interval specified in interval variable. You can rewrite this function to get data from an external source. (default: empty function)
- getWidget
- Return the DOM element that represent the widget.
- interval
- Actualization interval of widget scope on milliseconds. (default: 10000)
3.6. Map Widget¶
This widget display a google map widget with one or more markers grouped
3.6.1. Options¶
- row
- Number of rows occupied by the widget. (default: 1)
- col
- Number of columns occupied by the widget. (default: 1)
- scope
JSON object in this format
{ theme: /black|blue|gray|green|orange|red|white|yellow/ map: { zoom: /number/, doubleClickZoom: /boolean/, defaultUI: /boolean/, center: { lat: /number/, lng: /number/ }, markers: [ { lat: /number/, lng: /number/ }, { lat: /number/, lng: /number/ } ] } }
- getData
- Function responsible to update the scope value, this function is executed each time interval specified in interval variable. You can rewrite this function to get data from an external source. (default: empty function)
- getWidget
- Return the DOM element that represent the widget.
- interval
- Actualization interval of widget scope on milliseconds. (default: 0)
4. Custom Widgets¶
To make a custom widget you must create three static files to define configuration parameters and appearance. In addition, you can create a python class to communicate with the Django project.
To name your widgets should follow a naming convention were the name must be unique and searchable through the settings.
4.1. Static Files¶
4.1.1. Template File¶
Its location should be <static_directory>/widgets/<widget_name>/<widget_name>.html
this file describes its UI in plain HTML using the Rivets.js conventions to bind data to the script file.
For example {% static %}widgets/list/list.html
looks like this:
<div>
<h1>{ scope.title }</h1>
<ul>
<li rv-each-item="data">
<span class="label">{ item.label }</span>
<span class="value">{ item.value }</span>
</li>
</ul>
<p class="more-info">{ moreInfo }</p>
<p class="updated-at">{ updatedAt }</p>
</div>
The classes are only for the stylesheet.
4.1.2. Style File¶
Your location should be <static_directory>/widgets/<widget_name>.css
in this file defines the styles of widget.
4.1.3. Script File¶
Your location should be <static_directory>/widgets/<widget_name>.js
in this file will be defined the configuration options and default values for the new widget, the idea is to create an object using the new
keyword, then we define properties and methods using this
keyword.
We must provide an __init__
method were we bind the scope with the template and add to the dashboard, this function is quite similar in all widgets, then it is provided by Dashing.utils.widgetInit
to facilitate implementation and improve the lecture of widgets, also must provide a scope
element which will be binded to the template, and a getData
function will surely be the to be overwritten to obtain relevant data as required,
For example {% static %}widgets/list/list.js
looks like this:
/* global Dashboard */
Dashing.widgets.List = function (dashboard) {
var self = this,
widget;
this.__init__ = Dashing.utils.widgetInit(dashboard, 'list');
this.row = 2;
this.col = 1;
this.scope = {};
this.getWidget = function () {
return widget;
};
this.getData = function () {};
this.interval = 10000;
};
If we want to initialize widget with the scope we can write:
...
this.col = 1;
this.socpe = {
title: 'Default Title',
moreInfo: 'No data to display'
};
this.getWidget = function () {
...
4.2. Python Class¶
Surely in many cases it may be necessary to give the option to get some Dajngo project data into the widget, for this dashing has a Widget class that can be inherited to deliver properly serialized data, subsequently serving data using the dashing router.
For example ListWidget in dashing/widgets.py
looks like this:
class ListWidget(Widget):
title = ''
more_info = ''
updated_at = ''
data = []
def get_title(self):
return self.title
def get_more_info(self):
return self.more_info
def get_updated_at(self):
return self.updated_at
def get_data(self):
return self.data
def get_context(self):
return {
'title': self.get_title(),
'moreInfo': self.get_more_info(),
'updatedAt': self.get_updated_at(),
'data': self.get_data(),
}
If you develop your widget with python classes it is necessary that you distribute it via PyPI
4.3. Distribution¶
To distribute a widget you have two options. The fastest way is through Django Dashing Channel but it is a bit limited, and through PyPI, a bit trickier to pack but you have more options when developing the widget.
4.3.1. Via Django Dashing Channel¶
Using this distribution method the users will only have to add the widget name on INSTALLED_WIDGETS
then load the dashboard, this locates the static files from a remote location (specified in the preconfigured repository), if the user creates a copy of the files on your local static directory then these will open locally.
You will have to host your files into a CDN, I recommend creating a github project and use RawGit to serve through MaxCDN, you can take dj-dashing-weather-widget project as a guide.
Finally to publish your widget in Django Dashing Channel you need to make a fork of django-dashing-channel, add your repository to repositories.json and send a pull request. In the repository root will be sought the widget static files (.js .css and .html)
You should create a README file for installation instructions.
4.3.2. PyPI Package¶
If your widget requires python code or you just want to provide an easy way to get the widget locally then a PyPI package is the way to go.
As a requirement it is necessary follow the widgets naming convention (see static files). To create a PyPI package see the documentation, and should create a README file for installations instructions.
This is not excluding the previous way, you could create a minimalist version of your widget and upload it to django-dashing-channel and in the project instructions show how to install the PyPI version