]> git.openstreetmap.org Git - rails.git/commitdiff
Lots of documentation updates, plus split out potlatch libraries in to lib
authorSteve Coast <steve@asklater.com>
Thu, 24 Jan 2008 16:03:56 +0000 (16:03 +0000)
committerSteve Coast <steve@asklater.com>
Thu, 24 Jan 2008 16:03:56 +0000 (16:03 +0000)
README
app/controllers/amf_controller.rb
config/environment.rb
doc/README_FOR_APP
lib/osm.rb
lib/potlatch.rb [new file with mode: 0644]

diff --git a/README b/README
index 7d3fb4c5dfb58baeddbd8aff7881650e3a3bf5b0..70a915804a4ff3f00d935f3f9762e6b432d2e8a9 100644 (file)
--- a/README
+++ b/README
@@ -1,43 +1,5 @@
-INSTALL
-=======
+Documentation
+=============
 
-* get rails working (http://www.rubyonrails.org/)
+Try `rake doc:app` and see /doc/
 
-* make your db (see db/README)
-
-* install ruby libxml bindings:
-
-   # sudo aptitude install libxml-ruby1.8 libxml-parser-ruby1.8
-
-* install primary keys plugin for active record (minimum version 0.9.1)
-  
-  # sudo gem install composite_primary_keys
-
-* make sure you have a MTA listening on localhost:25 if you want mail
-
-* script/server
-
-* thats it
-
-API CHANGES FOR EDITOR AUTHORS
-==============================
-
-See
-
-http://wiki.openstreetmap.org/index.php/REST#Changes_in_the_upcoming_0.4_API
-
-HACKING
-=======
-
-log in to your site (proably localhost:3000)
-
-create a user and confirm it
-
-you want to play with the API (probably at localhost:3000/api/0.4/node/create etc)
-
-Lots of tests are needed to test the API.
-
-Lots of little things to make the site work like the old one.
-
-Also see the 'rails_port' component for bugs:
-http://trac.openstreetmap.org/query?status=new&status=assigned&status=reopened&component=rails_port&order=priority
index 9def5104e61877efeaddf473124f7007f75411d9..876dbd10e04a4cf15dc243b382b3e21f710de0b1 100644 (file)
@@ -1,8 +1,10 @@
-# AMF Controller is a semi-standalone API for Flash clients, particularly Potlatch
+# AMF Controller is a semi-standalone API for Flash clients, particularly Potlatch.
 # All interaction between Potlatch (as a .SWF application) and the 
 # OSM database takes place using this controller. Messages are 
 # encoded in the Actionscript Message Format (AMF).
 #
+# See Also Potlatch::Potlatch and Potlatch::AMF
+#
 # Public domain.
 # editions Systeme D / Richard Fairhurst 2004-2008
 #
 #   return(-2,"message")               <-- also asks the user to e-mail me
 # to log:
 #   RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
-
 class AmfController < ApplicationController
   require 'stringio'
 
+  include Potlatch
+
   session :off
   before_filter :check_write_availability
 
@@ -31,35 +34,35 @@ class AmfController < ApplicationController
     # -------------
     # Parse request
 
-    headers=getint(req)                                        # Read number of headers
+    headers=AMF.getint(req)                                    # Read number of headers
 
     headers.times do                               # Read each header
-      name=getstring(req)                              #  |
+      name=AMF.getstring(req)                          #  |
       req.getc                                         #  | skip boolean
-      value=getvalue(req)                              #  |
+      value=AMF.getvalue(req)                          #  |
       header["name"]=value                             #  |
     end
 
