source: subversion/sites/rails_port/lib/osm.rb @ 15156

Last change on this file since 15156 was 15156, checked in by zere, 10 years ago

Fixed typo.

File size: 11.3 KB
Line 
1# The OSM module provides support functions for OSM.
2module OSM
3
4  require 'time'
5  require 'rexml/parsers/sax2parser'
6  require 'rexml/text'
7  require 'xml/libxml'
8  require 'digest/md5'
9  require 'RMagick'
10
11  # The base class for API Errors.
12  class APIError < RuntimeError
13    def status
14      :internal_server_error
15    end
16
17    def to_s
18      "Generic API Error"
19    end
20  end
21
22  # Raised when an API object is not found.
23  class APINotFoundError < APIError
24    def status
25      :not_found
26    end
27
28    def to_s
29      "Object not found"
30    end
31  end
32
33  # Raised when a precondition to an API action fails sanity check.
34  class APIPreconditionFailedError < APIError
35    def initialize(message = "")
36      @message = message
37    end
38
39    def status
40      :precondition_failed   
41    end
42
43    def to_s
44      "Precondition failed: #{@message}"
45    end
46  end
47
48  # Raised when to delete an already-deleted object.
49  class APIAlreadyDeletedError < APIError
50    def initialize(object = "object", object_id = "")
51      @object, @object_id = object, object_id
52    end
53   
54    attr_reader :object, :object_id
55
56    def status
57      :gone
58    end
59   
60    def to_s
61      "The #{object} with the id #{object_id} has already been deleted"
62    end
63  end
64
65  # Raised when the user logged in isn't the same as the changeset
66  class APIUserChangesetMismatchError < APIError
67    def status
68      :conflict
69    end
70
71    def to_s
72      "The user doesn't own that changeset"
73    end
74  end
75
76  # Raised when the changeset provided is already closed
77  class APIChangesetAlreadyClosedError < APIError
78    def initialize(changeset)
79      @changeset = changeset
80    end
81
82    attr_reader :changeset
83
84    def status
85      :conflict
86    end
87
88    def to_s
89      "The changeset #{@changeset.id} was closed at #{@changeset.closed_at}"
90    end
91  end
92 
93  # Raised when a change is expecting a changeset, but the changeset doesn't exist
94  class APIChangesetMissingError < APIError
95    def status
96      :conflict
97    end
98
99    def to_s
100      "You need to supply a changeset to be able to make a change"
101    end
102  end
103
104  # Raised when a diff is uploaded containing many changeset IDs which don't match
105  # the changeset ID that the diff was uploaded to.
106  class APIChangesetMismatchError < APIError
107    def initialize(provided, allowed)
108      @provided, @allowed = provided, allowed
109    end
110
111    def status
112      :conflict
113    end
114
115    def to_s
116      "Changeset mismatch: Provided #{@provided} but only #{@allowed} is allowed"
117    end
118  end
119 
120  # Raised when a diff upload has an unknown action. You can only have create,
121  # modify, or delete
122  class APIChangesetActionInvalid < APIError
123    def initialize(provided)
124      @provided = provided
125    end
126
127    def status
128      :bad_request
129    end
130   
131    def to_s
132      "Unknown action #{@provided}, choices are create, modify, delete"
133    end
134  end
135
136  # Raised when bad XML is encountered which stops things parsing as
137  # they should.
138  class APIBadXMLError < APIError
139    def initialize(model, xml, message="")
140      @model, @xml, @message = model, xml, message
141    end
142
143    def status
144      :bad_request
145    end
146
147    def to_s
148      "Cannot parse valid #{@model} from xml string #{@xml}. #{@message}"
149    end
150  end
151
152  # Raised when the provided version is not equal to the latest in the db.
153  class APIVersionMismatchError < APIError
154    def initialize(id, type, provided, latest)
155      @id, @type, @provided, @latest = id, type, provided, latest
156    end
157
158    attr_reader :provided, :latest, :id, :type
159
160    def status
161      :conflict
162    end
163
164    def to_s
165      "Version mismatch: Provided #{provided}, server had: #{latest} of #{type} #{id}"
166    end
167  end
168
169  # raised when a two tags have a duplicate key string in an element.
170  # this is now forbidden by the API.
