Module: Sequel::Model::ClassMethods
- Defined in:
- lib/sequel/model/base.rb,
lib/sequel/model/plugins.rb
Overview
Class methods for Sequel::Model that implement basic model functionality.
-
All of the method names in Model::DATASET_METHODS have class methods created that call the Model’s dataset with the method of the same name with the given arguments.
Instance Attribute Summary collapse
-
#allowed_columns ⇒ Object
readonly
Which columns should be the only columns allowed in a call to set (default: not set, so all columns not otherwise restricted).
-
#dataset_method_modules ⇒ Object
readonly
Array of modules that extend this model’s dataset.
-
#dataset_methods ⇒ Object
readonly
Hash of dataset methods with method name keys and proc values that are stored so when the dataset changes, methods defined with def_dataset_method will be applied to the new dataset.
-
#plugins ⇒ Object
readonly
Array of plugins loaded by this class.
-
#primary_key ⇒ Object
readonly
The primary key for the class.
-
#raise_on_save_failure ⇒ Object
Whether to raise an error instead of returning nil on a failure to save/create/save_changes/etc due to a validation failure or a before_* hook returning false.
-
#raise_on_typecast_failure ⇒ Object
Whether to raise an error when unable to typecast data for a column (default: true).
-
#require_modification ⇒ Object
Whether to raise an error if an UPDATE or DELETE query related to a model instance does not modify exactly 1 row.
-
#restricted_columns ⇒ Object
readonly
Which columns are specifically restricted in a call to set/update/new/etc.
-
#simple_pk ⇒ Object
readonly
Should be the literal primary key column name if this Model’s table has a simple primary key, or nil if the model has a compound primary key or no primary key.
-
#simple_table ⇒ Object
readonly
Should be the literal table name if this Model’s dataset is a simple table (no select, order, join, etc.), or nil otherwise.
-
#strict_param_setting ⇒ Object
Whether new/set/update and their variants should raise an error if an invalid key is used.
-
#typecast_empty_string_to_nil ⇒ Object
Whether to typecast the empty string (”) to nil for columns that are not string or blob.
-
#typecast_on_assignment ⇒ Object
Whether to typecast attribute values on assignment (default: true).
-
#use_transactions ⇒ Object
Whether to use a transaction by default when saving/deleting records (default: true).
Instance Method Summary collapse
-
#[](*args) ⇒ Object
Returns the first record from the database matching the conditions.
-
#columns ⇒ Object
Returns the columns in the result set in their original order.
-
#create(values = {}, &block) ⇒ Object
Creates instance using new with the given values and block, and saves it.
-
#dataset ⇒ Object
Returns the dataset associated with the Model class.
-
#dataset=(ds) ⇒ Object
Alias of set_dataset.
-
#db ⇒ Object
Returns the database associated with the Model class.
-
#db=(db) ⇒ Object
Sets the database associated with the Model class.
-
#db_schema ⇒ Object
Returns the cached schema information if available or gets it from the database.
-
#def_dataset_method(*args, &block) ⇒ Object
If a block is given, define a method on the dataset (if the model has an associated dataset) with the given argument name using the given block as well as a method on the model that calls the dataset method.
-
#find(*args, &block) ⇒ Object
Finds a single record according to the supplied filter, e.g.:.
-
#find_or_create(cond) ⇒ Object
Like find but invokes create with given conditions when record does not exist.
-
#implicit_table_name ⇒ Object
Returns the implicit table name for the model class.
-
#inherited(subclass) ⇒ Object
If possible, set the dataset for the model subclass as soon as it is created.
-
#load(values) ⇒ Object
Initializes a model instance as an existing record.
-
#no_primary_key ⇒ Object
Mark the model as not having a primary key.
-
#primary_key_hash(value) ⇒ Object
Returns primary key attribute hash.
-
#qualified_primary_key_hash(value, qualifier = table_name) ⇒ Object
Return a hash where the keys are qualified column references.
-
#restrict_primary_key ⇒ Object
Restrict the setting of the primary key(s) inside new/set/update.
-
#restrict_primary_key? ⇒ Boolean
Whether or not setting the primary key inside new/set/update is restricted, true by default.
-
#set_allowed_columns(*cols) ⇒ Object
Set the columns to allow in new/set/update.
-
#set_dataset(ds, opts = {}) ⇒ Object
Sets the dataset associated with the Model class.
