Class: WAB::Impl::Model

Inherits:
Object
  • Object
show all
Defined in:
lib/wab/impl/model.rb

Overview

The Model class is used to store data when using the WAB::Impl::Shell. It is not intended for any other use. The get and query methods are the primary means of interacting with the model.

The Model is simple in that it stores data in a Hash references by ref numbers. Data is stores in a directory as separate JSON files that are named as the ref number as a 16 character hexidecimal.

Instance Method Summary collapse

Constructor Details

#initialize(dir, indent = 0) ⇒ Model

Create a new Model using the designated directory as the store.

dir

directory to store data in



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# File 'lib/wab/impl/model.rb', line 20

def initialize(dir, indent=0)
  @dir = dir.nil? ? nil : File.expand_path(dir)
  @cnt = 0
  @indent = indent
  @map = {}
  @lock = Thread::Mutex.new
  FileUtils.mkdir_p(@dir) unless @dir.nil? || Dir.exist?(@dir)
  load_files unless @dir.nil?
end

Instance Method Details

#get(ref) ⇒ Object

Get a single record in the database. A WAB::Impl::Data object is returned if not nil.

ref

references number of the object to retrieve.



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# File 'lib/wab/impl/model.rb', line 34

def get(ref)
  @map[ref]
end

#query(tql) ⇒ Object

Execute a TQL query.

_Note that the current implementation does not support nested data retrieval.

tql

query to execute



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# File 'lib/wab/impl/model.rb', line 44

def query(tql)
  rid = tql[:rid]
  where = nil
  filter = nil
  if tql.has_key?(:where)
    w = tql[:where]
    where = w.is_a?(Array) ? ExprParser.parse(w) : w
  end
  filter = ExprParser.parse(tql[:filter]) if tql.has_key?(:filter)

  if tql.has_key?(:insert)
    insert(tql[:insert], rid, where, filter)
  elsif tql.has_key?(:update)
    update(tql[:update], rid, where, filter)
  elsif tql.has_key?(:delete)
    delete(tql[:delete], rid, where, filter)
  else
    select(tql[:select], rid, where, filter)
  end
end