Class: Pod4::NullInterface

Inherits:
Interface show all
Defined in:
lib/pod4/null_interface.rb

Overview

Pod4 Interface *for testing*. Fakes a table and records.

Example:

class TestModel < Pod4::Model
  attr_columns :one, :two
  set_interface NullInterface.new( :one, :two [ {one: 1, two: 2},
                                                {one: 2, two: 4} ] )
  ...

The first column passed is taken to be the ID. We default to autoincrement = true, as standard. Note that ID values for the initial data are not auto-assigned; you need to specify them.

You can switch to autoincrement = false by setting ‘interface.id_ai = false`.

Note: this is quite different from the behaviour before v1.0, where NullInterface effectively only allowed you to create a non-autoincrement interface.

Constant Summary

Constants inherited from Interface

Interface::ACTIONS

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Interface

#_connection, #close_connection, #new_connection

Methods included from Metaxing

#define_class_method, #metaclass

Constructor Details

#initialize(*cols, data) ⇒ NullInterface

Initialise the interface by passing it a list of columns and an array of hashes to fill them.



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# File 'lib/pod4/null_interface.rb', line 36

def initialize(*cols, data)
  raise ArgumentError, "no columns"  if cols.nil? || cols == []

  @cols   = cols.dup.map(&:to_sym)
  @data   = Array.new(data.dup).flatten 
  @id_fld = @cols.first
  @id_ai  = true

rescue => e
  handle_error(e)
end

Instance Attribute Details

#id_ai ⇒ Object

Returns the value of attribute id_ai.



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# File 'lib/pod4/null_interface.rb', line 31

def id_ai
  @id_ai
end

#id_fld ⇒ Object (readonly)

Returns the value of attribute id_fld.



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# File 'lib/pod4/null_interface.rb', line 30

def id_fld
  @id_fld
end

Instance Method Details

#create(record) ⇒ Object

Record is a hash of field: value

Note that we will store any old crap, not just the fields you named in new().



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# File 'lib/pod4/null_interface.rb', line 70

def create(record)
  raise(ArgumentError, "Create requires an ID") if record.nil? || ! record.respond_to?(:to_h)

  raise(ArgumentError, "Record missing ID field") \
    if !@id_ai && record[@id_fld].nil? && record[@id_fld.to_s].nil?

  datum = record.to_h
  datum[@id_fld] = (@data.size + 1) if @id_ai
  @data << record.to_h

  datum[@id_fld]

rescue => e
  handle_error(e)
end

#delete(id) ⇒ Object

ID is that first column



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# File 'lib/pod4/null_interface.rb', line 118

def delete(id)
  raise(ArgumentError, "Delete requires an ID")  if id.nil?
  raise(Pod4::CantContinue, "'No record found with ID '#{id}'") if read(id).empty?

  @data.delete_if {|r| r[@id_fld] == id }
  self
rescue => e
  handle_error(e)
end

#list(selection = nil) ⇒ Object

Selection is a hash, but only the first key/value pair is honoured.



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# File 'lib/pod4/null_interface.rb', line 51

def list(selection=nil)
  if selection
    key, value = selection.to_a.first
    rows = @data.find_all {|r| r[key.to_sym] == value}
  else
    rows = @data
  end

  rows.map{|x| Octothorpe.new(x) }

rescue => e
  handle_error(e)
end

#read(id) ⇒ Object

ID is the first column you named in new()



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# File 'lib/pod4/null_interface.rb', line 89

def read(id)
  raise(ArgumentError, "Read requires an ID") if id.nil?

  rec = @data.find{|x| x[@id_fld] == id }
  Octothorpe.new(rec)

rescue => e
  handle_error(e)
end

#update(id, record) ⇒ Object

ID is the first column you named in new(). Record should be a Hash or Octothorpe. Again, note that we don’t care what columns you send us.



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# File 'lib/pod4/null_interface.rb', line 103

def update(id, record)
  raise(ArgumentError, "Update requires an ID") if id.nil?

  rec = @data.find{|x| x[@id_fld] == id }
  raise Pod4::CantContinue, "No record found with ID '#{id}'" unless rec

  rec.merge!(record.to_h)
  self
rescue => e
  handle_error(e)
end