It is not
easy to find a GIS web app builder that takes you all the way from the basic
initial steps of familiarizing yourself with HMTL, CSS, and JavaScript to
fairly complicated web applications.
Building Web and Mobile ArcGIS Server Applications with JavaScript, by Eric Pimpler and published by Packt Publishing has
two main advantages: first, you can use high-quality GIS data (or at least data
that is specific to your needs), and second, you can create light apps that
work quickly over a number of different devices. You’re not likely to have
obsolete apps using HTML 5 and JavaScript, which is what is featured here.
The book is
very logically organized: you start by creating a base map, and then add layers
of data to the map, and then have it all display as a web page. You’re able to
add different types of data layers, which include tiled, dynamic, and feature.
The section on adding data layers is very robust (as it should be), and it’s
followed by adding Graphics to the Map. It’s important to keep in mind that the
graphics layer sits on top of the other layers – so, some data management /
housekeeping / filing protocols and customs are very helpful here. In this
book, the basemaps are provided by ArcGIS Online.
For a person
who does not work with GIS data or ArcGIS every day, it’s probably best to work
through the examples and see how they’re being developed. In that case, I’d look at chapter 8, “Turning
Addresses into Points and Points into Addresses,” and then work through the
example a couple of times. The chapter covers geocoding, which is at the heart
of web mapping applications. It’s the way you turn physical addresses into
latitude and longitude coordinates.
The book
clearly demonstrates how to write and test the JavaScript code in the
JavaScript Sandbox, and then it gives you a chance to practice. I also like the
little tips and tricks – example, use Notepad++ instead of Notepad for coding
(to avoid the extraneous code problems of Word, etc.).
In addition
to Geocoding, there is a very clear and easy-to-follow chapter on using
Geoprocessor, which is very good for developing models.
The appendix
gives an example of using ArcGIS templates and also Dojo in order to develop
user interfaces. This section alone is worth the price of the book. The
instructions are very clear and the screenshots appropriate and easy to follow.
Some of the
chapters contain a great deal of code and not perhaps as much detailed
explanation as might be useful for people who are fairly new. It would not be a
bad idea to have more callouts in the code to point to what exactly is
happening.
Overall,
this is a great manual – very practical and extremely timely.
Just a last
thought -- when you first read the title of the book, Building Web and Mobile ArcGIS Server Applications with JavaScript,
you may immediately ask yourself two questions:
first, why ArcGIS and why not Google Earth or Google Maps integrated
apps?; and second, why JavaScript?
First,
ArcGIS Server is the most popular and widely-used platform for developing GIS
applications for the web. It uses many different dynamic map sources, and is
not tied to just one (such as Google Earth). So, if you use ArcGIS Server, you
can incorporate the best possible map sources / GIS information.
Second,
JavaScript works really well with modern web browsers (Internet Explorer, Firefox,
Chrome, and Safari), and it works well with HTML 5. This allows maximum flexibility
with mobile applications. Using JavaScript in web applications will optimize
performance because the applications are dynamic and do not have to return to
the server for data. As a result, they are very responsive and use-friendly,
not to mention that they are also faster.