-    bodies=getint(req)                                 # Read number of bodies
+    bodies=AMF.getint(req)                                     # Read number of bodies
     bodies.times do                                    # Read each body
-      message=getstring(req)                   #  | get message name
-      index=getstring(req)                             #  | get index in response sequence
-      bytes=getlong(req)                               #  | get total size in bytes
-      args=getvalue(req)                               #  | get response (probably an array)
+      message=AMF.getstring(req)                       #  | get message name
+      index=AMF.getstring(req)                         #  | get index in response sequence
+      bytes=AMF.getlong(req)                           #  | get total size in bytes
+      args=AMF.getvalue(req)                           #  | get response (probably an array)
 
       case message
-      when 'getpresets';               results[index]=putdata(index,getpresets)
-      when 'whichways';                        results[index]=putdata(index,whichways(args))
-      when 'whichways_deleted';        results[index]=putdata(index,whichways_deleted(args))
-      when 'getway';                   results[index]=putdata(index,getway(args))
-      when 'getway_old';               results[index]=putdata(index,getway_old(args))
-      when 'getway_history';   results[index]=putdata(index,getway_history(args))
+      when 'getpresets';               results[index]=AMF.putdata(index,getpresets)
+      when 'whichways';                        results[index]=AMF.putdata(index,whichways(args))
+      when 'whichways_deleted';        results[index]=AMF.putdata(index,whichways_deleted(args))
+      when 'getway';                   results[index]=AMF.putdata(index,getway(args))
+      when 'getway_old';               results[index]=AMF.putdata(index,getway_old(args))
+      when 'getway_history';   results[index]=AMF.putdata(index,getway_history(args))
       when 'putway';                   r=putway(args,renumberednodes)
         renumberednodes=r[3]
-        results[index]=putdata(index,r)
-      when 'deleteway';                        results[index]=putdata(index,deleteway(args))
-      when 'putpoi';                   results[index]=putdata(index,putpoi(args))
-      when 'getpoi';                   results[index]=putdata(index,getpoi(args))
+        results[index]=AMF.putdata(index,r)
+      when 'deleteway';                        results[index]=AMF.putdata(index,deleteway(args))
+      when 'putpoi';                   results[index]=AMF.putdata(index,putpoi(args))
+      when 'getpoi';                   results[index]=AMF.putdata(index,getpoi(args))
       end
     end
 
@@ -75,20 +78,16 @@ class AmfController < ApplicationController
       end
     }
     RAILS_DEFAULT_LOGGER.info("  Response: end")
-
   end
 
   private
 
-  # Return presets (default tags and crap) to potlatch
-  # Global is set up in config/environment.rb on startup, code is in lib/osm.rb
-  def getpresets
+  # Return presets (default tags and crap) to potlatch.
+  # Uses POTLATCH_PRESETS global, set up in OSM::Potlatch
+  def getpresets #:doc:
     return POTLATCH_PRESETS
   end
 
-  # ====================================================================
-  # Remote calls
-
   # ----- whichways
   # Find all the way ids and nodes (including tags and projected lat/lng) which aren't part of those ways in an are
   # 
@@ -98,7 +97,7 @@ class AmfController < ApplicationController
   # 2. maximum longitude
   # 3. maximum latitude
   # 4. baselong, 5. basey, 6. masterscale as above
-  def whichways(args)
+  def whichways(args) #:doc:
     xmin = args[0].to_f-0.01
     ymin = args[1].to_f-0.01
     xmax = args[2].to_f+0.01
@@ -129,7 +128,7 @@ class AmfController < ApplicationController
   #              in:   as whichways
   #              does: finds all deleted ways with a deleted node in bounding box
   #              out:  [0] array of way ids
-  def whichways_deleted(args)
+  def whichways_deleted(args) #:doc:
     xmin = args[0].to_f-0.01
     ymin = args[1].to_f-0.01
     xmax = args[2].to_f+0.01
@@ -166,8 +165,7 @@ class AmfController < ApplicationController
   #
   # FIXME: The server really shouldn't be figuring out a ways bounding box and doing projection for potlatch
   # FIXME: the argument splitting should be done in the 'talk' method, not here
-
-  def getway(args)
+  def getway(args) #:doc:
     wayid,baselong,basey,masterscale = args
     wayid = wayid.to_i
 
