Dashboards are to enterprise GIS what the lance is to Jousting. When mounted the knight’s joust becomes the driving tip of all the energy generated from the horse and the knight. Successful dashboard has the same power, they become the driving tip of all the data generated behind them unleashing the power of the entire system at once.
This power at the tip of the dashboard can also be described as the power that empowers our GIS to be a system of engagement building on its quality of a system of record.
Today, I want to help you understand how Operations Dashboard widget development works. In this post I am going to discuss some key topics that will help you walk through the wonderful widget tutorial provided by Esri. In part two we will build on these concepts and discuss performance and tuning.
Do you want files with that?
Custom widgets are made up of several files all with a unique purpose. If you’re like me and like to think in pictures you can think of the .json as the one file that rules them all.
By ruling them all I mean to say that the files used in your UI, widget logic, UI style and thumbnail image are all defined in the .json.
This is why we call this file the manifest. Creating custom widgets requires four file types. The widget UI is defined by the HTML file and the style of the UI is defined buy the .css.
Widget business logic is stored in the .js. and finally the thumbnail that helps identify your widget.
Man I Fest you a question?
So that’s all the manifest file does is tell you where a few files are? No it does a few more things you should know about. It’s used to identify if we are building a widget, map tool or a feature action so after you figure out what your building, your next stop is the manifest file.
We also set our widget’s title, description, credits and where our widget will be getting its data from. We can configure our widget to use data from the Dashboard view, Portal Services and external AGS Services (this prompts the user for credentials).
Do I know about the Dojo? I didn’t earn this yellow belt online.
If you have been spending most of you time doing non web development you may not be familiar with the Dojo toolkit. Dojo toolkit is an open source JavaScript framework like Angular, jQuery or Ember but Dojo is built and maintained for enterprise apps generally maintained behind an organizations firewall.
One of the many advantages to this is that the Dojo toolkit can be thought of as the Swiss army knife of the JavaScript frameworks. By staying true to this design methodology the Dojo tool kit has earned a place in the enterprise development market and is supported by some BIG names.
When compared to other JavaScript frameworks one of the ways that Dojo stands out is by the tutorials to help developers get started. Leadership in the Dojo toolkit project made high quality tutorials a priority and now you get to take advantage of that. If your new to Dojo I recommend that you spend some time learning the framework.
Time spent up front with Dojo and the ArcGIS JavaScript API for that matter will pay off big time later. The time you spend getting acquainted with Dojo and the ArcGIS JavaScript API will also apply to GIS development in general. You got that right folks Dashboard development is a great place to earn your wings for GIS web development.
May the Data Source be with you
The final topic I want to cover is the concept of a data source and how we can apply only a sub set of the data source to a widget, in dashboard speak this is called making it selectable. Any layer in your map can be a data source for a widget but only layers that are exposed as feature services can be selectable.
The decision to make something selectable can be answered by asking yourself do I want my widget to highlight my entire feature class or a condition of the feature class. More will come on this in part two as we look into performace and tuning.
Conclusion
Today we discussed some of the key points that will help you get started with dashboard development like what files you need and how they are organized. We discussed the tools used to build dashboard widgets and how we plug data into our widget and control the flow of the data. Stay Tuned for part 2 where tuning and performance of your dashboard will be discused!
What do you think?