pass common API error text through to Potlatch so it can be shown to the user

app/controllers/amf_controller.rb

@@ -220,7 +220,7 @@ class AmfController < ApplicationController
     [0, ways, points, relations]
 
   rescue Exception => err
-    [-2,"Sorry - I can't get the map for that area."]
+    [-2,"Sorry - I can't get the map for that area. The server said: #{err}"]
   end
 
   # Find deleted ways in current bounding box (similar to whichways, but ways
@@ -236,7 +236,7 @@ class AmfController < ApplicationController
     begin
       check_boundaries(xmin, ymin, xmax, ymax)
     rescue Exception => err
-      return [-2,"Sorry - I can't get the map for that area."]
+      return [-2,"Sorry - I can't get the map for that area. The server said: #{err}"]
     end
 
     nodes_in_area = Node.find_by_area(ymin, xmin, ymax, xmax, :conditions => ["current_ways.visible = ?", false], :include => :ways_via_history)
@@ -515,12 +515,12 @@ class AmfController < ApplicationController
     # Really need to check to see whether this is a server load issue, and the 
     # last version was in the same changeset, or belongs to the same user, then
     # we can return something different
-    return [-3, "Sorry, someone else has changed this relation since you started editing. Please click the 'Edit' tab to reload the area."]
+    return [-3, "Sorry, someone else has changed this relation since you started editing. Please click the 'Edit' tab to reload the area. The server said: #{ex}"]
   rescue OSM::APIAlreadyDeletedError => ex
     return [-1, "The relation has already been deleted."]
   rescue OSM::APIError => ex
     # Some error that we don't specifically catch
-    return [-2, "An unusual error happened (in 'putrelation' #{relid})."]
+    return [-2, "An unusual error happened (in 'putrelation' #{relid}). The server said: #{ex}"]
   end
 
   # Save a way to the database, including all nodes. Any nodes in the previous
@@ -637,14 +637,14 @@ class AmfController < ApplicationController
     # Really need to check to see whether this is a server load issue, and the 
     # last version was in the same changeset, or belongs to the same user, then
     # we can return something different
-    return [-3, "Sorry, someone else has changed this way since you started editing. Please click the 'Edit' tab to reload the area."]
+    return [-3, "Sorry, someone else has changed this way since you started editing. Click the 'Edit' tab to reload the area. The server said: #{ex}"]
   rescue OSM::APITooManyWayNodesError => ex
     return [-1, "You have tried to upload a really long way with #{ex.provided} points: only #{ex.max} are allowed."]
   rescue OSM::APIAlreadyDeletedError => ex
     return [-1, "The point has already been deleted."]
   rescue OSM::APIError => ex
     # Some error that we don't specifically catch
-    return [-2, "An unusual error happened (in 'putway' #{originalway})."]
+    return [-2, "An unusual error happened (in 'putway' #{originalway}). The server said: #{ex}"]
   end
 
   # Save POI to the database.
@@ -702,12 +702,12 @@ class AmfController < ApplicationController
     # Really need to check to see whether this is a server load issue, and the 
     # last version was in the same changeset, or belongs to the same user, then
     # we can return something different
-    return [-3, "Sorry, someone else has changed this point since you started editing. Please click the 'Edit' tab to reload the area."]
+    return [-3, "Sorry, someone else has changed this point since you started editing. Please click the 'Edit' tab to reload the area. The server said: #{ex}"]
   rescue OSM::APIAlreadyDeletedError => ex
     return [-1, "The point has already been deleted"]
   rescue OSM::APIError => ex
     # Some error that we don't specifically catch
-    return [-2, "An unusual error happened (in 'putpoi' #{id})."]
+    return [-2, "An unusual error happened (in 'putpoi' #{id}). The server said: #{ex}"]
   end
 
   # Read POI from database
@@ -783,7 +783,7 @@ class AmfController < ApplicationController
     return [-1, "The way has already been deleted."]
   rescue OSM::APIError => ex
     # Some error that we don't specifically catch
-    return [-2, "An unusual error happened (in 'deleteway' #{way_id})."]
+    return [-2, "An unusual error happened (in 'deleteway' #{way_id}). The server said: #{ex}"]
   end
 
 

lib/osm.rb

@@ -13,6 +13,10 @@ module OSM
     def render_opts
       { :text => "Generic API Error", :status => :internal_server_error, :content_type => "text/plain" }
     end
+
+    def to_s
+      "Generic API Error"
+    end
   end
 
   # Raised when an API object is not found.
@@ -31,6 +35,10 @@ module OSM
     def render_opts
       { :text => "Precondition failed: #{@message}", :status => :precondition_failed, :content_type => "text/plain" }
     end
+
+    def to_s
+      "Precondition failed: #{@message}"
+    end
   end
 
   # Raised when to delete an already-deleted object.
@@ -65,6 +73,10 @@ module OSM
     def render_opts
       { :text => "You need to supply a changeset to be able to make a change", :status => :conflict, :content_type => "text/plain" }
     end
+    
+    def to_s
+       "You need to supply a changeset to be able to make a change"
+    end
   end
 
   # Raised when a diff is uploaded containing many changeset IDs which don't match
@@ -119,6 +131,10 @@ module OSM
         ", server had: " + latest.to_s + " of " + type + " " + id.to_s, 
         :status => :conflict, :content_type => "text/plain" }
     end
+    
+    def to_s
+       "Version mismatch: Provided " + provided.to_s + ", server had: " + latest.to_s + " of " + type + " " + id.to_s
+    end
   end
 
   # raised when a two tags have a duplicate key string in an element.