Class: Dwca::Packer::Data

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

Overview

Wrapper to build DWCA zipfiles for a specific project. See tasks/accesssions/report/dwc_controller.rb for use.

With help from thinkingeek.com/2013/11/15/create-temporary-zip-file-send-response-rails/

Usage:

begin
 data = Dwca::Packer::Data.new(DwcOccurrence.where(project_id: sessions_current_project_id)
ensure
 data.cleanup
end

Always use the ensure/data.cleanup pattern!

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(record_scope) ⇒ Data

Returns a new instance of Data.

Parameters:

  • args (Hash)

Raises:

  • (ArgumentError) 


24
25
26
27
28
 
# File 'lib/dwca/packer.rb', line 24

def initialize(record_scope)
  raise ArgumentError, 'must pass a scope' if !record_scope.kind_of?( ActiveRecord::Relation )
  @scope = record_scope
  @total = scope.count('*')
end

Instance Attribute Details

#data ⇒ Tempfile

Returns the csv data as a tempfile.

Returns:

  • (Tempfile) —

    the csv data as a tempfile



61
62
63
 
# File 'lib/dwca/packer.rb', line 61

def data
  @data
end

#eml ⇒ Tempfile

This is a stub, and only half-heartedly done. You should be using IPT for the time being. See also

https://github.com/gbif/ipt/wiki/resourceMetadata
https://github.com/gbif/ipt/wiki/resourceMetadata#exemplar-datasets

Returns:

  • (Tempfile) —

    metadata about this dataset



82
83
84
 
# File 'lib/dwca/packer.rb', line 82

def eml
  @eml
end

#filename ⇒ String (readonly)

the name of zipfile

Returns:

  • (String) 


200
201
202
 
# File 'lib/dwca/packer.rb', line 200

def filename
  @filename
end

#meta ⇒ Tempfile

Returns the actual data file.

Returns:

  • (Tempfile) —

    the actual data file



153
154
155
 
# File 'lib/dwca/packer.rb', line 153

def meta
  @meta
end

#scope ⇒ Object

Returns the value of attribute scope.



20
21
22
 
# File 'lib/dwca/packer.rb', line 20

def scope
  @scope
end

#total ⇒ Object

Returns the value of attribute total.



20
21
22
 
# File 'lib/dwca/packer.rb', line 20

def total
  @total
end

#zipfile ⇒ Tempfile

Returns the zipfile.

Returns:

  • (Tempfile) —

    the zipfile



193
194
195
 
# File 'lib/dwca/packer.rb', line 193

def zipfile
  @zipfile
end

Instance Method Details

#cleanup ⇒ True

Returns close and delete all temporary files.

Returns:

  • (True) —

    close and delete all temporary files



207
208
209
210
211
212
213
214
215
216
217
 
# File 'lib/dwca/packer.rb', line 207

def cleanup
  zipfile.close
  zipfile.unlink
  meta.close
  meta.unlink
  eml.close
  eml.unlink
  data.close
  data.unlink
  true
end

#csv ⇒ CSV

Returns the data as a CSV object.

Returns:

  • (CSV) —

    the data as a CSV object



32
33
34
35
36
37
38
39
 
# File 'lib/dwca/packer.rb', line 32

def csv
  Export::Download.generate_csv(
    scope.computed_columns,
    trim_columns: true,
    trim_rows: true,
    header_converters: [:dwc_headers]
  )
end

#csv_headers ⇒ Array

Returns use the temporarily written, and refined, CSV file to read of the existing headers.

Returns:

  • (Array) —

    use the temporarily written, and refined, CSV file to read of the existing headers



43
44
45
46
47
48
49
50
51
 
# File 'lib/dwca/packer.rb', line 43

def csv_headers
  return [] if no_records?
  d = CSV.open(data, headers: true, col_sep: "\t")
  d.read
  h = d.headers
  d.rewind
  h.shift # get rid of id, it's special in meta
  h
end

#getzip ⇒ File

Returns the stream to use in send_data, for example.

Returns:

  • (File) —

    the stream to use in send_data, for example



179
180
181
182
183
184
185
186
187
188
189
 
# File 'lib/dwca/packer.rb', line 179

def getzip
  Zip::OutputStream.open(zipfile) { |zos| }

  Zip::File.open(zipfile.path, Zip::File::CREATE) do |zip|
    zip.add('data.csv', data.path)
    zip.add('meta.xml', meta.path)
    zip.add('eml.xml', eml.path)
  end

  File.read(zipfile.path)
end

#no_records? ⇒ Boolean

Returns true if provided scope returns no records.

Returns:

  • (Boolean) —

    true if provided scope returns no records



55
56
57
 
# File 'lib/dwca/packer.rb', line 55

def no_records?
  total == 0
end