-
#set_primary_key(*key) ⇒ Object
Sets the primary key for this model.
-
#set_restricted_columns(*cols) ⇒ Object
Set the columns to restrict in new/set/update.
-
#subset(name, *args, &block) ⇒ Object
Defines a method that returns a filtered dataset.
-
#table_name ⇒ Object
Returns name of primary table for the dataset.
-
#unrestrict_primary_key ⇒ Object
Allow the setting of the primary key(s) inside new/set/update.
Instance Attribute Details
#allowed_columns ⇒ Object (readonly)
Which columns should be the only columns allowed in a call to set (default: not set, so all columns not otherwise restricted).
15 16 17 |
# File 'lib/sequel/model/base.rb', line 15 def allowed_columns @allowed_columns end |
#dataset_method_modules ⇒ Object (readonly)
Array of modules that extend this model’s dataset. Stored so that if the model’s dataset is changed, it will be extended with all of these modules.
20 21 22 |
# File 'lib/sequel/model/base.rb', line 20 def dataset_method_modules @dataset_method_modules end |
#dataset_methods ⇒ Object (readonly)
Hash of dataset methods with method name keys and proc values that are stored so when the dataset changes, methods defined with def_dataset_method will be applied to the new dataset.
25 26 27 |
# File 'lib/sequel/model/base.rb', line 25 def dataset_methods @dataset_methods end |
#plugins ⇒ Object (readonly)
Array of plugins loaded by this class
49 50 51 |
# File 'lib/sequel/model/plugins.rb', line 49 def plugins @plugins end |
#primary_key ⇒ Object (readonly)
The primary key for the class. Sequel can determine this automatically for many databases, but not all, so you may need to set it manually. If not determined automatically, the default is :id.
30 31 32 |
# File 'lib/sequel/model/base.rb', line 30 def primary_key @primary_key end |
#raise_on_save_failure ⇒ Object
Whether to raise an error instead of returning nil on a failure to save/create/save_changes/etc due to a validation failure or a before_* hook returning false.
35 36 37 |
# File 'lib/sequel/model/base.rb', line 35 def raise_on_save_failure @raise_on_save_failure end |
#raise_on_typecast_failure ⇒ Object
Whether to raise an error when unable to typecast data for a column (default: true). This should be set to false if you want to use validations to display nice error messages to the user (e.g. most web applications). You can use the validates_not_string validations (from either the validation_helpers or validation_class_methods standard plugins) in connection with option to check for typecast failures for columns that aren’t blobs or strings.
44 45 46 |
# File 'lib/sequel/model/base.rb', line 44 def raise_on_typecast_failure @raise_on_typecast_failure end |
#require_modification ⇒ Object
Whether to raise an error if an UPDATE or DELETE query related to a model instance does not modify exactly 1 row. If set to false, Sequel will not check the number of rows modified (default: true).
49 50 51 |
# File 'lib/sequel/model/base.rb', line 49 def require_modification @require_modification end |
#restricted_columns ⇒ Object (readonly)
Which columns are specifically restricted in a call to set/update/new/etc. (default: not set). Some columns are restricted regardless of this setting, such as the primary key column and columns in Model::RESTRICTED_SETTER_METHODS.
54 55 56 |
# File 'lib/sequel/model/base.rb', line 54 def restricted_columns @restricted_columns end |
#simple_pk ⇒ Object (readonly)
Should be the literal primary key column name if this Model’s table has a simple primary key, or nil if the model has a compound primary key or no primary key.
58 59 60 |
# File 'lib/sequel/model/base.rb', line 58 def simple_pk @simple_pk end |
#simple_table ⇒ Object (readonly)
Should be the literal table name if this Model’s dataset is a simple table (no select, order, join, etc.), or nil otherwise. This and simple_pk are used for an optimization in Model.[].
62 63 64 |
# File 'lib/sequel/model/base.rb', line 62 def simple_table @simple_table end |
#strict_param_setting ⇒ Object
Whether new/set/update and their variants should raise an error if an invalid key is used. A key is invalid if no setter method exists for that key or the access to the setter method is restricted (e.g. due to it being a primary key field). If set to false, silently skip any key where the setter method doesn’t exist or access to it is restricted.