@@ -207,7 +205,7 @@ class AmfController < ApplicationController
   #                            [2] array of points (as getway _except_ [3] is node.visible?, 0 or 1),
   #                            [4] xmin, [5] xmax, [6] ymin, [7] ymax (unprojected bbox),
   #                            [8] way version
-  def getway_old(args)
+  def getway_old(args) #:doc:
     RAILS_DEFAULT_LOGGER.info("  Message: getway_old (server is #{SERVER_URL})")
     #  if SERVER_URL=="www.openstreetmap.org" then return -1,"Revert is not currently enabled on the OpenStreetMap server." end
 
@@ -248,7 +246,7 @@ class AmfController < ApplicationController
   #                                    [0] version, [1] db timestamp (string),
   #                                    [2] visible 0 or 1,
   #                                    [3] username or 'anonymous' (string))
-  def getway_history(args)
+  def getway_history(args) #:doc:
     wayid=args[0]
     history=[]
     sql=<<-EOF
@@ -281,7 +279,7 @@ class AmfController < ApplicationController
   #              out:  [0] 0 (code for success), [1] original way id (unchanged),
   #                            [2] new way id, [3] hash of renumbered nodes (old id=>new id),
   #                            [4] xmin, [5] xmax, [6] ymin, [7] ymax (unprojected bbox)
-  def putway(args,renumberednodes)
+  def putway(args,renumberednodes) #:doc:
     RAILS_DEFAULT_LOGGER.info("  putway started")
     usertoken,originalway,points,attributes,oldversion,baselong,basey,masterscale=args
     uid=getuserid(usertoken)
@@ -441,7 +439,7 @@ class AmfController < ApplicationController
   #                            refuses save if the node has since become part of a way
   #              out:  [0] 0 (success), [1] original node id (unchanged),
   #                            [2] new node id
-  def putpoi(args)
+  def putpoi(args) #:doc:
     usertoken,id,x,y,tags,visible,baselong,basey,masterscale=args
     uid=getuserid(usertoken)
     if !uid then return -1,"You are not logged in, so the point could not be saved." end
@@ -479,13 +477,11 @@ class AmfController < ApplicationController
   # ----- getpoi
   #              read POI from database
   #              (only called on revert: POIs are usually read by whichways)
-
   #              in:   [0] node id, [1] baselong, [2] basey, [3] masterscale
   #              does: reads POI
   #              out:  [0] id (unchanged), [1] projected long, [2] projected lat,
   #                            [3] hash of tags
-
-  def getpoi(args)
+  def getpoi(args) #:doc:
     id,baselong,basey,masterscale=args; id=id.to_i
     poi=ActiveRecord::Base.connection.select_one("SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lng,tags "+
     "FROM current_nodes WHERE visible=1 AND id=#{id}")
@@ -498,13 +494,12 @@ class AmfController < ApplicationController
 
   # ----- deleteway
   #              delete way and constituent nodes from database
-
   #              in:   [0] user token (string), [1] way id
   #              does: deletes way from db and any constituent nodes not used elsewhere
   #                            also removes ways/nodes from any relations they're in
   #              out:  [0] 0 (success), [1] way id (unchanged)
+  def deleteway(args) #:doc:
 
-  def deleteway(args)
     usertoken,way=args
 
     RAILS_DEFAULT_LOGGER.info("  Message: deleteway, id=#{way}")
@@ -552,12 +547,7 @@ class AmfController < ApplicationController
     [0,way]
   end
 
-
-
-  # ====================================================================
-  # Support functions for remote calls
-
-  def readwayquery(id,insistonvisible)
+  def readwayquery(id,insistonvisible) #:doc:
     sql=<<-EOF
     SELECT latitude*0.0000001 AS latitude,longitude*0.0000001 AS longitude,current_nodes.id,tags,visible 
       FROM current_way_nodes,current_nodes 
@@ -569,12 +559,12 @@ class AmfController < ApplicationController
     ActiveRecord::Base.connection.select_all(sql)
   end
 
