Class: OGR::Driver

Inherits:
Object
  • Object
show all
Includes:
GDAL::Logger, GDAL::MajorObject, OGR::DriverMixins::CapabilityMethods
Defined in:
lib/ogr/driver.rb

Overview

Wrapper for OGR’s Driver class. In this case, to use a driver, find the driver you’re looking for using .by_name or .by_index; that will return an instance of an OGR::Driver.

More about the C API here: www.gdal.org/ogr_drivertut.html.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from OGR::DriverMixins::CapabilityMethods

#can_create_data_source?, #can_delete_data_source?

Methods included from GDAL::MajorObject

#all_metadata, #description, #metadata, #metadata_domain_list, #metadata_item, #null?, #set_metadata_item

Constructor Details

#initialize(driver) ⇒ Driver

You probably don’t want to use this directly–see .by_name and .at_index to instantiate a OGR::Driver object.

Parameters:



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# File 'lib/ogr/driver.rb', line 57

def initialize(driver)
  @c_pointer = GDAL._pointer(OGR::Driver, driver)
end

Instance Attribute Details

#c_pointer ⇒ FFI::Pointer (readonly)

Returns C pointer that represents the Driver.

Returns:

  • (FFI::Pointer) —

    C pointer that represents the Driver.



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# File 'lib/ogr/driver.rb', line 51

def c_pointer
  @c_pointer
end

Class Method Details

.at_index(index) ⇒ OGR::Driver

Parameters:

  • index (Integer) —

    Index of the registered driver. Must be less than OGR::Driver.count.

Returns:

Raises:



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# File 'lib/ogr/driver.rb', line 36

def self.at_index(index)
  raise OGR::DriverNotFound, index if index > count

  driver_ptr = FFI::OGR::API.OGRGetDriver(index)
  raise OGR::DriverNotFound, index if driver_ptr.null?

  new(driver_ptr)
end

.by_name(name) ⇒ OGR::Driver

Parameters:

  • name (String) —

    Short name of the registered OGRDriver.

Returns:

Raises:



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# File 'lib/ogr/driver.rb', line 25

def self.by_name(name)
  driver_ptr = FFI::OGR::API.OGRGetDriverByName(name)
  raise OGR::DriverNotFound, name if driver_ptr.null?

  new(driver_ptr)
end

.count ⇒ Integer

Returns:



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# File 'lib/ogr/driver.rb', line 18

def self.count
  FFI::OGR::API.OGRGetDriverCount
end

.names ⇒ Array<String>

Returns:



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# File 'lib/ogr/driver.rb', line 46

def self.names
  Array.new(count) { |i| at_index(i).name }.sort
end

Instance Method Details

#copy_data_source(source_data_source, new_file_name, **options) ⇒ OGR::DataSource?

Parameters:

Returns:

Raises:



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# File 'lib/ogr/driver.rb', line 122

def copy_data_source(source_data_source, new_file_name, **options)
  source_ptr = GDAL._pointer(OGR::DataSource, source_data_source)

  raise OGR::InvalidDataSource, source_data_source if source_ptr.nil? || source_ptr.null?

  options_ptr = GDAL::Options.pointer(options)

  data_source_ptr =
    FFI::OGR::API.OGR_Dr_CopyDataSource(@c_pointer, source_ptr, new_file_name, options_ptr)

  raise OGR::InvalidDataSource, "Unable to copy data source to #{new_file_name}" if data_source_ptr.null?

  OGR::DataSource.new(data_source_ptr, nil)
end

#create_data_source(file_name, **options) {|ds| ... } ⇒ OGR::DataSource?

Creates a new data source at path file_name. Yields the newly created data source to a block, if given. NOTE: in order to write out all in-memory data, you need to call #close on the created DataSource.

Parameters:

  • file_name (String)
  • options (Hash)

Yields:

  • (ds)

Returns:

Raises:



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# File 'lib/ogr/driver.rb', line 89

def create_data_source(file_name, **options)
  unless test_capability("CreateDataSource")
    raise OGR::UnsupportedOperation, "This driver does not support data source creation."
  end

  options_ptr = GDAL::Options.pointer(options)

  data_source_ptr = FFI::OGR::API.OGR_Dr_CreateDataSource(@c_pointer,
                                                          file_name, options_ptr)
  raise OGR::CreateFailure, "Unable to create DataSource '#{file_name}'" if data_source_ptr.null?

  ds = OGR::DataSource.new(data_source_ptr, "w")
  yield ds if block_given?

  ds
end

#delete_data_source(file_name) ⇒ Object

Parameters:

Raises:



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# File 'lib/ogr/driver.rb', line 108

def delete_data_source(file_name)
  unless test_capability("DeleteDataSource")
    raise OGR::UnsupportedOperation, "This driver does not support deleting data sources."
  end

  OGR::ErrorHandling.handle_ogr_err("Unable to delete data source '#{file_name}'") do
    FFI::OGR::API.OGR_Dr_DeleteDataSource(@c_pointer, file_name)
  end
end

#name ⇒ String

Returns:



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# File 'lib/ogr/driver.rb', line 62

def name
  name, ptr = FFI::OGR::API.OGR_Dr_GetName(@c_pointer)
  ptr.autorelease = false

  name
end

#open(file_name, access_flag = "r") ⇒ OGR::DataSource?

Parameters:

  • file_name (String)
  • access_flag (String) (defaults to: "r") —

    ‘r’ or ‘w’.

Returns:

Raises:



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# File 'lib/ogr/driver.rb', line 72

def open(file_name, access_flag = "r")
  update = OGR._boolean_access_flag(access_flag)

  data_source_ptr = FFI::OGR::API.OGR_Dr_Open(@c_pointer, file_name, update)

  raise OGR::InvalidDataSource, "Unable to open data source at #{file_name}" if data_source_ptr.null?

  OGR::DataSource.new(data_source_ptr, nil)
end

#test_capability(capability) ⇒ Boolean

Parameters:

Returns:

  • (Boolean) 


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# File 'lib/ogr/driver.rb', line 139

def test_capability(capability)
  FFI::OGR::API.OGR_Dr_TestCapability(@c_pointer, capability)
end