Class: GeoCombine::OGP

Inherits:
Object
  • Object
show all
Includes:
Formatting
Defined in:
lib/geo_combine/ogp.rb

Overview

Data model for OpenGeoPortal metadata

Defined Under Namespace

Classes: InvalidMetadata

Constant Summary collapse

OGP_REQUIRED_FIELDS = 
%w[
  Access
  Institution
  LayerDisplayName
  LayerId
  MaxX
  MaxY
  MinX
  MinY
  Name
].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Formatting

#remove_lines, #sanitize, #sanitize_and_remove_lines, #sluggify

Constructor Details

#initialize(metadata) ⇒ OGP

Initializes an OGP object for parsing

Parameters:

  • metadata (String) —

    a valid serialized JSON string from OGP instance

Raises:



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# File 'lib/geo_combine/ogp.rb', line 17

def initialize(metadata)
  @metadata = JSON.parse(metadata)
  raise InvalidMetadata unless valid?
end

Instance Attribute Details

#metadata ⇒ Object (readonly)

Returns the value of attribute metadata.



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# File 'lib/geo_combine/ogp.rb', line 11

def metadata
  @metadata
end

Instance Method Details

#date ⇒ Object 



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# File 'lib/geo_combine/ogp.rb', line 81

def date
  DateTime.rfc3339(metadata['ContentDate'])
rescue StandardError
  nil
end

#envelope ⇒ String

Builds a Solr Envelope using CQL syntax

Returns:

  • (String)

Raises:

  • (ArgumentError) 


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# File 'lib/geo_combine/ogp.rb', line 125

def envelope
  raise ArgumentError unless west >= -180 && west <= 180 &&
                             east >= -180 && east <= 180 &&
                             north >= -90 && north <= 90 &&
                             south >= -90 && south <= 90 &&
                             west <= east && south <= north

  "ENVELOPE(#{west}, #{east}, #{north}, #{south})"
end

#fgdc ⇒ Object 



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# File 'lib/geo_combine/ogp.rb', line 143

def fgdc
  GeoCombine::Fgdc.new(metadata['FgdcText']) if metadata['FgdcText']
end

#geoblacklight_terms ⇒ Hash

Builds a Geoblacklight Schema type hash from Esri Open Data portal metadata

Returns:

  • (Hash) 


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# File 'lib/geo_combine/ogp.rb', line 51

def geoblacklight_terms
  {
    # Required fields
    dc_identifier_s: identifier,
    layer_slug_s: slug,
    dc_title_s: metadata['LayerDisplayName'],
    solr_geom: envelope,
    dct_provenance_s: institution,
    dc_rights_s: metadata['Access'],
    geoblacklight_version: '1.0',

    # Recommended fields
    dc_description_s: metadata['Abstract'],
    layer_geom_type_s: ogp_geom,
    dct_references_s: references,
    layer_id_s: "#{metadata['WorkspaceName']}:#{metadata['Name']}",

    # Optional
    dct_temporal_sm: [metadata['ContentDate']],
    dc_format_s: ogp_formats,
    # dct_issued_dt
    # dc_language_s
    dct_spatial_sm: placenames,
    solr_year_i: year,
    dc_publisher_s: metadata['Publisher'],
    dc_subject_sm: subjects,
    dc_type_s: 'Dataset'
  }.compact
end

#ogp_formats ⇒ Object

OGP doesn’t ship format types, so we just try and be clever here.



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# File 'lib/geo_combine/ogp.rb', line 104

def ogp_formats
  case metadata['DataType']
  when 'Paper Map', 'Raster'
    'GeoTIFF'
  when 'Polygon', 'Point', 'Line'
    'Shapefile'
  else
    raise ArgumentError, metadata['DataType']
  end
end

#ogp_geom ⇒ Object

Convert “Paper Map” to Raster, assumes all OGP “Paper Maps” have WMS



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# File 'lib/geo_combine/ogp.rb', line 93

def ogp_geom
  case metadata['DataType']
  when 'Paper Map'
    'Raster'
  else
    metadata['DataType']
  end
end

#placenames ⇒ Object 



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# File 'lib/geo_combine/ogp.rb', line 139

def placenames
  fgdc.metadata.xpath('//placekey').map(&:text) if fgdc
end

#references ⇒ String

Converts references to json

Returns:

  • (String) 


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# File 'lib/geo_combine/ogp.rb', line 118

def references
  references_hash.to_json
end

#subjects ⇒ Object 



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# File 'lib/geo_combine/ogp.rb', line 135

def subjects
  fgdc.metadata.xpath('//themekey').map(&:text) if fgdc
end

#to_geoblacklight ⇒ GeoCombine::Geoblacklight

Creates and returns a Geoblacklight schema object from this metadata

Returns:



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# File 'lib/geo_combine/ogp.rb', line 43

def to_geoblacklight
  GeoCombine::Geoblacklight.new(geoblacklight_terms.to_json)
end

#valid? ⇒ Boolean

Runs validity checks on OGP metadata to ensure fields are present

Returns:

  • (Boolean) 


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# File 'lib/geo_combine/ogp.rb', line 36

def valid?
  OGP_REQUIRED_FIELDS.all? { |k| metadata[k].present? }
end

#year ⇒ Object 



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# File 'lib/geo_combine/ogp.rb', line 87

def year
  date&.year
end