I'd like to discuss the short development history of this web application.
The Original Plan
The problem with My Maps is that each marker had be placed individually, and that's tedious: at least to me. What I needed was a programmatic way to feed a set of addresses, determine each address' coordinates (you know, latitude, longitude) and place markers in a custom map.
For that I wanted the Google Maps API in Javascript, and if I had to use the Javascript API for determining coordinates, I might as well use it to build the map from scratch.
The Prototype
The prototype was written in pure Javascript, using the Google Maps API. It was really basic; routes were stored in JSON (natch), and the whole app lived inside a Google Maps widget.To get started with the API I found an excellent Google Maps API Tutorial written by Mike Williams. The relevant entries were the entries on Markers and info windows, Polylines from XML and Geocoding Multiple Addresses.
In fact, I hacked a version of the geocoding example by adding all the jitney stop addresses, and from that I got the coordinates of most of the map markers. For those addresses that the API couldn't parse, I used a tedious trial and error process.
The prototype took five hours to write: one hour to parse and codify the data, one hour for figuring out how to get reasonable coordinates for each address, and three hours to get my head around Javascript. For me, writing Javascript is like this: trial, error, trial, error, google, trial, trial, error, trial, error, google, but by the end, I got a map that showed all the jitney stops and their paths.Two issues with writing the app in Javascript were my basic lack of comfort with Javascript, and also, the app didn't render on my Android phone. I dreaded debugging a web app on an Android phone.
The Rewrite
(This is a great time to point out that I think that GWT is magic, and the GWT team are a bunch of magicians.)
Thanks to GWT the app ran perfectly fine on Android. But more important, thanks to GWT I could write code in a more familiar style, and easily manipulate the DOM outside the web page's map object.
So I did.
Spit and Polish
One of the features was to replace the straight lines from stop to stop with paths along the street. The township had a map that laid out the supposed bus paths, so the trick was finding the coordinates where the paths turn. That turned out to be surprisingly easy with this small piece of Java:
map.addMapClickHandler(new MapClickHandler()
@Override
public void onClick(MapClickEvent event) {
System.out.println(event.getLatLng());
}
});
Then it was just a matter of running the web application and clicking each spot along the path, feeding the console output back to the web application as intermediate points.
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Before | After |
Besides adding features, I spent a ton of time dealing with things like positioning and formatting. I spent 30 minutes building a general purpose route building API. I spent 15 minutes on a general purpose algorithm for calculating the center of a group of points. 30 minutes went into making a widget that looks like, but isn't quite, an anchor tag. I spent endless time playing with different types of GWT panels, setting widths, heights and spans. I played with CSS. I failed at CSS, and then I played with it some more. It seems I have the same development cycle for CSS that I do with Javascript: trial, error, trial, error, google.
But also, I'd like to use Street View to show each stop. Unfortunately, while a Street View API exists in the Javascript API, there's no equivalent in the GWT API. I probably spent about two hours before I recognized that it would involve another painful, endless cycle of trial, error, trial, error, google. Too bad.
Done.
By Sunday night the app was done, and so was I. But it's still not done. Even with such a small one-off project, there so many features that could be added. For instance, while the app runs on Android (and reportedly the iPhone) it's not really built for small phones. The individual links are too small to be useful.But also, I'd like to use Street View to show each stop. Unfortunately, while a Street View API exists in the Javascript API, there's no equivalent in the GWT API. I probably spent about two hours before I recognized that it would involve another painful, endless cycle of trial, error, trial, error, google. Too bad.
Done?
Damn. While writing this post, someone provided feedback, requesting a feature that made too much sense not to implement. So instead of cleaning up this post I'm reading about geocoding again. I love writing software.
