Added a query method for querying bounding boxes, times and users of changesets. Needs (much) more testing.

app/controllers/changeset_controller.rb

@@ -6,9 +6,12 @@ class ChangesetController < ApplicationController
 
   before_filter :authorize, :only => [:create, :update, :delete, :upload, :include]
   before_filter :check_write_availability, :only => [:create, :update, :delete, :upload, :include]
-  before_filter :check_read_availability, :except => [:create, :update, :delete, :upload, :download]
+  before_filter :check_read_availability, :except => [:create, :update, :delete, :upload, :download, :query]
   after_filter :compress_output
 
+  # Help methods for checking boundary sanity and area size
+  include MapBoundary
+
   # Create a changeset from XML.
   def create
     if request.put?
@@ -224,4 +227,104 @@ class ChangesetController < ApplicationController
     render ex.render_opts
   end
 
+  ##
+  # query changesets by bounding box, time, user or open/closed status.
+  def query
+    # create the conditions that the user asked for. some or all of
+    # these may be nil.
+    conditions = conditions_bbox(params['bbox'])
+    cond_merge conditions, conditions_user(params['user'])
+    cond_merge conditions, conditions_time(params['time'])
+    cond_merge conditions, conditions_open(params['open'])
+
+    # create the results document
+    results = OSM::API.new.get_xml_doc
+
+    # add all matching changesets to the XML results document
+    Changeset.find(:all, 
+                   :conditions => conditions, 
+                   :limit => 100,
+                   :order => 'created_at desc').each do |cs|
+      results.root << cs.to_xml_node
+    end
+
+    render :text => results.to_s, :content_type => "text/xml"
+
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  rescue String => s
+    render :text => s, :content_type => "text/plain", :status => :bad_request
+  end
+
+  ##
+  # merge two conditions
+  def cond_merge(a, b)
+    if a and b
+      a_str = a.shift
+      b_str = b.shift
+      return [ a_str + " and " + b_str ] + a + b
+    elsif a 
+      return a
+    else b
+      return b
+    end
+  end
+
+  ##
+  # if a bounding box was specified then parse it and do some sanity 
+  # checks. this is mostly the same as the map call, but without the 
+  # area restriction.
+  def conditions_bbox(bbox)
+    unless bbox.nil?
+      raise "Bounding box should be min_lon,min_lat,max_lon,max_lat" unless bbox.count(',') == 3
+      bbox = sanitise_boundaries(bbox.split(/,/))
+      raise "Minimum longitude should be less than maximum." unless bbox[0] <= bbox[2]
+      raise "Minimum latitude should be less than maximum." unless bbox[1] <= bbox[3]
+      return ['min_lon < ? and max_lon > ? and min_lat < ? and max_lat > ?',
+              bbox[2] * SCALE, bbox[0] * SCALE, bbox[3]* SCALE, bbox[1] * SCALE]
+    else
+      return nil
+    end
+  end
+
+  ##
+  # restrict changesets to those by a particular user
+  def conditions_user(user)
+    unless user.nil?
+      u = User.find(user.to_i)
+      raise OSM::APINotFoundError unless u.data_public?
+      return ['user_id = ?', u.id]
+    else
+      return nil
+    end
+  end
+
+  ##
+  # restrict changes to those during a particular time period
+  def conditions_time(time) 
+    unless time.nil?
+      # if there is a range, i.e: comma separated, then the first is 
+      # low, second is high - same as with bounding boxes.
+      if time.count(',') == 1
+        from, to = time.split(/,/).collect { |t| Date.parse(t) }
+        return ['created_at > ? and created_at < ?', from, to]
+      else
+        # if there is no comma, assume its a lower limit on time
+        return ['created_at > ?', Date.parse(time)]
+      end
+    else
+      return nil
+    end
+  rescue ArgumentError => ex
+    raise ex.message.to_s
+  end
+
+  ##
+  # restrict changes to those which are open
+  def conditions_open(open)
+    return open.nil? ? nil : ['open = ?', true]
+  end
+
 end

app/models/node.rb

@@ -83,7 +83,7 @@ class Node < ActiveRecord::Base
 
     # version must be present unless creating
     return nil unless create or not pt['version'].nil?
-    node.version = pt['version'].to_i
+    node.version = create ? 0 : pt['version'].to_i
 
     unless create
       if pt['id'] != '0'

test/fixtures/changesets.yml

@@ -1,9 +1,17 @@
+# FIXME! all of these changesets need their bounding boxes set correctly!
+# 
+<% SCALE = 10000000 unless defined?(SCALE) %>
+
 # Read about fixtures at http://ar.rubyonrails.org/classes/Fixtures.html
 normal_user_first_change:
   id: 1
   user_id: 1
   created_at: "2007-01-01 00:00:00"
   open: true
+  min_lon: <%= 1 * SCALE %>
+  min_lat: <%= 1 * SCALE %>
+  max_lon: <%= 5 * SCALE %>
+  max_lat: <%= 5 * SCALE %>
   
