Module: DataMapper::Persevere::Migrations

Defined in:
lib/persevere_adapter/migrations.rb

Instance Method Summary collapse

Instance Method Details

#create_model_storage(model) ⇒ Object

Creates the persevere schema from the model.

Parameters:

  • model (DataMapper::Model) —

    The model that corresponds to the storage schema that needs to be created.



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# File 'lib/persevere_adapter/migrations.rb', line 27

def create_model_storage(model)
  model = Persevere.enhance(model)
  name       = self.name
  properties = model.properties_with_subclasses(name)
  
  return false if storage_exists?(model.storage_name(name))
  return false if properties.empty?

  # Make sure storage for referenced objects exists
  model.relationships.each_pair do |n, r|
    if ! storage_exists?(r.child_model.storage_name)
      put_schema({'id' => r.child_model.storage_name, 'properties' => {}})
    end
  end
  schema_hash = model.to_json_schema_hash()
  
  return true unless put_schema(schema_hash) == false
  false
end

#destroy_model_storage(model) ⇒ Object

Destroys the persevere schema from the model.

Parameters:

  • model (DataMapper::Model) —

    The model that corresponds to the storage schema that needs to be destroyed.



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# File 'lib/persevere_adapter/migrations.rb', line 89

def destroy_model_storage(model)
  model = Persevere.enhance(model)
  return true unless storage_exists?(model.storage_name(name))
  schema_hash = model.to_json_schema_hash()
  return true unless delete_schema(schema_hash) == false
  false
end

#storage_exists?(storage_name) ⇒ Boolean

Returns whether the storage_name exists.

Parameters:

  • storage_name (String) —

    a String defining the name of a storage, for example a table name.

Returns:

  • (Boolean) —

    true if the storage exists



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# File 'lib/persevere_adapter/migrations.rb', line 14

def storage_exists?(storage_name)
  class_names = JSON.parse(@persevere.retrieve('/Class/[=id]').body)
  return true if class_names.include?("Class/"+storage_name)
  false
end

#upgrade_model_storage(model) ⇒ Object

Updates the persevere schema from the model.

Parameters:

  • model (DataMapper::Model) —

    The model that corresponds to the storage schema that needs to be updated.



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# File 'lib/persevere_adapter/migrations.rb', line 54

def upgrade_model_storage(model)
  model = Persevere.enhance(model)
  name       = self.name
  properties = model.properties_with_subclasses(name)
  
  DataMapper.logger.debug("Upgrading #{model.name}")
  
  if success = create_model_storage(model)
    return properties
  end
  
  new_schema_hash = model.to_json_schema_hash()
  current_schema_hash = get_schema(new_schema_hash['id'])[0]
  # TODO: Diff of what is there and what will be added.

  new_properties = properties.map do |property|
    prop_name = property.name.to_s
    prop_type = property.type
    next if prop_name == 'id' || 
            (current_schema_hash['properties'].has_key?(prop_name) && 
            new_schema_hash['properties'][prop_name]['type'] == current_schema_hash['properties'][prop_name]['type'] )
    property
  end.compact
  
  return new_properties unless update_schema(new_schema_hash) == false
  return nil
end