-  def getlastversion(id,version)
+  def getlastversion(id,version) #:doc:
     row=ActiveRecord::Base.connection.select_one("SELECT version FROM ways WHERE id=#{id} AND visible=1 ORDER BY version DESC LIMIT 1")
     row['version']
   end
 
-  def readwayquery_old(id,version,historic)
+  def readwayquery_old(id,version,historic) #:doc:
     # Node handling on undelete (historic=false):
     # - always use the node specified, even if it's moved
 
@@ -629,7 +619,7 @@ class AmfController < ApplicationController
     rows
   end
 
-  def createuniquenodes(way,uqn_name,nodelist)
+  def createuniquenodes(way,uqn_name,nodelist) #:doc:
     # Find nodes which appear in this way but no others
     sql=<<-EOF
   CREATE TEMPORARY TABLE #{uqn_name}
@@ -654,7 +644,7 @@ class AmfController < ApplicationController
   # deleteuniquenoderelations(uqn_name,uid,db_now)
   # deleteitemrelations(way|node,'way'|'node',uid,db_now)
 
-  def deleteuniquenoderelations(uqn_name,uid,db_now)
+  def deleteuniquenoderelations(uqn_name,uid,db_now) #:doc:
     sql=<<-EOF
   SELECT node_id,cr.id FROM #{uqn_name},current_relation_members crm,current_relations cr 
    WHERE crm.member_id=node_id 
@@ -669,7 +659,7 @@ class AmfController < ApplicationController
     end
   end
 
-  def deleteitemrelations(objid,type,uid,db_now)
+  def deleteitemrelations(objid,type,uid,db_now) #:doc:
     sql=<<-EOF
   SELECT cr.id FROM current_relation_members crm,current_relations cr 
    WHERE crm.member_id=#{objid} 
@@ -684,7 +674,7 @@ class AmfController < ApplicationController
     end
   end
 
-  def removefromrelation(objid,type,relation,uid,db_now)
+  def removefromrelation(objid,type,relation,uid,db_now) #:doc:
     rver=ActiveRecord::Base.connection.insert("INSERT INTO relations (id,user_id,timestamp,visible) VALUES (#{relation},#{uid},#{db_now},1)")
 
     tagsql=<<-EOF
@@ -706,11 +696,11 @@ class AmfController < ApplicationController
     ActiveRecord::Base.connection.execute("DELETE FROM current_relation_members WHERE id=#{relation} AND member_type='#{type}' AND member_id=#{objid}")
   end
 
-  def sqlescape(a)
+  def sqlescape(a) #:doc:
     a.gsub(/[\000-\037]/,"").gsub("'","''").gsub(92.chr) {92.chr+92.chr}
   end
 
-  def tag2array(a)
+  def tag2array(a) #:doc:
     tags={}
     Tags.split(a) do |k, v|
       tags[k.gsub(':','|')]=v
@@ -718,7 +708,7 @@ class AmfController < ApplicationController
     tags
   end
 
-  def array2tag(a)
+  def array2tag(a) #:doc:
     tags = []
     a.each do |k,v|
       if v=='' then next end
@@ -728,7 +718,7 @@ class AmfController < ApplicationController
     return Tags.join(tags)
   end
 
-  def getuserid(token)
+  def getuserid(token) #:doc:
     if (token =~ /^(.+)\+(.+)$/) then
       user = User.authenticate(:username => $1, :password => $2)
     else
@@ -738,147 +728,26 @@ class AmfController < ApplicationController
     return user ? user.id : nil;
   end
 
