cartodb/services/wms/proxy.rb

103 lines
2.7 KiB
Ruby
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2020-06-15 10:58:47 +08:00
require 'uri'
require 'nokogiri'
require_relative '../../lib/carto/http/client'
module CartoDB
module WMS
class Proxy
SERVER_XPATH = "//OnlineResource[1]"
FORMATS_XPATH = "//GetMap/Format"
LAYERS_XPATH = "//Layer/Layer[BoundingBox or LatLonBoundingBox]"
def initialize(url, preloaded_xml=nil)
@url = url
@response = preloaded_xml
end
def serialize
run
{ server: server, formats: formats, layers: layers }
end
def run
request_capabilities unless response
self
end
def request_capabilities
http_client = Carto::Http::Client.get('wmsproxy')
response = http_client.get(url, followlocation: true)
raise URI::InvalidURIError unless [200, 201].include?(response.code)
@response = response.response_body
nil
end
def document
Nokogiri::XML::Document.parse(response).remove_namespaces!
end
def server
(document.at_xpath(SERVER_XPATH) || {})['href']
end
def formats
document.xpath(FORMATS_XPATH).map(&:text)
end
def layers
document.xpath(LAYERS_XPATH).map { |element|
name = element.xpath("./Name").first
title = element.xpath("./Title").first
{
name: (name.text if name),
title: (title.text if title),
crs: crs_for_element(element),
srs: srs_for_element(element),
bounding_boxes: bounding_boxes_for(element),
attribution: nil
}
}
end
def crs_for_element(element)
crs = element.xpath("./CRS").map { |element|
element.text
}.compact
end
def srs_for_element(element)
srs = element.xpath("./SRS").map { |element|
element.text
}.compact
end
def bounding_boxes_for(element)
bounding_boxes = element.xpath("./BoundingBox").map { |element|
srs = element.xpath("./@SRS").first
crs = element.xpath("./@CRS").first
minx = element.xpath("./@minx").first
miny = element.xpath("./@miny").first
maxx = element.xpath("./@maxx").first
maxy = element.xpath("./@maxy").first
{
srs: (srs.value if srs),
crs: (crs.value if crs),
minx: (minx.value if minx),
miny: (miny.value if miny),
maxx: (maxx.value if maxx),
maxy: (maxy.value if maxy),
}
}
end
attr_reader :response
private
attr_reader :url
end # Proxy
end # WMS
end # CartoDB