In this week’s Tech Tuesday tip,we’ll give you a clue on how to use technology to help you geocache.
If you’re a premium member of Geocaching.com,you’re no doubt familiar with GPX files,which are the files you can download from the site and use in many GPS receivers and PC programs. But have you ever wondered what’s actually in a GPX file?
If you want to see,try opening a GPX document in a text editor like Windows Notepad. You’ll see that the information inside is quite readable,but everything is surrounded by signs like <,>and / like the sample below. What’s with all that?
<groundspeak:short_description html=”True”>The site where you’ll find the Angelfield virtual cache can be accessed by paved roads or you can park at the entrance and enjoy a spectacular walk of about .75 miles.</groundspeak:short_description>
If you’re familiar with the HTML syntax that’s used to create web pages,you already have an idea. GPX format uses a data description language called XML that’s very popular on the Web. XML is similar to HTML. It can be used to “tag” information for reading by other programs. Tags are simply standard strings of text that programs know how to understand. For example,if we were to describe our home town as <city>Boston</city>in an XML document,any program that reads XML would understand that Boston is a city.
A GPX file is basically a database. All of the information in the document,such as location coordinates,name,description,difficulty,size and the like,is stored and tagged separately,which means that data can be mixed and matched however you like. That’s why databases are cool. Once you break information down into its component parts,you can mix it up again in interesting ways.
What’s makes XML so powerful is that you can use it to describe anything. You can make up your own tags and use them to sort and extract information that’s important to you. For example,if you wanted to say what phase the moon was in when you logged a find,you could do that with an XML tag like <moonphase>. Or you could add the names of other cachers who were with you at the time. Third-party software programs like Geocaching Swiss Army Knife make it possible for your to modify GPX files for your own use.
Now aren’t you sorry you asked?
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