-
-
-  # ====================================================================
-  # AMF read subroutines
-
-  # -----      getint          return two-byte integer
-  # -----      getlong         return four-byte long
-  # -----      getstring       return string with two-byte length
-  # ----- getdouble    return eight-byte double-precision float
-  # ----- getobject    return object/hash
-  # ----- getarray     return numeric array
-
-  def getint(s)
-    s.getc*256+s.getc
-  end
-
-  def getlong(s)
-    ((s.getc*256+s.getc)*256+s.getc)*256+s.getc
-  end
-
-  def getstring(s)
-    len=s.getc*256+s.getc
-    s.read(len)
-  end
-
-  def getdouble(s)
-    a=s.read(8).unpack('G')                    # G big-endian, E little-endian
-    a[0]
-  end
-
-  def getarray(s)
-    len=getlong(s)
-    arr=[]
-    for i in (0..len-1)
-      arr[i]=getvalue(s)
-    end
-    arr
-  end
-
-  def getobject(s)
-    arr={}
-    while (key=getstring(s))
-      if (key=='') then break end
-      arr[key]=getvalue(s)
-    end
-    s.getc             # skip the 9 'end of object' value
-    arr
-  end
-
-  # -----      getvalue        parse and get value
-
-  def getvalue(s)
-    case s.getc
-    when 0;    return getdouble(s)                     # number
-    when 1;    return s.getc                           # boolean
-    when 2;    return getstring(s)                     # string
-    when 3;    return getobject(s)                     # object/hash
-    when 5;    return nil                                      # null
-    when 6;    return nil                                      # undefined
-    when 8;    s.read(4)                                       # mixedArray
-      return getobject(s)                      #  |
-    when 10;return getarray(s)                 # array
-    else;      return nil                                      # error
-    end
-  end
-
-  # ====================================================================
-  # AMF write subroutines
-
-  # -----      putdata         envelope data into AMF writeable form
-  # -----      encodevalue     pack variables as AMF
-
-  def putdata(index,n)
-    d =encodestring(index+"/onResult")
-    d+=encodestring("null")
-    d+=[-1].pack("N")
-    d+=encodevalue(n)
-  end
-
-  def encodevalue(n)
-    case n.class.to_s
-    when 'Array'
-      a=10.chr+encodelong(n.length)
-      n.each do |b|
-        a+=encodevalue(b)
-      end
-      a
-    when 'Hash'
-      a=3.chr
-      n.each do |k,v|
-        a+=encodestring(k)+encodevalue(v)
-      end
-      a+0.chr+0.chr+9.chr
-    when 'String'
-      2.chr+encodestring(n)
-    when 'Bignum','Fixnum','Float'
-      0.chr+encodedouble(n)
-    when 'NilClass'
-      5.chr
-    else
-      RAILS_DEFAULT_LOGGER.error("Unexpected Ruby type for AMF conversion: "+n.class.to_s)
-    end
-  end
-
-  # -----      encodestring    encode string with two-byte length
-  # -----      encodedouble    encode number as eight-byte double precision float
-  # -----      encodelong              encode number as four-byte long
-
-  def encodestring(n)
-    a,b=n.size.divmod(256)
-    a.chr+b.chr+n
-  end
-
-  def encodedouble(n)
-    [n].pack('G')
-  end
-
-  def encodelong(n)
-    [n].pack('N')
-  end
-
   # ====================================================================
   # Co-ordinate conversion
 
-  def lat2coord(a,basey,masterscale)
+  def lat2coord(a,basey,masterscale) #:doc:
     -(lat2y(a)-basey)*masterscale+250
   end
 
-  def long2coord(a,baselong,masterscale)
+  def long2coord(a,baselong,masterscale) #:doc:
     (a-baselong)*masterscale+350
   end
 
-  def lat2y(a)
+  def lat2y(a) #:doc:
     180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
   end
 
-  def coord2lat(a,masterscale,basey)
+  def coord2lat(a,masterscale,basey) #:doc:
     y2lat((a-250)/-masterscale+basey)
   end
 
-  def coord2long(a,masterscale,baselong)
+  def coord2long(a,masterscale,baselong) #:doc:
     (a-350)/masterscale+baselong
   end
 
index bf80499f7502e8a07d0355f2dbfe0b1b5b43962f..02d99f20c6095cca73e5138c70fb7a77e5aab37d 100644 (file)
@@ -70,6 +70,6 @@ Rails::Initializer.run do |config|
 end
 