171  class APIDuplicateTagsError < APIError
172    def initialize(type, id, tag_key)
173      @type, @id, @tag_key = type, id, tag_key
174    end
175
176    attr_reader :type, :id, :tag_key
177
178    def status
179      :bad_request
180    end
181
182    def to_s
183      "Element #{@type}/#{@id} has duplicate tags with key #{@tag_key}"
184    end
185  end
186 
187  # Raised when a way has more than the configured number of way nodes.
188  # This prevents ways from being to long and difficult to work with
189  class APITooManyWayNodesError < APIError
190    def initialize(provided, max)
191      @provided, @max = provided, max
192    end
193   
194    attr_reader :provided, :max
195
196    def status
197      :bad_request
198    end
199   
200    def to_s
201      "You tried to add #{provided} nodes to the way, however only #{max} are allowed"
202    end
203  end
204
205  ##
206  # raised when user input couldn't be parsed
207  class APIBadUserInput < APIError
208    def initialize(message)
209      @message = message
210    end
211
212    def status
213      :bad_request
214    end
215
216    def to_s
217      @message
218    end
219  end
220
221  ##
222  # raised when an API call is made using a method not supported on that URI
223  class APIBadMethodError < APIError
224    def initialize(supported_method)
225      @supported_method = supported_method
226    end
227
228    def status
229      :method_not_allowed
230    end
231
232    def to_s
233      "Only method #{@supported_method} is supported on this URI"
234    end
235  end
236
237  ##
238  # raised when an API call takes too long
239  class APITimeoutError < APIError
240    def status
241      :request_timeout
242    end
243
244    def to_s
245      "Request timed out"
246    end
247  end
248
249  # Helper methods for going to/from mercator and lat/lng.
250  class Mercator
251    include Math
252
253    #init me with your bounding box and the size of your image
254    def initialize(min_lat, min_lon, max_lat, max_lon, width, height)
255      xsize = xsheet(max_lon) - xsheet(min_lon)
256      ysize = ysheet(max_lat) - ysheet(min_lat)
257      xscale = xsize / width
258      yscale = ysize / height
259      scale = [xscale, yscale].max
260
261      xpad = width * scale - xsize
262      ypad = height * scale - ysize
263
264      @width = width
265      @height = height
266
267      @tx = xsheet(min_lon) - xpad / 2
268      @ty = ysheet(min_lat) - ypad / 2
269
270      @bx = xsheet(max_lon) + xpad / 2
271      @by = ysheet(max_lat) + ypad / 2
272    end
273
274    #the following two functions will give you the x/y on the entire sheet
275
276    def ysheet(lat)
277      log(tan(PI / 4 + (lat * PI / 180 / 2))) / (PI / 180)
278    end
279
280    def xsheet(lon)
281      lon
282    end
283
284    #and these two will give you the right points on your image. all the constants can be reduced to speed things up. FIXME
285
286    def y(lat)
287      return @height - ((ysheet(lat) - @ty) / (@by - @ty) * @height)
288    end
289
290    def x(lon)
291      return  ((xsheet(lon) - @tx) / (@bx - @tx) * @width)
292    end
293  end
294
295  class GreatCircle
296    include Math
297
298    # initialise with a base position
299    def initialize(lat, lon)
300      @lat = lat * PI / 180
301      @lon = lon * PI / 180
302    end
303
304    # get the distance from the base position to a given position
305    def distance(lat, lon)
306      lat = lat * PI / 180
307      lon = lon * PI / 180
308      return 6372.795 * 2 * asin(sqrt(sin((lat - @lat) / 2) ** 2 + cos(@lat) * cos(lat) * sin((lon - @lon)/2) ** 2))
309    end
310
311    # get the worst case bounds for a given radius from the base position
312    def bounds(radius)
313      latradius = 2 * asin(sqrt(sin(radius / 6372.795 / 2) ** 2))
314      lonradius = 2 * asin(sqrt(sin(radius / 6372.795 / 2) ** 2 / cos(@lat) ** 2))
315      minlat = (@lat - latradius) * 180 / PI
316      maxlat = (@lat + latradius) * 180 / PI
317      minlon = (@lon - lonradius) * 180 / PI
318      maxlon = (@lon + lonradius) * 180 / PI
319      return { :minlat => minlat, :maxlat => maxlat, :minlon => minlon, :maxlon => maxlon }
320    end
321  end
322
323  class GeoRSS
324    def initialize(feed_title='OpenStreetMap GPS Traces', feed_description='OpenStreetMap GPS Traces', feed_url='http://www.openstreetmap.org/traces/')
