Class: GeoModel

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
app/models/geo_model.rb

Direct Known Subclasses

SearchModel

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.area_field ⇒ Object 



37
38
39
 
# File 'app/models/geo_model.rb', line 37

def self.area_field
  "ST_Area(#{table_name}.#{geometry_column.name}) AS area"
end

.bbox_filter(params) ⇒ Object

based on mapfish_filter



105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
 
# File 'app/models/geo_model.rb', line 105

def self.bbox_filter(params)
  filter = scoped

  if params['bbox']
    x1, y1, x2, y2 = params['bbox'].split(',').collect(&:to_f)
    box = [[x1, y1], [x2, y2]]
    filter_geom = "'BOX3D(#{box[0].join(" ")},#{box[1].join(" ")})'::box3d"
  elsif params['polygon']
    filter_geom = "ST_GeomFromText('#{params['polygon']}')"
  end

  if filter_geom
    filter = filter.where("ST_Intersects(#{table_name}.#{connection.quote_column_name(geometry_column_name)}, ST_SetSRID(#{filter_geom}, #{srid}))")
  end

  filter.limit(1000)
end

.can_edit?(ability) ⇒ Boolean

Returns:

  • (Boolean) 


159
160
161
162
163
164
165
166
167
168
169
170
 
# File 'app/models/geo_model.rb', line 159

def self.can_edit?(ability)
  @layers ||= Layer.where(:table => self.table_name).all
  can_edit = false
  @layers.each do |layer|
    # check if any layer with this table is editable
    if ability.can?(:edit, layer)
      can_edit = true
      break
    end
  end
  can_edit
end

.extent_field ⇒ Object 



33
34
35
 
# File 'app/models/geo_model.rb', line 33

def self.extent_field
  "ST_Envelope(#{table_name}.#{geometry_column_name}) AS extent"
end

.forbidden(ability) ⇒ Object 



184
185
186
187
188
189
190
191
 
# File 'app/models/geo_model.rb', line 184

def self.forbidden(ability)
  if ability.nil?
    logger.info "----> Edit access forbidden without login"
  else
    logger.info "----> Edit access forbidden with roles #{ability.roles.collect(&:name).join('+')}!"
  end
  where('1=0') # No access
end

.geo_factory ⇒ Object 



205
206
207
208
209
210
211
212
213
 
# File 'app/models/geo_model.rb', line 205

def self.geo_factory
  if self.rgeo_factory_generator == RGeo::ActiveRecord::DEFAULT_FACTORY_GENERATOR
    self.rgeo_factory_generator = RGeo::Geos.factory_generator
    rgeo_factory_settings.set_column_factory(table_name, geometry_column_name,
      RGeo::Cartesian.factory(:srid => 21781, :proj4 => '+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=600000 +y_0=200000 +ellps=bessel +towgs84=674.4,15.1,405.3,0,0,0,0 +units=m +no_defs')
    )
  end
  rgeo_factory_for_column(geometry_column_name)
end

.geojson_decode(json) ⇒ Object 



123
124
125
 
# File 'app/models/geo_model.rb', line 123

def self.geojson_decode(json)
  RGeo::GeoJSON.decode(json, :json_parser => :json, :geo_factory => geo_factory)
end

.geometry_column ⇒ Object 



27
28
29
30
31
 
# File 'app/models/geo_model.rb', line 27

def self.geometry_column
  col = columns_hash[geometry_column_name]
  col.instance_eval { @srid = srid }
  col
end

.geometry_column_info ⇒ Object 



8
9
10
11
12
13
 
# File 'app/models/geo_model.rb', line 8

def self.geometry_column_info
  #spatial_column_info returns key/value list with geometry_column name as key
  #value example: {:srid=>21781, :type=>"MULTIPOLYGON", :dimension=>2, :has_z=>false, :has_m=>false, :name=>"the_geom"}
  #We take the first matching entry
  @geometry_column_info ||= connection.spatial_column_info(table_name).values.first
end

