Module: Sequel::Model::InstanceMethods

Defined in:
lib/sequel/lib/sequel/model/base.rb

Overview

Sequel::Model instance methods that implement basic model functionality.

  • All of the methods in HOOKS create instance methods that are called by Sequel when the appropriate action occurs. For example, when destroying a model object, Sequel will call before_destroy, do the destroy, and then call after_destroy.

  • The following instance_methods all call the class method of the same name: columns, dataset, db, primary_key, db_schema.

  • The following instance methods allow boolean flags to be set on a per-object basis: raise_on_save_failure, raise_on_typecast_failure, strict_param_setting, typecast_empty_string_to_nil, typecast_on_assignment, use_transactions. If they are not used, the object will default to whatever the model setting is.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#valuesObject (readonly)

The hash of attribute values. Keys are symbols with the names of the underlying database columns.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 512

def values
  @values
end

Instance Method Details

#==(obj) ⇒ Object Also known as: eql?

Compares model instances by values.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 560

def ==(obj)
  (obj.class == model) && (obj.values == @values)
end

#===(obj) ⇒ Object

If pk is not nil, true only if the objects have the same class and pk. If pk is nil, false.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 567

def ===(obj)
  pk.nil? ? false : (obj.class == model) && (obj.pk == pk)
end

#[](column) ⇒ Object

Returns value of the column's attribute.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 539

def [](column)
  @values[column]
end

#[]=(column, value) ⇒ Object

Sets the value for the given column. If typecasting is enabled for this object, typecast the value based on the column's type. If this a a new record or the typecasted value isn't the same as the current value for the column, mark the column as changed.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 547

def []=(column, value)
  # If it is new, it doesn't have a value yet, so we should
  # definitely set the new value.
  # If the column isn't in @values, we can't assume it is
  # NULL in the database, so assume it has changed.
  v = typecast_value(column, value)
  if new? || !@values.include?(column) || v != @values[column]
    changed_columns << column unless changed_columns.include?(column)
    @values[column] = v
  end
end

#associationsObject

The current cached associations. A hash with the keys being the association name symbols and the values being the associated object or nil (many_to_one), or the array of associated objects (*_to_many).


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# File 'lib/sequel/lib/sequel/model/base.rb', line 580

def associations
  @associations ||= {}
end

#autoincrementing_primary_keyObject

The autoincrementing primary key for this model object. Should be overridden if you have a composite primary key with one part of it being autoincrementing.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 587

def autoincrementing_primary_key
  primary_key
end

#changed_columnsObject

The columns that have been updated. This isn't completely accurate, see Model#[]=.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 593

def changed_columns
  @changed_columns ||= []
end

#deleteObject

Deletes and returns self. Does not run destroy hooks. Look into using destroy instead.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 599

def delete
  this.delete
  self
end

#destroyObject

Like delete but runs hooks before and after delete. If before_destroy returns false, returns false without deleting the object the the database. Otherwise, deletes the item from the database and returns self. Uses a transaction if use_transactions is true.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 609

def destroy
  use_transactions ? db.transaction{_destroy} : _destroy
end

#each(&block) ⇒ Object

Iterates through all of the current values using each.

Example:

Ticket.find(7).each { |k, v| puts "#{k} => #{v}" }

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# File 'lib/sequel/lib/sequel/model/base.rb', line 617

def each(&block)
  @values.each(&block)
end

#errorsObject

Returns the validation errors associated with this object.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 622

def errors
  @errors ||= Errors.new
end

#exists?Boolean

Returns true when current instance exists, false otherwise. Generally an object that isn't new will exist unless it has been deleted.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 629

def exists?
  this.count > 0
end

#hashObject

Value that should be unique for objects with the same class and pk (if pk is not nil), or the same class and values (if pk is nil).


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# File 'lib/sequel/lib/sequel/model/base.rb', line 635

def hash
  [model, pk.nil? ? @values.sort_by{|k,v| k.to_s} : pk].hash
end

#idObject

Returns value for the :id attribute, even if the primary key is not id. To get the primary key value, use #pk.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 641

def id
  @values[:id]
end

#initialize(values = {}, from_db = false) ⇒ Object

Creates new instance and passes the given values to set. If a block is given, yield the instance to the block unless from_db is true. This method runs the after_initialize hook after it has optionally yielded itself to the block.

Arguments:

  • values - should be a hash to pass to set.

