Class: GoogleStaticMap

Inherits:
Object
  • Object
show all
Defined in:
lib/googlestaticmap.rb

Overview

Main class for creating a static map. Create an instance, Set attributes that describe properties of the map. Then call url to get a URL that you can use as the src of an img tag. You can also call get_map to actually download the map from Google, and optionally write it to a file.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(attrs = {}) ⇒ GoogleStaticMap

Takes an optional hash of attributes



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# File 'lib/googlestaticmap.rb', line 104

def initialize(attrs={})
  defaults = {:width => 500, :height => 350, :markers => [], :visible => [],
              :sensor => false, :maptype => "roadmap", :paths => [],
              :proxy_port => nil, :proxy_address => nil, :api_key => nil,
              :client_id => nil, :private_key => nil, :language => nil}

  attributes = defaults.merge(attrs)
  attributes.each {|k,v| self.send("#{k}=".to_sym,v)}
end

Instance Attribute Details

#api_key ⇒ Object

API Key - see developers.google.com/maps/documentation/static-maps/get-api-key#key for details Note that if this is set, you cannot provide a client ID



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# File 'lib/googlestaticmap.rb', line 72

def api_key
  @api_key
end

#center ⇒ Object

MapLocation for the center of the map. If this is not specified, the map will zoom to the markers



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# File 'lib/googlestaticmap.rb', line 33

def center
  @center
end

#channel ⇒ Object

Channel - identifier channel for tracking API source in enterprise tools

see https://developers.google.com/maps/documentation/business/clientside/quota for details



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# File 'lib/googlestaticmap.rb', line 87

def channel
  @channel
end

#client_id ⇒ Object

ClientId for business customers - see developers.google.com/maps/documentation/static-maps/get-api-key#key for details Note that if this is set, you cannot provide an API key.



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# File 'lib/googlestaticmap.rb', line 77

def client_id
  @client_id
end

#format ⇒ Object

format of the image:

  • png8 - 8 bit PNG (default)

  • png32 - 32 bit PNG

  • gif

  • jpg

  • jpg-baseline - non-progressive JPEG



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# File 'lib/googlestaticmap.rb', line 54

def format
  @format
end

#height ⇒ Object

Height of resulting image in pixels, defaults to 350, maximum 640



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# File 'lib/googlestaticmap.rb', line 20

def height
  @height
end

#language ⇒ Object

Language - :en, :ja

see https://developers.google.com/maps/documentation/static-maps/intro for details



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# File 'lib/googlestaticmap.rb', line 91

def language
  @language
end

#maptype ⇒ Object

Type of map to create:

  • roadmap (default)

  • satellite

  • terrain

  • hybrid - satellite imagery with roads



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# File 'lib/googlestaticmap.rb', line 61

def maptype
  @maptype
end

#markers ⇒ Object

An optional array of MapMarker instances



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# File 'lib/googlestaticmap.rb', line 23

def markers
  @markers
end

#paths ⇒ Object

An optional array of MapPath instances and/or MapPolygon instances to draw



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# File 'lib/googlestaticmap.rb', line 29

def paths
  @paths
end

#plain_string ⇒ Object

In case when some parameter should be inserted manually For example, using mapstyle.withgoogle.com/ tool and inserting generated style as is



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# File 'lib/googlestaticmap.rb', line 101

def plain_string
  @plain_string
end

#private_key ⇒ Object

The private key, also known as the URL signing secret, is used to to generate the signature parameter in the URL. This is required if you are using a client ID, or a premium API key, and is optional if you are using a standard API key. See developers.google.com/maps/documentation/static-maps/get-api-key for more details



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# File 'lib/googlestaticmap.rb', line 83

def private_key
  @private_key
end

#proxy_address ⇒ Object

If you need to use a proxy server to reach Google, set the name/address of the proxy server here



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# File 'lib/googlestaticmap.rb', line 65

def proxy_address
  @proxy_address
end

#proxy_port ⇒ Object

If proxy_address is set, set this to the port of the proxy server



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# File 'lib/googlestaticmap.rb', line 68

def proxy_port
  @proxy_port
end

#scale ⇒ Object

1, 2, or 4 for Maps API Premier customers. Defaults to 1. Makes everything in the image appear larger, useful for displaying on high res mobile screens. When setting this, the image’s actual width and height in pixels will be scale * width and scale * height



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# File 'lib/googlestaticmap.rb', line 46

def scale
  @scale
end

#sensor ⇒ Object

Applications that determine the user’s location via a sensor must set this to true, defaults to false



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# File 'lib/googlestaticmap.rb', line 40

def sensor
  @sensor
end

#styles ⇒ Object

Styles - see developers.google.com/maps/documentation/maps-static/styling styles is should be represented as array of objects [‘featureArgument, element: ’elementArgument’, rule1: ‘rule1Arguement’, rule2: ‘rule2Arguement’, …, …]



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# File 'lib/googlestaticmap.rb', line 97

def styles
  @styles
end

#visible ⇒ Object

An optional array of MapLocation instances that should remain visible on the map, though no markers or other indicators will be displayed



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# File 'lib/googlestaticmap.rb', line 26

def visible
  @visible
end

#width ⇒ Object

Width of resulting image in pixels, defaults to 500, maximum 640



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# File 'lib/googlestaticmap.rb', line 17

def width
  @width
end

#zoom ⇒ Object

0 (the whole world) to 21 (individual buildings)



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# File 'lib/googlestaticmap.rb', line 36

def zoom
  @zoom
end

Instance Method Details

#get_map(output_file = nil, protocol = 'https') ⇒ Object

Connects to Google, retrieves the map, and returns the bytes for the image. Optionally, pass it an output name and the contents will get written to this file name output_file - optionally give the name of a file to write the output to.

