== Halcyon and Potlatch 2.0 - ActionScript 3 renderer and editor ==

Potlatch 2.0 is the new version of the OpenStreetMap online editor.

Halcyon is its rendering engine. It's rules-based (like, say, Mapnik) and does dotted lines, text on a path, casing, icons for POIs, all of that.

Both are written in ActionScript 3. Potlatch 2.0 additionally uses the Flex framework.

=== What you'll need ===

* Flex SDK 3.4 or 3.5 - http://www.adobe.com/products/flex/ (free, OS X/Windows/Linux)
* AS3 docs - http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/
* Flash debug player - http://www.adobe.com/support/flashplayer/downloads.html
* Basically you might as well just sell your soul to Adobe

***Do not use FlexSDK <= 3.3 or > 4***. There are compatibility errors with version 4, and 3.3
and earlier have this bug: http://bugs.adobe.com/jira/browse/SDK-16705 which is a major issue for the
tag editors.

You'll only need OSM Rails port installed on your local machine if you are doing hard-core 
server-communication coding, but if generally you can use the dev server at api06.dev.openstreetmap.org
for development and testing.


=== How to compile and run ===

Compiling Potlatch 2:

The following command will compile potlatch2 in optimized configuration
The result is put at resources/potlatch2.swf

* mxmlc potlatch2.mxml


Compiling Halcyon as standalone viewer:

* mxmlc halcyon_viewer.as


Compiling during development:

Compiling optimized versions from scratch takes a _long_ time. There are
several ways to make it faster during development and also add useful
debug stack traces and enable the commandline debugger (at the expense
of a much larger swf file.. but we're developing so that doesn't matter!).

* fcsh
  - launches the Flex Compiler SHell -- stops the compiler having to
    bootstrap itself each time you invoke it. You don't /need/ this, but it
    does make things slightly faster (about a second a shot for me)

* mxmlc -load-config+=debug-config.xml potlatch2.mxml
  - compile potlatch2 in debug configuration -- build is incremental so you
    can run it again and mxmlc will only compile changes. Output has debug
    enabled along with decent stack traces.
    (you can substitute halcyon_viewer.as in the above to compile that)

* compile 1 
  - when using fcsh recompile the first command

* compile 1
  - type it again to compile again. You'll really wish that up-arrow,enter 
    worked, but Adobe is going laughing at you RIGHT NOW.

Running:

* Flash security model sucks. If you want to use internet resource (e.g. map calls to the dev
  server) the binary must have been served from "teh internets". Run resources/server.rb to launch a local 
  server, then go to http://localhost:3333/potlatch2.html to get started (or if you're already running e.g. 
  Apache locally, feel free to use that instead.
  
* If you are doing offline development, you will need a rails_port install. You 
  will need to add an OAuth application by going to 
  http://rails-port.local/user/<username>/oauth_clients/new
  Enter the following details (assuming the above point):
  * Name (Required): Potlatch2 (local)
  * Main Application URL (Required): http://localhost:3333/resources/potlatch2.html
  And then update resources/potlatch2.html replacing the domains.

=== Some other stuff you might need to know ===

* Flex compiler runs at about the speed of a tortoise soaked in molasses which happens also to be dead.
* Running the debug player helps when coding, since it'll pop up the runtime errors. You don't see them
  with the normal player.

Richard Fairhurst
richard@systemeD.net

Dave Stubbs
osm@randomjunk.co.uk