69 70 71 |
# File 'lib/sequel/model/base.rb', line 69 def strict_param_setting @strict_param_setting end |
#typecast_empty_string_to_nil ⇒ Object
Whether to typecast the empty string (”) to nil for columns that are not string or blob. In most cases the empty string would be the way to specify a NULL SQL value in string form (nil.to_s == ”), and an empty string would not usually be typecast correctly for other types, so the default is true.
76 77 78 |
# File 'lib/sequel/model/base.rb', line 76 def typecast_empty_string_to_nil @typecast_empty_string_to_nil end |
#typecast_on_assignment ⇒ Object
Whether to typecast attribute values on assignment (default: true). If set to false, no typecasting is done, so it will be left up to the database to typecast the value correctly.
81 82 83 |
# File 'lib/sequel/model/base.rb', line 81 def typecast_on_assignment @typecast_on_assignment end |
#use_transactions ⇒ Object
Whether to use a transaction by default when saving/deleting records (default: true). If you are sending database queries in before_* or after_* hooks, you shouldn’t change the default setting without a good reason.
86 87 88 |
# File 'lib/sequel/model/base.rb', line 86 def use_transactions @use_transactions end |
Instance Method Details
#[](*args) ⇒ Object
Returns the first record from the database matching the conditions. If a hash is given, it is used as the conditions. If another object is given, it finds the first record whose primary key(s) match the given argument(s).
92 93 94 95 |
# File 'lib/sequel/model/base.rb', line 92 def [](*args) args = args.first if (args.size == 1) args.is_a?(Hash) ? dataset[args] : primary_key_lookup(args) end |
#columns ⇒ Object
Returns the columns in the result set in their original order. Generally, this will use the columns determined via the database schema, but in certain cases (e.g. models that are based on a joined dataset) it will use Dataset#columns to find the columns, which may be empty if the Dataset has no records.
102 103 104 |
# File 'lib/sequel/model/base.rb', line 102 def columns @columns || set_columns(dataset.naked.columns) end |
#create(values = {}, &block) ⇒ Object
Creates instance using new with the given values and block, and saves it.
107 108 109 |
# File 'lib/sequel/model/base.rb', line 107 def create(values = {}, &block) new(values, &block).save end |
#dataset ⇒ Object
Returns the dataset associated with the Model class. Raises an error if there is no associated dataset for this class.
113 114 115 |
# File 'lib/sequel/model/base.rb', line 113 def dataset @dataset || raise(Error, "No dataset associated with #{self}") end |
#dataset=(ds) ⇒ Object
Alias of set_dataset
118 119 120 |
# File 'lib/sequel/model/base.rb', line 118 def dataset=(ds) set_dataset(ds) end |
#db ⇒ Object
Returns the database associated with the Model class. If this model doesn’t have a database associated with it, assumes the superclass’s database, or the first object in Sequel::DATABASES. If no Sequel::Database object has been created, raises an error.
127 128 129 130 131 132 |
# File 'lib/sequel/model/base.rb', line 127 def db return @db if @db @db = self == Model ? DATABASES.first : superclass.db raise(Error, "No database associated with #{self}") unless @db @db end |
#db=(db) ⇒ Object
Sets the database associated with the Model class. If the model has an associated dataset, sets the model’s dataset to a dataset on the new database with the same options used by the current dataset.
138 139 140 141 |
# File 'lib/sequel/model/base.rb', line 138 def db=(db) @db = db set_dataset(db.dataset(@dataset.opts)) if @dataset end |
#db_schema ⇒ Object
Returns the cached schema information if available or gets it from the database.
145 146 147 |
# File 'lib/sequel/model/base.rb', line 145 def db_schema @db_schema ||= get_db_schema end |
#def_dataset_method(*args, &block) ⇒ Object
If a block is given, define a method on the dataset (if the model has an associated dataset) with the given argument name using the given block as well as a method on the model that calls the dataset method. Stores the method name and block so that it can be reapplied if the model’s dataset changes.
If a block is not given, define a method on the model for each argument that calls the dataset method of the same argument name.
