Class: Yequel::Model

Inherits:
Object
  • Object
show all
Defined in:
lib/yequel.rb

Defined Under Namespace

Classes: Array, Hash

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name) ⇒ Model

Initialize the model object. Provides a wrapper around the dataset Each table is created as unique class, and an instance is created

Example:

class Artists < Yequel::Model
end
Artist=Artists.new



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# File 'lib/yequel.rb', line 23

def initialize(name)
  @name = name
  load       
end

Instance Attribute Details

#name ⇒ Object

, :rkeys



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# File 'lib/yequel.rb', line 11

def name
  @name
end

#rarray ⇒ Object

, :rkeys



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# File 'lib/yequel.rb', line 11

def rarray
  @rarray
end

Instance Method Details

#[](key) ⇒ Object

is query command that shows a record base on the :id key

Examples:

Artist[1]



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# File 'lib/yequel.rb', line 171

def[](key)
  #k = @rkeys.index(key)
  #@rarray[k]
  p key
  #p self.rarray
  self.rarray.get(key).merge!({:mod_name=>self.name})
end

#all ⇒ Object

All is query command that shows all records in the dataset

Examples:

Artist.all



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# File 'lib/yequel.rb', line 155

def all
  @rarray
end

#count ⇒ Object

Count is query command that counts the records in the dataset

Examples:

Artist.count



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# File 'lib/yequel.rb', line 163

def count
  @rarray.length
end

#delete(key) ⇒ Object

Delete is an action command that deletes a single record An argument error is thrown if the record key does not exist

Examples:

Artist.delete(4)



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# File 'lib/yequel.rb', line 119

def delete(key)
  result = @rarray.get(key)
  if result
    @rarray.delete(result)
    store
  else
    raise ArgumentError,'Cannot delete - no matching id', caller  
  end
end

#first(options = {}) ⇒ Object

First is query command that shows the first record in the dataset

Examples:

Artist.first
Artist.first(:name=>'AS')



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# File 'lib/yequel.rb', line 135

def first(options ={})
  if options.length > 0
    @rarray.where(options).first.merge!({:mod_name=>self.name})
  else
    @rarray.first.merge!({:mod_name=>self.name})
  end
end

#insert(args) ⇒ Object

Insert is an action command and adds new records to the dataset All data is stored in string format An argument error is thrown if the record key is already used

Examples:

Artist.insert(:id=>1, :name=>"YJ")



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# File 'lib/yequel.rb', line 82

def insert (args)
  #p @name
  #p '.......'
  p args
  p self.rarray
  if self.rarray.get(args[:id]).nil?
    model={:mod_name=>@name}
    p self
    #self.rarray << args.merge(model)
    self.rarray << args  
    self.store
  else
    raise ArgumentError, 'Cannot insert - id already exists', caller
  end
end

#last ⇒ Object

Last is query command that shows the last record in the dataset

Examples:

Artist.last



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# File 'lib/yequel.rb', line 147

def last
  @rarray.reverse.first    
end

#load ⇒ Object

Loads the dataset with the name provided from initialization Method is also used to refresh data after a dataset action YAML::Store data will be loaded into a hash image (:dshash) that is accessible using the :id number as a key Hash will be converted to a Array of hashed records to support querying of the dataset

Example:

load



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# File 'lib/yequel.rb', line 37

def load
  #p 'loading ...'
  #p @name
  @rarray = Array.new
  begin
    dshash = YAML.load_file('db/'+@name+'.store') 
    #p dshash
    #@rkeys = Array.new
    #p 'loading ...'
    dshash.each {|k,v|           # converts strings into symbols
      cid = dshash[k]["id"]
      next if cid < 1            # do not transform if id < 1 
      #@rkeys << k
      rhash = Hash.new     
      v.each {|k2,v2|
      #p k2
      #p v2
        rhash[k2.to_sym] = v2
      }
      @rarray << rhash
    }
  rescue
    p 'no file now'  
    self.insert({:id=>0})
  end
end

#order(key) ⇒ Object

Order is a query command that orders an array based on a key This command is chainable



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# File 'lib/yequel.rb', line 181

def order(key)
  #newarray=Array.new
  #@dataset.values.each { |item| newarray << item.varray}
  #newarray.order(key)  
  @rarray.order(key)
end

#store ⇒ Object 



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# File 'lib/yequel.rb', line 64

def store
  dshash = Hash.new
  @rarray.each { |item|
    outhash = Hash.new
    item.each { |k,v| outhash[k.to_s] = v}
    dshash[item[:id]]=outhash
  }
  File.open('db/'+@name+'.store', 'w') do |out|   # To file
    YAML.dump(dshash, out)
  end    
end

#update(args) ⇒ Object

Update is an action command and updates existing records An argument error is thrown if the record key does not exist

Examples:

Artist.update(:id=>1, :name=>"YJM")



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# File 'lib/yequel.rb', line 103

def update (args)
  p 'updating ...'
  if self.rarray.get(args[:id])    
    key = args[:id] - 1
    @rarray[key].merge!(args)
  else
    raise ArgumentError, 'Cannot update - id not found', caller
  end
  self.store
end

#where(*args) ⇒ Object

Where is a query command that filters the array This command is chainable



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# File 'lib/yequel.rb', line 190

def where(*args)
  @rarray.where(*args)
end