325      @doc = XML::Document.new
326      @doc.encoding = XML::Encoding::UTF_8
327
328      rss = XML::Node.new 'rss'
329      @doc.root = rss
330      rss['version'] = "2.0"
331      rss['xmlns:geo'] = "http://www.w3.org/2003/01/geo/wgs84_pos#"
332      @channel = XML::Node.new 'channel'
333      rss << @channel
334      title = XML::Node.new 'title'
335      title <<  feed_title
336      @channel << title
337      description_el = XML::Node.new 'description'
338      @channel << description_el
339
340      description_el << feed_description
341      link = XML::Node.new 'link'
342      link << feed_url
343      @channel << link
344      image = XML::Node.new 'image'
345      @channel << image
346      url = XML::Node.new 'url'
347      url << 'http://www.openstreetmap.org/images/mag_map-rss2.0.png'
348      image << url
349      title = XML::Node.new 'title'
350      title << "OpenStreetMap"
351      image << title
352      width = XML::Node.new 'width'
353      width << '100'
354      image << width
355      height = XML::Node.new 'height'
356      height << '100'
357      image << height
358      link = XML::Node.new 'link'
359      link << feed_url
360      image << link
361    end
362
363    def add(latitude=0, longitude=0, title_text='dummy title', author_text='anonymous', url='http://www.example.com/', description_text='dummy description', timestamp=DateTime.now)
364      item = XML::Node.new 'item'
365
366      title = XML::Node.new 'title'
367      item << title
368      title << title_text
369      link = XML::Node.new 'link'
370      link << url
371      item << link
372
373      guid = XML::Node.new 'guid'
374      guid << url
375      item << guid
376
377      description = XML::Node.new 'description'
378      description << description_text
379      item << description
380
381      author = XML::Node.new 'author'
382      author << author_text
383      item << author
384
385      pubDate = XML::Node.new 'pubDate'
386      pubDate << timestamp.to_s(:rfc822)
387      item << pubDate
388
389      if latitude
390        lat_el = XML::Node.new 'geo:lat'
391        lat_el << latitude.to_s
392        item << lat_el
393      end
394
395      if longitude
396        lon_el = XML::Node.new 'geo:long'
397        lon_el << longitude.to_s
398        item << lon_el
399      end
400
401      @channel << item
402    end
403
404    def to_s
405      return @doc.to_s
406    end
407  end
408
409  class API
410    def get_xml_doc
411      doc = XML::Document.new
412      doc.encoding = XML::Encoding::UTF_8
413      root = XML::Node.new 'osm'
414      root['version'] = API_VERSION
415      root['generator'] = GENERATOR
416      doc.root = root
417      return doc
418    end
419  end
420
421  def self.IPLocation(ip_address)
422    Timeout::timeout(4) do
423      Net::HTTP.start('api.hostip.info') do |http|
424        country = http.get("/country.php?ip=#{ip_address}").body
425        country = "GB" if country == "UK"
426        country = Country.find_by_code(country)
427        return { :minlon => country.min_lon, :minlat => country.min_lat, :maxlon => country.max_lon, :maxlat => country.max_lat }
428      end
429    end
430
431    return nil
432  rescue Exception
433    return nil
434  end
435
436  # Construct a random token of a given length
437  def self.make_token(length = 30)
438    chars = 'abcdefghijklmnopqrtuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
439    token = ''
440
441    length.times do
442      token += chars[(rand * chars.length).to_i].chr
443    end
444
445    return token
446  end
447
448  # Return an encrypted version of a password
449  def self.encrypt_password(password, salt)
450    return Digest::MD5.hexdigest(password) if salt.nil?
451    return Digest::MD5.hexdigest(salt + password)
452  end
453
454  # Return an SQL fragment to select a given area of the globe
455  def self.sql_for_area(minlat, minlon, maxlat, maxlon, prefix = nil)
456    tilesql = QuadTile.sql_for_area(minlat, minlon, maxlat, maxlon, prefix)
457    minlat = (minlat * 10000000).round
458    minlon = (minlon * 10000000).round
459    maxlat = (maxlat * 10000000).round
460    maxlon = (maxlon * 10000000).round
461
462    return "#{tilesql} AND #{prefix}latitude BETWEEN #{minlat} AND #{maxlat} AND #{prefix}longitude BETWEEN #{minlon} AND #{maxlon}"
463  end
464
465
466end
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