156 157 158 159 160 161 162 163 164 165 |
# File 'lib/sequel/model/base.rb', line 156 def def_dataset_method(*args, &block) raise(Error, "No arguments given") if args.empty? if block_given? raise(Error, "Defining a dataset method using a block requires only one argument") if args.length > 1 meth = args.first @dataset_methods[meth] = block dataset.(meth, &block) if @dataset end args.each{|arg| instance_eval("def #{arg}(*args, &block); dataset.#{arg}(*args, &block) end", __FILE__, __LINE__) unless respond_to?(arg)} end |
#find(*args, &block) ⇒ Object
Finds a single record according to the supplied filter, e.g.:
Ticket.find :author => 'Sharon' # => record
You are encouraged to use Model.[] or Model.first instead of this method.
172 173 174 |
# File 'lib/sequel/model/base.rb', line 172 def find(*args, &block) filter(*args, &block).first end |
#find_or_create(cond) ⇒ Object
Like find but invokes create with given conditions when record does not exist.
178 179 180 |
# File 'lib/sequel/model/base.rb', line 178 def find_or_create(cond) find(cond) || create(cond) end |
#implicit_table_name ⇒ Object
Returns the implicit table name for the model class.
210 211 212 |
# File 'lib/sequel/model/base.rb', line 210 def implicit_table_name pluralize(underscore(demodulize(name))).to_sym end |
#inherited(subclass) ⇒ Object
If possible, set the dataset for the model subclass as soon as it is created. Also, make sure the inherited class instance variables are copied into the subclass.
185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 |
# File 'lib/sequel/model/base.rb', line 185 def inherited(subclass) super ivs = subclass.instance_variables.collect{|x| x.to_s} EMPTY_INSTANCE_VARIABLES.each{|iv| subclass.instance_variable_set(iv, nil) unless ivs.include?(iv.to_s)} INHERITED_INSTANCE_VARIABLES.each do |iv, dup| next if ivs.include?(iv.to_s) sup_class_value = instance_variable_get(iv) sup_class_value = sup_class_value.dup if dup == :dup && sup_class_value subclass.instance_variable_set(iv, sup_class_value) end unless ivs.include?("@dataset") db begin if self == Model || !@dataset subclass.set_dataset(subclass.implicit_table_name) unless subclass.name.empty? elsif @dataset subclass.set_dataset(@dataset.clone, :inherited=>true) end rescue nil end end end |
#load(values) ⇒ Object
Initializes a model instance as an existing record. This constructor is used by Sequel to initialize model instances when fetching records. load requires that values be a hash where all keys are symbols. It probably should not be used by external code.
218 219 220 |
# File 'lib/sequel/model/base.rb', line 218 def load(values) new(values, true) end |
#no_primary_key ⇒ Object
Mark the model as not having a primary key. Not having a primary key can cause issues, among which is that you won’t be able to update records.
224 225 226 |
# File 'lib/sequel/model/base.rb', line 224 def no_primary_key @simple_pk = @primary_key = nil end |
#primary_key_hash(value) ⇒ Object
Returns primary key attribute hash. If using a composite primary key value such be an array with values for each primary key in the correct order. For a standard primary key, value should be an object with a compatible type for the key. If the model does not have a primary key, raises an Error.
233 234 235 236 237 238 239 240 241 242 243 |
# File 'lib/sequel/model/base.rb', line 233 def primary_key_hash(value) raise(Error, "#{self} does not have a primary key") unless key = @primary_key case key when Array hash = {} key.each_with_index{|k,i| hash[k] = value[i]} hash else {key => value} end end |
#qualified_primary_key_hash(value, qualifier = table_name) ⇒ Object
Return a hash where the keys are qualified column references. Uses the given qualifier if provided, or the table_name otherwise.
247 248 249 250 251 |
# File 'lib/sequel/model/base.rb', line 247 def qualified_primary_key_hash(value, qualifier=table_name) h = primary_key_hash(value) h.to_a.each{|k,v| h[SQL::QualifiedIdentifier.new(qualifier, k)] = h.delete(k)} h end |
#restrict_primary_key ⇒ Object
Restrict the setting of the primary key(s) inside new/set/update. Because this is the default, this only make sense to use in a subclass where the parent class has used unrestrict_primary_key.
256 257 258 |
# File 'lib/sequel/model/base.rb', line 256 def restrict_primary_key @restrict_primary_key = true end |
#restrict_primary_key? ⇒ Boolean
Whether or not setting the primary key inside new/set/update is restricted, true by default.
