Module: QDA::Backend::SQLite::Upgradeable

Defined in:
lib/weft/backend/sqlite/upgradeable.rb

Overview

This module provides support for opening projects created in older versions of Weft.

Instance Method Summary collapse

Instance Method Details

#do_version_format_upgrading ⇒ Object

This is called when a project is opened. It checks whether any changes need to be made to the storage format.



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# File 'lib/weft/backend/sqlite/upgradeable.rb', line 10

def do_version_format_upgrading()
  version = get_preference('LastModifiedVersion') || 
    get_preference('CreateVersion')

  # don't do anything to those created in testing versions, just
  # mark as last-opened in this version.
  if version == QDA::Version.default_version()
    save_preference('LastModifiedVersion', WEFT_VERSION)
  end

  # 0.9.4 and earlier - add indexes to tables
  if version.nil?
    @dbh.execute_batch(QDA::Backend::SQLite::Schema::SCHEMA_INDEXES)
  end

  # 0.9.5 and earlier - upgrade the category tree storage format
  if version.nil? || version == '0.9.5'
    legacy_category_tree_storage()
    save_preference('LastModifiedVersion', WEFT_VERSION)
  end
  
  begin
    old_codes = get_root_category('CODES')
    old_codes.name = 'CATEGORIES'
    save_category(old_codes)
  rescue QDA::NotFoundError
  end
end

#legacy_category_tree_storage ⇒ Object

This is a change from 0.9.5 -> 0.9.6; Category tree structure used to be stored in XML in the database, is now stored as a marshalled CategoryTree pure ruby object.



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# File 'lib/weft/backend/sqlite/upgradeable.rb', line 42

def legacy_category_tree_storage()
  @cat_tree = CategoryTree.new()

  build_cat = Proc.new do | elem, parent |
    cat =  @cat_tree.add( parent,
                          elem.attributes['dbid'].to_i,
                          elem.attributes['name'] )
    elem.each_child { | kid | build_cat.call(kid, cat.dbid) }
  end

  xml  = @dbh.get_first_value("SELECT xml FROM category_structure")
  doc = REXML::Document.new(xml)
  doc.root.each_child { | elem | build_cat.call(elem, nil) }

  @dbh.transaction do
    xml = @cat_tree.serialise
    @dbh.execute("UPDATE category_structure SET xml = ? ", xml )
  end
end