 # This has to be after the above block for some reason (doesnt pull in /lib/osm.rb?)
-POTLATCH_PRESETS = OSM::Potlatch.get_presets()
+POTLATCH_PRESETS = Potlatch::Potlatch.get_presets()
 
 
index 6ec308173aba23601eeae4274f1cfc3244c33c58..129a6f24b58bb7a79f78f5f07dcaa1fc58e646ec 100644 (file)
@@ -1 +1,34 @@
 This is the OpenStreetMap rails server codebase. Documentation is currently extremely incomplete. Please help by writing docs and moving any SQL you see to use models etc.
+
+=INSTALL
+
+* Get rails working (http://www.rubyonrails.org/)
+* Make your db (see db/README)
+* Install ruby libxml bindings:
+    sudo apt-get install libxml-ruby1.8 libxml-parser-ruby1.8
+* Install primary keys plugin for active record (minimum version 0.9.1)
+    sudo gem install composite_primary_keys
+* Make sure you have a MTA listening on localhost:25 if you want mail
+    sudo apt-get install exim4
+* Start the server
+    script/server
+* Thats it
+
+=API CHANGES FOR EDITOR AUTHORS
+
+See
+
+http://wiki.openstreetmap.org/index.php/REST#Changes_in_the_upcoming_0.4_API
+
+=HACKING
+
+* Log in to your site (proably localhost:3000)
+* Create a user and confirm it
+* You want to play with the API (probably at http://localhost:3000/api/0.5/node/create etc)
+* Lots of tests are needed to test the API.
+* Lots of little things to make the site work like the old one.
+
+=Bugs
+
+See the 'rails_port' component for bugs:
+http://trac.openstreetmap.org/query?status=new&status=assigned&status=reopened&component=rails_port&order=priority
index 6e9346bb4f0076df8361c9a52b52348a8a426747..24df7a35ddf11efe5ea2aba1a83e8ee66cd4c7be 100644 (file)
@@ -279,7 +279,7 @@ module OSM
     def initialize(feed_title='OpenStreetMap GPS Traces', feed_description='OpenStreetMap GPS Traces', feed_url='http://www.openstreetmap.org/traces/')
       @doc = XML::Document.new
       @doc.encoding = 'UTF-8' 
-      
+
       rss = XML::Node.new 'rss'
       @doc.root = rss
       rss['version'] = "2.0"
@@ -425,72 +425,5 @@ module OSM
     return "#{tilesql} AND #{prefix}latitude BETWEEN #{minlat} AND #{maxlat} AND #{prefix}longitude BETWEEN #{minlon} AND #{maxlon}"
   end
 