.geometry_column_name ⇒ Object 



15
16
17
 
# File 'app/models/geo_model.rb', line 15

def self.geometry_column_name
  geometry_column_info[:name]
end

.geometry_type ⇒ Object 



19
20
21
 
# File 'app/models/geo_model.rb', line 19

def self.geometry_type
  geometry_column_info[:type]
end

.identify_filter(searchgeo, radius, nearest = false) ⇒ Object 



41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
 
# File 'app/models/geo_model.rb', line 41

def self.identify_filter(searchgeo, radius, nearest=false)
  filter = scoped
  if searchgeo[0..3] == "POLY"
    logger.debug "*** POLY-query: #{searchgeo} ***"
    polygon = "ST_GeomFromText('#{searchgeo}', #{srid})"
    filter = filter.where("ST_DWithin(#{table_name}.#{geometry_column_name}, #{polygon}, #{radius})")
    center = "ST_Centroid(#{polygon})"
  else
    if searchgeo.split(',').length == 3
      logger.debug "*** CIRCLE-query: #{searchgeo} ***"
      x1, y1, r  = searchgeo.split(',').collect(&:to_f)
      center = "ST_GeomFromText('POINT(#{x1} #{y1})', #{srid})"
      filter = filter.where("ST_DWithin(#{table_name}.#{geometry_column_name}, #{center}, #{r})")
    else
      logger.debug "*** BBOX-query: #{searchgeo} ***"
      x1, y1, x2, y2 = searchgeo.split(',').collect(&:to_f)
      center = "ST_GeomFromText('POINT(#{x1+(x2-x1)/2} #{y1+(y2-y1)/2})', #{srid})"
      filter = filter.where("ST_DWithin(#{table_name}.#{geometry_column_name}, #{center}, #{radius})")
    end
  end

  if nearest
    logger.debug "*** query nearest ***"
    min_dist = filter.select("Min(ST_Distance(#{table_name}.#{geometry_column_name}, #{center})) AS min_dist").first
    unless min_dist.nil?
      logger.debug "*** min_dist = #{min_dist.min_dist} ***"
      if min_dist.min_dist.to_f == 0
        # center of the search geometry is within a feature (may be overlapping features)
        filter = filter.where("ST_Within(#{center}, #{table_name}.#{geometry_column_name})")
      else
        # get the feature nearest to the center of the search geometry
        filter = filter.order("ST_Distance(#{table_name}.#{geometry_column_name}, #{center})").limit(1)
      end
    end
    # else no features in filter
  end

  filter
end

.srid ⇒ Object 



23
24
25
 
# File 'app/models/geo_model.rb', line 23

def self.srid
  geometry_column_info[:srid]
end

.user_filter(ability) ⇒ Object

apply user filter for editing Override in descendant classes



174
175
176
177
178
179
180
181
182
 
# File 'app/models/geo_model.rb', line 174

def self.user_filter(ability)
  if ability.nil?
    forbidden(ability)
  elsif can_edit?(ability)
    scoped #No filter
  else
    forbidden(ability)
  end
end

Instance Method Details

#bbox ⇒ Object

Custom identify query def self.identify_query(bbox, radius)

scoped.select().where()....

end



86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
 
# File 'app/models/geo_model.rb', line 86

def bbox
  if respond_to?('extent')
    # use extent from select(extent_field)
    envelope = GeoRuby::SimpleFeatures::Geometry.from_hex_ewkb(extent).envelope #TODO: replace with rgeo
    [envelope.lower_corner.x, envelope.lower_corner.y, envelope.upper_corner.x, envelope.upper_corner.y]
  else
    # get Box2D for this feature
    box_query = "Box2D(#{connection.quote_column_name(self.class.geometry_column_name)})"
    extent = self.class.select("ST_XMin(#{box_query}), ST_YMin(#{box_query}), ST_XMax(#{box_query}), ST_Ymax(#{box_query})").find(id)
    [
      extent.st_xmin.to_f,
      extent.st_ymin.to_f,
      extent.st_xmax.to_f,
      extent.st_ymax.to_f
    ]
  end
end

#csv_header ⇒ Object

header for CSV export



194
195
196
197
 
# File 'app/models/geo_model.rb', line 194

def csv_header
  #empty by default
  []
end

#csv_row ⇒ Object

row values for CSV export



200
201
202
203
 
# File 'app/models/geo_model.rb', line 200

def csv_row
  #empty by default
  []
end

#modified_by(user) ⇒ Object

update modification attributes (changed_by, etc.) Override in descendant classes



155
156
157
 
# File 'app/models/geo_model.rb', line 155

def modified_by(user)
  #none by default
end

#to_geojson(options = {}) ⇒ Object 



127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
 
# File 'app/models/geo_model.rb', line 127

def to_geojson(options = {})
  only = options.delete(:only)
  geoson = { :type => 'Feature' }
  geoson[:properties] = attributes.delete_if do |name, value|
    # TODO: support for multiple geometry columns
    if name == self.class.geometry_column_name
      geoson[:geometry] = value
      true
    elsif name == self.class.primary_key then
      geoson[:id] = value
      true
    elsif only
      !only.include?(name.to_sym)
    end
  end
  geoson.to_json
end

#update_attributes_from_geojson_feature(feature, user) ⇒ Object 



145
146
147
148
149
150
151
 
# File 'app/models/geo_model.rb', line 145

def update_attributes_from_geojson_feature(feature, user)
  attr = feature.properties
  attr[self.class.geometry_column_name] = feature.geometry unless feature.geometry.nil?
  ok = update_attributes(attr)
  modified_by(user)
  ok
end