 second_user_first_change:
   id: 2
@@ -22,3 +30,12 @@ normal_user_version_change:
   user_id: 1
   created_at: "2008-01-01 00:00:00"
   open: true
+
+# changeset to contain all the invalid stuff that is in the
+# fixtures (nodes outside the world, etc...)
+invalid_changeset:
+  id: 5
+  user_id: 0
+  created_at: "2008-01-01 00:00:00"
+  open: false
+  

test/fixtures/current_nodes.yml

@@ -55,7 +55,7 @@ node_too_far_north:
   id: 6
   latitude: <%= 90.01*SCALE %>
   longitude: <%= 6*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(90.01,6) %>
@@ -65,7 +65,7 @@ node_north_limit:
   id: 11
   latitude: <%= 90*SCALE %>
   longitude: <%= 11*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(90,11) %>
@@ -75,7 +75,7 @@ node_too_far_south:
   id: 7
   latitude: <%= -90.01*SCALE %>
   longitude: <%= 7*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(-90.01,7) %>
@@ -85,7 +85,7 @@ node_south_limit:
   id: 12
   latitude: <%= -90*SCALE %>
   longitude: <%= 12*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(-90,12) %>
@@ -95,7 +95,7 @@ node_too_far_west:
   id: 8
   latitude: <%= 8*SCALE %>
   longitude: <%= -180.01*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(8,-180.01) %>
@@ -105,7 +105,7 @@ node_west_limit:
   id: 13
   latitude: <%= 13*SCALE %>
   longitude: <%= -180*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(13,-180) %>
@@ -115,7 +115,7 @@ node_too_far_east:
   id: 9
   latitude: <%= 9*SCALE %>
   longitude: <%= 180.01*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(9,180.01) %>
@@ -125,7 +125,7 @@ node_east_limit:
   id: 14
   latitude: <%= 14*SCALE %>
   longitude: <%= 180*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(14,180) %>
@@ -135,7 +135,7 @@ node_totally_wrong:
   id: 10
   latitude: <%= 200*SCALE %>
   longitude: <%= 200*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(200,200) %>

test/fixtures/nodes.yml

@@ -55,7 +55,7 @@ node_too_far_north:
   id: 6
   latitude: <%= 90.01*SCALE %>
   longitude: <%= 6*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(90.01,6) %>
@@ -65,7 +65,7 @@ node_north_limit:
   id: 11
   latitude: <%= 90*SCALE %>
   longitude: <%= 11*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(90,11) %>
@@ -75,7 +75,7 @@ node_too_far_south:
   id: 7
   latitude: <%= -90.01*SCALE %>
   longitude: <%= 7*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(-90.01,7) %>
@@ -85,7 +85,7 @@ node_south_limit:
   id: 12
   latitude: <%= -90*SCALE %>
   longitude: <%= 12*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(-90,12) %>
@@ -95,7 +95,7 @@ node_too_far_west:
   id: 8
   latitude: <%= 8*SCALE %>
   longitude: <%= -180.01*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(8,-180.01) %>
@@ -105,7 +105,7 @@ node_west_limit:
   id: 13
   latitude: <%= 13*SCALE %>
   longitude: <%= -180*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(13,-180) %>
@@ -115,7 +115,7 @@ node_too_far_east:
   id: 9
   latitude: <%= 9*SCALE %>
   longitude: <%= 180.01*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(9,180.01) %>
@@ -125,7 +125,7 @@ node_east_limit:
   id: 14
   latitude: <%= 14*SCALE %>
   longitude: <%= 180*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(14,180) %>
@@ -135,7 +135,7 @@ node_totally_wrong:
   id: 10
   latitude: <%= 200*SCALE %>
   longitude: <%= 200*SCALE %>
-  changeset_id: 1
+  changeset_id: 5
   visible: true
   version: 1
   tile: <%= QuadTile.tile_for_point(200,200) %>

test/functional/changeset_controller_test.rb

@@ -576,6 +576,14 @@ EOF
     check_after_include(changeset_id, -2,  5, [-2, -1,  4,  5])
   end
 
+  ##
+  # check searching for changesets by bbox
+  def test_changeset_by_bbox
+    get :query, :bbox => "-10,-10, 10, 10"
+    assert_response :success, "can't get changesets in bbox"
+    # FIXME: write the actual test bit after fixing the fixtures!
+  end
+
   #------------------------------------------------------------
   # utility functions
   #------------------------------------------------------------