class PermanentRecord

Returns collection of all PermanentRecord instances.

Example:

>> Model.all
=> [@model1, @model2, ...]

# File lib/permanent_record.rb, line 43
def all
  data.map{|d| self.new(d)}
end

Find instance given id. Returns instance if found; nil otherwise.

Example:

>> Model.find(42)
=> @model

# File lib/permanent_record.rb, line 54
def find id
  self.find_by_attribute(:id, id)
end

Find instance given attribute name and expected value. Returns instance if found; nil otherwise.

Example:

>> Model.find_by_attribute(:bacon, 'chunky')
=> @model

# File lib/permanent_record.rb, line 65
def find_by_attribute key, value
  found = data.find{|d| d[key.to_sym].to_s == value.to_s}
  self.new(found) if found
end

Oh, just for fun let’s metaprogram some method missing! Provides ‘find_by_<attr>’ finders if you don’t like ‘where’. Returns instance if found; nil otherwise.

Example:

>> Model.find_by_bacon('chunky')
=> @model

# File lib/permanent_record.rb, line 91
def method_missing(method, *arguments, &block)
  match = method.to_s.match(/^find_by_(.*)$/)
  if match && valid_attribute?($1.to_sym)
    find_by_attribute($1.to_sym, arguments.first)
  else
    super
  end
end

Constructs a new PermanentRecord instance. Set instance variable and reader based on input hash.

# File lib/permanent_record.rb, line 14
def initialize attrs={}
  attrs.each do |key, value|
    if valid_attribute? key
      self.instance_variable_set("@#{key}", value) 
      self.class.class_eval{attr_reader key}
    end
  end
end

Find instance(s) given hash of attribute key/values. Returns all instances if found; empty array otherwise.

Example:

>> Model.where(bacon: 'chunky', cats: 'calico')
=> [@model1, @model2, ...]

# File lib/permanent_record.rb, line 77
def where *attrs
  keys = attrs.first.keys
  found = data.map{|d| d if d.reject{|key,_| !keys.include?(key)} == attrs.first}
  found.compact.map{|f| self.new(f)}
end

Retrieve or load model attributes.

# File lib/permanent_record.rb, line 167
def attributes
  @_attributes ||= attributes_from_data
end

Find attributes based on first data item keys This might be something worth explicitly stating in an ‘attributes’ config or something… but for now I’m going with the lazy way out, and we’ll just check the first data item. So please be sure to have well formed data!

# File lib/permanent_record.rb, line 177
def attributes_from_data
  data.first.keys
end

Retrieve or load raw data.

# File lib/permanent_record.rb, line 141
def data
  @_data ||= data_from_constant
end

Auto load data from constant; pluralized model name ie: If your model is called ZooKeeper, this will try and

auto load a constant called ZOO_KEEPERS. You can put that
constant anywhere you want ... like in the model, or in
a constants.rb file, or maybe a zoo_keeprs.rb file.

# File lib/permanent_record.rb, line 151
def data_from_constant
  data = eval(self.name.to_s.underscore.pluralize.upcase)
  format_data data
end

Add sequential id to all records. This can be overwritten if an id is specified in the data. CAUTION! If defining your own ids please make sure they’re unique!

# File lib/permanent_record.rb, line 160
def format_data data
  data = data.each_with_index.map{|d, i| {id: i+1}.merge(d)}
  data.each(&:symbolize_keys!)
end

Declares source for PermanentRecord class data. PermanentRecord pretty much just wants to source any ol’ array of hashes. If not declared, it’ll default to a pluralized model name constant. ie: If your model is called MyModel, this’ll try and find MY_MODELS.

The default example, with NO source defined:

class MyModel < PermanentRecord
end

Example with source constant explicitly defined:

class MyModel < PermanentRecord
  source SOME_CONSTANT
end

Another example with a source YAML file explicitly defined:

class MyModel < PermanentRecord
  source YAML.load(File.read('path/to/yaml/file.yml'))
end

I doubt you’d want to define your source as an explicit array of hash, but just to drive home this “any array of hashes” idea here’s an example:

class MyModel < PermanentRecord
  source [{eyes: 'blue', hair: 'blonde'}, {eyes: 'brown', hair: 'green'}]
end

# File lib/permanent_record.rb, line 135
def source data=nil
  @_data = format_data data
end

Check if attribute name is valid.

# File lib/permanent_record.rb, line 183
def valid_attribute? key
  attributes.include?(key)
end

Overrides equality to match ids.

# File lib/permanent_record.rb, line 32
def == record
  self.id == record.try(:id)
end

For working with Rails routing helpers. Override in your PermanentRecord class to adjust URLs.

# File lib/permanent_record.rb, line 26
def to_param
  self.id
end

Check if attribute name is valid.

# File lib/permanent_record.rb, line 105
def valid_attribute? key
  self.class.valid_attribute?(key)
end