Pass nil to not write the output to a file

protocol - specify http or https here for the protocol to retrieve the

map with. Defaults to http

return value - the binary data for the map



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# File 'lib/googlestaticmap.rb', line 176

def get_map(output_file=nil, protocol='https')
  protocol = 'https' unless protocol == 'http' || protocol == 'https'
  port = protocol == 'https' ? 443 : 80
  http = Net::HTTP.Proxy(@proxy_address,@proxy_port).new("maps.googleapis.com", port)
  http.use_ssl = protocol == 'https'

  resp = http.get2(relative_url(protocol))
  if resp && resp.is_a?(Net::HTTPSuccess)
    if output_file
      File.open(output_file, "wb") {|f| f << resp.body }
    end
    resp.body
  else
    if resp
      raise Exception.new("Error encountered while retrieving google map, code #{resp.code}, text #{resp.body}")
    else
      raise Exception.new("Error while retrieve google map, no response")
    end
  end
end

#get_styles ⇒ Object 



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# File 'lib/googlestaticmap.rb', line 197

def get_styles
  @styles.map do |style|
    values = style.each_pair.map do |(key, value)|
      "#{key.to_s}:#{value}"
    end
    ["style", values.join(CGI.escape('|'))]
  end
end

#relative_url(protocol = 'https') ⇒ Object

Returns the URL to retrieve the map, relative to maps.googleapis.com Example - “/maps/api/staticmap?params…”



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# File 'lib/googlestaticmap.rb', line 163

def relative_url(protocol='https')
  url(protocol).gsub(/[^\/]*\/\/maps\.googleapis\.com/, "")
end

#url(protocol = 'https') ⇒ Object

Returns the full URL to retrieve this static map. You can use this as the src for an img to display an image directly on a web page Example - “maps.googleapis.com/maps/api/staticmap?params…” protocol can be ‘http’, ‘https’ or :auto. Specifying :auto will not return

a protocol in the URL ("//maps.googleapis.com/..."), allowing the browser to
select the appropriate protocol (if the page is loaded with https, it will
use https). Defaults to https



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# File 'lib/googlestaticmap.rb', line 121

def url(protocol='https')
  unless @center || @markers.length > 0 || @paths.length > 0 || @visible.length > 0
    raise Exception.new("Need to specify either a center, markers, visible points, or a path")
  end
  if !@api_key.nil? && !@client_id.nil?
    raise Exception.new("You cannot specify both an API key and a client ID, only specify one")
  end
  if @api_key.nil? && @client_id.nil?
    raise Exception.new("You must specify either an API key, or a client ID/private key. Google requires this and the calls to Google will fail without one of these.")
  end
  if !@client_id.nil? && @private_key.nil?
    raise Exception.new("private_key must be specified if using a client ID")
  end
  protocol = 'https' unless protocol == 'http' || protocol == 'https' ||
                            protocol == :auto
  protocol = protocol == :auto ? '' : protocol + ":"
  base = "#{protocol}//maps.googleapis.com"
  path = "/maps/api/staticmap?"
  attrs = GoogleStaticMapHelpers.safe_instance_variables(self,
            ["markers", "visible", "paths", "width", "height", "center",
             "proxy_address", "proxy_port", "api_key", "client_id",
             "private_key", "styles", "plain_string"],
            :cgi_escape_values => true).to_a
  attrs << ["size", "#{@width}x#{@height}"] if @width && @height
  @markers.each {|m| attrs << ["markers",m.to_s] }
  @paths.each {|p| attrs << ["path",p.to_s] }
  attrs << ["visible", @visible.join(MAP_SEPARATOR)] if !@visible.nil? && @visible.any?
  attrs << ["center", @center.to_s] if !@center.nil?
  attrs << ["key", @api_key] if !@api_key.nil?
  attrs << ["client", @client_id] if !@client_id.nil?
  get_styles.each { |style| attrs << style } if !@styles.nil?
  path << attrs.sort_by {|k,v| k}.collect {|attr| "#{attr[0]}=#{attr[1]}"}.join("&")
  path << "&#{@plain_string}" if !@plain_string.nil?
  if (!@api_key.nil? || !@client_id.nil?) && !@private_key.nil?
    signature = GoogleStaticMapHelpers.sign(path, @private_key)
    path << "&signature=" << signature
  end
  base + path
end