-  class Potlatch # crazy shit
-
-    # ----- getpresets
-    #            in:   none
-    #            does: reads tag preset menus, colours, and autocomplete config files
-    #        out:  [0] presets, [1] presetmenus, [2] presetnames,
-    #                          [3] colours, [4] casing, [5] areas, [6] autotags
-    #                          (all hashes)
-    def self.get_presets
-      RAILS_DEFAULT_LOGGER.info("  Message: getpresets")
-
-      # Read preset menus
-      presets={}
-      presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[]; presetmenus['POI']=[]
-      presetnames={}; presetnames['point']={}; presetnames['way']={}; presetnames['POI']={}
-      presettype=''
-      presetcategory=''
-      #        StringIO.open(txt) do |file|
-      File.open("#{RAILS_ROOT}/config/potlatch/presets.txt") do |file|
-        file.each_line {|line|
-          t=line.chomp
-          if (t=~/(\w+)\/(\w+)/) then
-            presettype=$1
-            presetcategory=$2
-            presetmenus[presettype].push(presetcategory)
-            presetnames[presettype][presetcategory]=["(no preset)"]
-          elsif (t=~/^(.+):\s?(.+)$/) then
-            pre=$1; kv=$2
-            presetnames[presettype][presetcategory].push(pre)
-            presets[pre]={}
-            kv.split(',').each {|a|
-              if (a=~/^(.+)=(.*)$/) then presets[pre][$1]=$2 end
-            }
-          end
-        }
-      end
-
-      # Read colours/styling
-      colours={}; casing={}; areas={}
-      File.open("#{RAILS_ROOT}/config/potlatch/colours.txt") do |file|
-        file.each_line {|line|
-          t=line.chomp
-          if (t=~/(\w+)\s+([^\s]+)\s+([^\s]+)\s+([^\s]+)/) then
-            tag=$1
-            if ($2!='-') then colours[tag]=$2.hex end
-            if ($3!='-') then casing[tag]=$3.hex end
-            if ($4!='-') then areas[tag]=$4.hex end
-          end
-        }
-      end
-
-      # Read auto-complete
-      autotags={}; autotags['point']={}; autotags['way']={}; autotags['POI']={};
-      File.open("#{RAILS_ROOT}/config/potlatch/autocomplete.txt") do |file|
-        file.each_line {|line|
-          t=line.chomp
-          if (t=~/^(\w+)\/(\w+)\s+(.+)$/) then
-            tag=$1; type=$2; values=$3
-            if values=='-' then autotags[type][tag]=[]
-            else autotags[type][tag]=values.split(',').sort.reverse end
-          end
-        }
-      end
-
-      [presets,presetmenus,presetnames,colours,casing,areas,autotags]
-    end
-  end
 
