If you're interested in contributing to this program, here are some
guidelines. Mail patches to gpsbabel-code@lists.sourceforge.net for
consideration and integration.
Rules to Live By
----------------
Standards are good. ISO C and POSIX are greatly preferred.
Reuse is good, if doing so is not onerous. For example, using the expat
libraries vastly simplifies the XML parsers while increasing their
robustness plus those libraries are ubiquitous. So I consider it OK to
require expat.
You may find format_skeleton.c and filter_skeleton.c in the source tree
to be helpful examples. Just add meat!
Compilers complain for a reason. Code shouldn't emit warnings.
The entire world doesn't run <your OS here>. I've tested this code on
at least five different OSes. If you find yourself wanting to insert
compiler or OS specific magic, please resist.
Coding consistency is encouraged. The reality is we have a lot of code
that was written by different authors. Some code from other projects is
included. We don't have immutable rules about code style (indention,
curly location, whitespace rules, etc.) but we do ask that you try to
match what is around any code you modify. "When in Rome..."
If writing new code, we'd prefer a style like:
int
mumble(int whatever)
{
<tab>if (whatevever) {
<tab><tab>return blah;
<tab>}
}
...but if you're submitting a new source file that you intend to
maintain and are convinced that two space indents will make the world a
better place, knock yourself out. But if you need to add a line of code
to the above before "return blah" and do it with spaces instead of hard
tabs, that would be bad.
Submitting Patches
------------------
If you are creating a new target you should submit patches (use
"cvs diff -uN" to create patches) to the following files:
* Yourcode.c and/or Yourcode.h - this is the code required to do your
conversions and any support files that your code requires.
* vecs.c - an updated vecs.c file implementing your conversion code into
GPSBabel.
* Makefile - an updated Makefile telling the compiler how to build and link
your conversion into GPSBabel
* testo - an updated script that tests your conversion (this should produce
no output if all is good, see the current testo script for examples)
* YourOutput - a sample file of code produced by your function (used in testo
and lives in a directory called "reference").
* Documentation - see below.
Please ensure that you are building and testing against the latest code
from the top of the CVS tree and that any code you modify is the latest
version from the CVS - Note: code changes sometimes occur frequently!
Documentation
-------------
HTML and text documentation are generated automatically from DocBook
source located in the "xmldoc" directory. That directory contains
two subdirectories of interest: "formats" and "filters". If your
contribution adds or affects a format, you'll want to be in the "formats"
directory. Otherwise, you'll want to be in the "filters" directory.
You should contribute a file called "yourname.xml", where "yourname" is the
name you would give on the command-line to invoke your new format or filter.
For example, the arc filter is documented in "filters/arc.xml".
This file contains a general description of your format or filter, any
limitations in your support for it, and anything else the end user should
know. For file formats, links to manufacturers' websites are encouraged.
The contents of this file are not valid or even well-formed XML on their own;
they are included into a larger framework. If you know DocBook, you should
ensure that the contents of this file will validate if included in a <section>.
If you do not know DocBook, see the other files in this directory for examples
or see http://docbook.org/tdg/en/html/docbook.html for the gory details. Tags
of interest will almost certainly include <para> for paragraphs,
<ulink url="..."> for web links, and <screen format="linespecific"> for
example command lines.
For each option supported by your format or filter, you should also contribute
a file in the "options" subdirectory called "yourname-youroption.xml", again
using the names you would use on the command line to invoke your format or
filter with that particular option. For example, the "distance" option to the
"arc" filter is documented in "filters/options/arc-distance.xml". These
files are similar to the general description above, and should meet the same
validation requirements.
As of this writing, there are two formats that violate this rule: Magellan
serial and Microsoft Streets & Trips. Because those formats have the same
names as other formats, their descriptions are located in "magellan1.xml" and
"msroute1.xml" respectively. These are special cases, and you should do your
best to ensure that they remain the only special cases.
Note that the automated framework already includes the name and description of
your format and its options as described in vecs.c and yourcode.c, so there is
no need to repeat that information in your documentation.
Enjoy!
Robert Lipe,
robertlipe@usa.net