[LRUG] review (google maps apps)

[graham]

Hi,

Not sure where reviews of the books handed out at the last meeting are 
supposed to go, so thought I'd post mine here. Maybe someone with Rails 
experience could say more than I could about the Rails side of the book 
in their review?

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Beginning Google Maps Applications with Rails and Ajax - from novice to 
professional

As it says on the tin, this book covers Google maps applications, that 
is, the Google API, rather than generic mapping principles. There is one 
very short chapter on projections of the surface of a sphere onto two 
dimensions, but that is it - this is not a GIS textbook. It is slightly 
unclear what level it is aimed at; as hinted by the title, it is either 
'beginning' Google map applications, or 'from novice to professional'. 
My guess would be that the 'beginning' version was the authors' choice 
and 'from novice to professional' added by the marketing department. The 
book does start with extremely simple examples (pretty much identical to 
what you get from Google's own site) and work towards gradually more 
complex applications, but from my personal experience of implementing 
just one Google map application the level of complexity of the final 
parts of the book is one you are likely to hit not long after starting 
to use the API, and not really one you could call 'professional'.

In introducing the Google API the book inevitably talks about Javascript 
much more than Rails. In part this is because the book is a rewrite of 
an earlier PHP version, in part because where the Ruby part of Rails is 
needed everything 'just works', so that the amount of Rails code needed 
is minimal (on the other hand the authors do spend a fair amount of time 
warning about potential pitfalls with Prototype, the Ajax library in 
Rails and ways round them). The meat of the book is therefore in the
javascript applications presented, which are both clear and generally 
useful (though not always complete - the full code is available from the 
book's website).

The biggest downside of the book for me was not the fault of the 
authors, but of the British government. The book is oriented to the US 
in particular, and in general to countries which make their geographical 
data freely available to their populations. Some chapters are based on 
the assumption that you can do direct lookups of latitude and longitude 
from postcodes, or that large geographical datasets with all kinds of 
interesting information are freely available for experimentation. This 
makes the longer practical applications simply irrelevant to anyone 
British who wishes to produce real applications without large amounts of 
investment. The one example of UK-specific mapping given uses a file of 
2,800 postcodes they found 'floating round the internet'. British users 
could do with a book which discusses such topics as organised and 
reliable attempts to bypass government-created restrictions on 
geocoding, how to convert UK Northing/Easting data to Google's latitude 
and longitude, how to make use of OpenStreetMap data, etc. This isn't 
that book, and doesn't claim to be.

Conclusion: this is a reasonable introduction to the Google map API from 
the US point of view. For a British user it does not give you much 
beyond what is available from Google itself, apart from the convenience 
of having all the information in one place wrapped around with a 
readable presentation.