  • from_db - should only be set by Model.load, forget it exists.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 524

def initialize(values = {}, from_db = false)
  if from_db
    @new = false
    @values = values
  else
    @values = {}
    @new = true
    set(values)
    changed_columns.clear 
    yield self if block_given?
  end
  after_initialize
end

#inspectObject

Returns a string representation of the model instance including the class name and values.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 647

def inspect
  "#<#{model.name} @values=#{inspect_values}>"
end

#keysObject

Returns the keys in values. May not include all column names.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 652

def keys
  @values.keys
end

#modified?Boolean

Whether this object has been modified since last saved, used by save_changes to determine whether changes should be saved. New values are always considered modified.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 659

def modified?
  new? || !changed_columns.empty?
end

#new?Boolean

Returns true if the current instance represents a new record.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 664

def new?
  @new
end

#pkObject

Returns the primary key value identifying the model instance. Raises an error if this model does not have a primary key. If the model has a composite primary key, returns an array of values.

Raises:


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# File 'lib/sequel/lib/sequel/model/base.rb', line 671

def pk
  raise(Error, "No primary key is associated with this model") unless key = primary_key
  key.is_a?(Array) ? key.map{|k| @values[k]} : @values[key]
end

#pk_hashObject

Returns a hash identifying the model instance. It should be true that:

Model[model_instance.pk_hash] === model_instance

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# File 'lib/sequel/lib/sequel/model/base.rb', line 679

def pk_hash
  model.primary_key_hash(pk)
end

#refreshObject

Reloads attributes from database and returns self. Also clears all cached association and changed_columns information. Raises an Error if the record no longer exists in the database.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 686

def refresh
  _refresh(this)
end

#reloadObject

Alias of refresh, but not aliased directly to make overriding in a plugin easier.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 691

def reload
  refresh
end

#save(*columns) ⇒ Object

Creates or updates the record, after making sure the record is valid. If the record is not valid, or before_save, before_create (if new?), or before_update (if !new?) return false, returns nil unless raise_on_save_failure is true (if it is true, it raises an error). Otherwise, returns self. You can provide an optional list of columns to update, in which case it only updates those columns.

Takes the following options:

  • :changed - save all changed columns, instead of all columns or the columns given

  • :transaction - set to false not to use a transaction

  • :validate - set to false not to validate the model before saving


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# File 'lib/sequel/lib/sequel/model/base.rb', line 708

def save(*columns)
  opts = columns.last.is_a?(Hash) ? columns.pop : {}
  return save_failure(:invalid) if opts[:validate] != false and !valid?
  use_transaction = opts.include?(:transaction) ? opts[:transaction] : use_transactions
  use_transaction ? db.transaction(opts){_save(columns, opts)} : _save(columns, opts)
end

#save_changesObject

Saves only changed columns if the object has been modified. If the object has not been modified, returns nil. If unable to save, returns false unless raise_on_save_failure is true.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 718

def save_changes
  save(:changed=>true) || false if modified? 
end

#set(hash) ⇒ Object

Updates the instance with the supplied values with support for virtual attributes, raising an exception if a value is used that doesn't have a setter method (or ignoring it if strict_param_setting = false). Does not save the record.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 726

def set(hash)
  set_restricted(hash, nil, nil)
end

#set_all(hash) ⇒ Object

Set all values using the entries in the hash, ignoring any setting of allowed_columns or restricted columns in the model.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 732

def set_all(hash)
  set_restricted(hash, false, false)
end

#set_except(hash, *except) ⇒ Object

Set all values using the entries in the hash, except for the keys given in except.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 738

def set_except(hash, *except)
  set_restricted(hash, false, except.flatten)
end

#set_only(hash, *only) ⇒ Object

Set the values using the entries in the hash, only if the key is included in only.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 744

def set_only(hash, *only)
  set_restricted(hash, only.flatten, false)
end

#thisObject

Returns (naked) dataset that should return only this instance.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 749

def this
  @this ||= model.dataset.filter(pk_hash).limit(1).naked
end

#update(hash) ⇒ Object

Runs set with the passed hash and runs save_changes (which runs any callback methods).


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# File 'lib/sequel/lib/sequel/model/base.rb', line 754

def update(hash)
  update_restricted(hash, nil, nil)
end

#update_all(hash) ⇒ Object

Update all values using the entries in the hash, ignoring any setting of allowed_columns or restricted columns in the model.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 760

def update_all(hash)
  update_restricted(hash, false, false)
end

#update_except(hash, *except) ⇒ Object

Update all values using the entries in the hash, except for the keys given in except.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 766

def update_except(hash, *except)
  update_restricted(hash, false, except.flatten)
end

#update_only(hash, *only) ⇒ Object

Update the values using the entries in the hash, only if the key is included in only.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 772

def update_only(hash, *only)
  update_restricted(hash, only.flatten, false)
end

#valid?Boolean

Validates the object and returns true if no errors are reported.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 783

def valid?
  errors.clear
  if before_validation == false
    save_failure(:validation)
    return false
  end
  validate
  after_validation
  errors.empty?
end

#validateObject

Validates the object. If the object is invalid, errors should be added to the errors attribute. By default, does nothing, as all models are valid by default.


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# File 'lib/sequel/lib/sequel/model/base.rb', line 779

def validate
end