 end
diff --git a/lib/potlatch.rb b/lib/potlatch.rb
new file mode 100644 (file)
index 0000000..b2f8eb4
--- /dev/null
@@ -0,0 +1,189 @@
+# The Potlatch module provides helper functions for potlatch and its communication with the server
+module Potlatch
+
+  # The AMF class is a set of helper functions for encoding and decoding AMF.
+  class AMF
+    
+    # Return two-byte integer
+    def self.getint(s) 
+      s.getc*256+s.getc
+    end
+
+    # Return four-byte long
+    def self.getlong(s) 
+      ((s.getc*256+s.getc)*256+s.getc)*256+s.getc
+    end
+
+    # Return string with two-byte length 
+    def self.getstring(s) 
+      len=s.getc*256+s.getc
+      s.read(len)
+    end
+
+    # Return eight-byte double-precision float 
+    def self.getdouble(s) 
+      a=s.read(8).unpack('G')                  # G big-endian, E little-endian
+      a[0]
+    end
+
+    # Return numeric array
+    def self.getarray(s) 
+      len=getlong(s)
+      arr=[]
+      for i in (0..len-1)
+        arr[i]=getvalue(s)
+      end
+      arr
+    end
+
+    # Return object/hash 
+    def self.getobject(s) 
+      arr={}
+      while (key=getstring(s))
+        if (key=='') then break end
+        arr[key]=getvalue(s)
+      end
+      s.getc           # skip the 9 'end of object' value
+      arr
+    end
+
+    # Parse and get value
+    def self.getvalue(s) 
+      case s.getc
+      when 0;  return getdouble(s)                     # number
+      when 1;  return s.getc                           # boolean
+      when 2;  return getstring(s)                     # string
+      when 3;  return getobject(s)                     # object/hash
+      when 5;  return nil                                      # null
+      when 6;  return nil                                      # undefined
+      when 8;  s.read(4)                                       # mixedArray
+        return getobject(s)                    #  |
+      when 10;return getarray(s)                       # array
+      else;    return nil                                      # error
+      end
+    end
+
+    # Envelope data into AMF writeable form
+    def self.putdata(index,n) 
+      d =encodestring(index+"/onResult")
+      d+=encodestring("null")
+      d+=[-1].pack("N")
+      d+=encodevalue(n)
+    end
+
+    # Pack variables as AMF
+    def self.encodevalue(n) 
+      case n.class.to_s
+      when 'Array'
+        a=10.chr+encodelong(n.length)
+        n.each do |b|
+          a+=encodevalue(b)
+        end
+        a
+      when 'Hash'
+        a=3.chr
+        n.each do |k,v|
+          a+=encodestring(k)+encodevalue(v)
+        end
+        a+0.chr+0.chr+9.chr
+      when 'String'
+        2.chr+encodestring(n)
+      when 'Bignum','Fixnum','Float'
+        0.chr+encodedouble(n)
+      when 'NilClass'
+        5.chr
+      else
+        RAILS_DEFAULT_LOGGER.error("Unexpected Ruby type for AMF conversion: "+n.class.to_s)
+      end
+    end
+
+    # Encode string with two-byte length
+    def self.encodestring(n) 
+      a,b=n.size.divmod(256)
+      a.chr+b.chr+n
+    end
+
+    # Encode number as eight-byte double precision float 
+    def self.encodedouble(n) 
+      [n].pack('G')
+    end
+
+    # Encode number as four-byte long
+    def self.encodelong(n) 
+      [n].pack('N')
+    end
+
+  end
+
+
+  # The Potlatch class is a helper for Potlatch
+  class Potlatch
+
+    # ----- getpresets
+    #            in:   none
+    #            does: reads tag preset menus, colours, and autocomplete config files
+    #        out:  [0] presets, [1] presetmenus, [2] presetnames,
+    #                          [3] colours, [4] casing, [5] areas, [6] autotags
+    #                          (all hashes)
+    def self.get_presets
+      RAILS_DEFAULT_LOGGER.info("  Message: getpresets")
+
+      # Read preset menus
+      presets={}
+      presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[]; presetmenus['POI']=[]
+      presetnames={}; presetnames['point']={}; presetnames['way']={}; presetnames['POI']={}
+      presettype=''
+      presetcategory=''
+      #        StringIO.open(txt) do |file|
+      File.open("#{RAILS_ROOT}/config/potlatch/presets.txt") do |file|
+        file.each_line {|line|
+          t=line.chomp
+          if (t=~/(\w+)\/(\w+)/) then
+            presettype=$1
+            presetcategory=$2
+            presetmenus[presettype].push(presetcategory)
+            presetnames[presettype][presetcategory]=["(no preset)"]
+          elsif (t=~/^(.+):\s?(.+)$/) then
+            pre=$1; kv=$2
+            presetnames[presettype][presetcategory].push(pre)
+            presets[pre]={}
+            kv.split(',').each {|a|
+              if (a=~/^(.+)=(.*)$/) then presets[pre][$1]=$2 end
+            }
+          end
+        }
+      end
+
+      # Read colours/styling
+      colours={}; casing={}; areas={}
+      File.open("#{RAILS_ROOT}/config/potlatch/colours.txt") do |file|
+        file.each_line {|line|
+          t=line.chomp
+          if (t=~/(\w+)\s+([^\s]+)\s+([^\s]+)\s+([^\s]+)/) then
+            tag=$1
+            if ($2!='-') then colours[tag]=$2.hex end
+            if ($3!='-') then casing[tag]=$3.hex end
+            if ($4!='-') then areas[tag]=$4.hex end
+          end
+        }
+      end
+
+      # Read auto-complete
+      autotags={}; autotags['point']={}; autotags['way']={}; autotags['POI']={};
+      File.open("#{RAILS_ROOT}/config/potlatch/autocomplete.txt") do |file|
+        file.each_line {|line|
+          t=line.chomp
+          if (t=~/^(\w+)\/(\w+)\s+(.+)$/) then
+            tag=$1; type=$2; values=$3
+            if values=='-' then autotags[type][tag]=[]
+            else autotags[type][tag]=values.split(',').sort.reverse end
+          end
+        }
+      end
+
+      [presets,presetmenus,presetnames,colours,casing,areas,autotags]
+    end
+  end
+
+end
+