262 263 264 |
# File 'lib/sequel/model/base.rb', line 262 def restrict_primary_key? @restrict_primary_key end |
#set_allowed_columns(*cols) ⇒ Object
Set the columns to allow in new/set/update. Using this means that any columns not listed here will not be modified. If you have any virtual setter methods (methods that end in =) that you want to be used in new/set/update, they need to be listed here as well (without the =).
It may be better to use (set|update)_only instead of this in places where only certain columns may be allowed.
273 274 275 |
# File 'lib/sequel/model/base.rb', line 273 def set_allowed_columns(*cols) @allowed_columns = cols end |
#set_dataset(ds, opts = {}) ⇒ Object
Sets the dataset associated with the Model class. ds can be a Symbol (specifying a table name in the current database), or a Dataset. If a dataset is used, the model’s database is changed to the given dataset. If a symbol is used, a dataset is created from the current database with the table name given. Other arguments raise an Error. Returns self.
This changes the row_proc of the given dataset to return model objects, extends the dataset with the dataset_method_modules, and defines methods on the dataset using the dataset_methods. It also attempts to determine the database schema for the model, based on the given dataset.
289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 |
# File 'lib/sequel/model/base.rb', line 289 def set_dataset(ds, opts={}) inherited = opts[:inherited] @dataset = case ds when Symbol @simple_table = db.literal(ds) db[ds] when Dataset @simple_table = nil @db = ds.db ds else raise(Error, "Model.set_dataset takes a Symbol or a Sequel::Dataset") end @dataset.row_proc = Proc.new{|r| load(r)} @require_modification = Sequel::Model.require_modification.nil? ? @dataset.provides_accurate_rows_matched? : Sequel::Model.require_modification if inherited @simple_table = superclass.simple_table @columns = @dataset.columns rescue nil else @dataset_method_modules.each{|m| @dataset.extend(m)} if @dataset_method_modules @dataset_methods.each{|meth, block| @dataset.(meth, &block)} if @dataset_methods end @dataset.model = self if @dataset.respond_to?(:model=) check_non_connection_error{@db_schema = (inherited ? superclass.db_schema : get_db_schema)} self end |
#set_primary_key(*key) ⇒ Object
Sets the primary key for this model. You can use either a regular or a composite primary key.
Example:
class Tagging < Sequel::Model
# composite key
set_primary_key [:taggable_id, :tag_id]
end
class Person < Sequel::Model
# regular key
set_primary_key :person_id
end
You can set it to nil to not have a primary key, but that cause certain things not to work, see no_primary_key.
332 333 334 335 336 |
# File 'lib/sequel/model/base.rb', line 332 def set_primary_key(*key) key = key.flatten @simple_pk = key.length == 1 ? db.literal(key.first) : nil @primary_key = (key.length == 1) ? key[0] : key end |
#set_restricted_columns(*cols) ⇒ Object
Set the columns to restrict in new/set/update. Using this means that attempts to call setter methods for the columns listed here will cause an exception or be silently skipped (based on the strict_param_setting setting. If you have any virtual # setter methods (methods that end in =) that you want not to be used in new/set/update, they need to be listed here as well (without the =).
It may be better to use (set|update)_except instead of this in places where only certain columns may be allowed.
346 347 348 |
# File 'lib/sequel/model/base.rb', line 346 def set_restricted_columns(*cols) @restricted_columns = cols end |
#subset(name, *args, &block) ⇒ Object
Defines a method that returns a filtered dataset. Subsets create dataset methods, so they can be chained for scoping. For example:
Topic.subset(:joes, :username.like('%joe%'))
Topic.subset(:popular){|o| o.num_posts > 100}
Topic.subset(:recent){|o| o.created_on > Date.today - 7}
Allows you to do:
Topic.joes.recent.popular
to get topics with a username that includes joe that have more than 100 posts and were created less than 7 days ago.
Both the args given and the block are passed to Dataset#filter.
367 368 369 |
# File 'lib/sequel/model/base.rb', line 367 def subset(name, *args, &block) def_dataset_method(name){filter(*args, &block)} end |
#table_name ⇒ Object
Returns name of primary table for the dataset.
372 373 374 |
# File 'lib/sequel/model/base.rb', line 372 def table_name dataset.first_source_alias end |
#unrestrict_primary_key ⇒ Object
Allow the setting of the primary key(s) inside new/set/update.
377 378 379 |
# File 'lib/sequel/model/base.rb', line 377 def unrestrict_primary_key @restrict_primary_key = false end |