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:

myDashboard.addWidget('AvailabilityAverageWidget', 'Graph', {
    color: 'steelblue',
    scope: {
        xFormat(n) {
            return '(' + n + ')';
        },
        afterRender: function() {
            alert('graph shown');
        }
    },
    getData: function () {
        var self = this;
        Dashing.utils.get('availability', function(data) {
            $.extend(self.data, data);
        });
    },
    interval: 60000
});

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)

3.5.2. Python Class

This class helps return valid scope to be used by the widget, you can see the definition in GitHub

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)

3.6.2. Python Class

This class helps return valid scope to be used by the widget, you can see the definition in GitHub

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>/<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>/<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