Module | Sequel::Model::ClassMethods |
In: |
lib/sequel/model/base.rb
lib/sequel/model/plugins.rb |
Class methods for Sequel::Model that implement basic model functionality.
allowed_columns | [R] | 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 | [R] | 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. |
dataset_methods | [R] | 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 | [R] | Array of plugins loaded by this class |
primary_key | [R] | 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. |
raise_on_save_failure | [RW] | 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 | [RW] | 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. |
restricted_columns | [R] | 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. |
simple_pk | [R] | 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 | [R] | 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.[]. |
strict_param_setting | [RW] | 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. |
typecast_empty_string_to_nil | [RW] | 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. |
typecast_on_assignment | [RW] | 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. |
use_transactions | [RW] | 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. |
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).
# File lib/sequel/model/base.rb, line 87 87: def [](*args) 88: args = args.first if (args.size == 1) 89: args.is_a?(Hash) ? dataset[args] : primary_key_lookup(args) 90: end
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.
# File lib/sequel/model/base.rb, line 97 97: def columns 98: @columns || set_columns(dataset.naked.columns) 99: end
Creates instance using new with the given values and block, and saves it.
# File lib/sequel/model/base.rb, line 102 102: def create(values = {}, &block) 103: new(values, &block).save 104: end
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.
# File lib/sequel/model/base.rb, line 117 117: def db 118: return @db if @db 119: @db = self == Model ? DATABASES.first : superclass.db 120: raise(Error, "No database associated with #{self}") unless @db 121: @db 122: end
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.
# File lib/sequel/model/base.rb, line 128 128: def db=(db) 129: @db = db 130: set_dataset(db.dataset(@dataset.opts)) if @dataset 131: end
Returns the cached schema information if available or gets it from the database.
# File lib/sequel/model/base.rb, line 135 135: def db_schema 136: @db_schema ||= get_db_schema 137: end
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.
# File lib/sequel/model/base.rb, line 146 146: def def_dataset_method(*args, &block) 147: raise(Error, "No arguments given") if args.empty? 148: if block_given? 149: raise(Error, "Defining a dataset method using a block requires only one argument") if args.length > 1 150: meth = args.first 151: @dataset_methods[meth] = block 152: dataset.meta_def(meth, &block) if @dataset 153: end 154: args.each{|arg| instance_eval("def #{arg}(*args, &block); dataset.#{arg}(*args, &block) end", __FILE__, __LINE__) unless respond_to?(arg)} 155: end
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.
# File lib/sequel/model/base.rb, line 162 162: def find(*args, &block) 163: filter(*args, &block).first 164: end
Returns the implicit table name for the model class.
# File lib/sequel/model/base.rb, line 199 199: def implicit_table_name 200: pluralize(underscore(demodulize(name))).to_sym 201: end
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.
# File lib/sequel/model/base.rb, line 175 175: def inherited(subclass) 176: ivs = subclass.instance_variables.collect{|x| x.to_s} 177: EMPTY_INSTANCE_VARIABLES.each{|iv| subclass.instance_variable_set(iv, nil) unless ivs.include?(iv.to_s)} 178: INHERITED_INSTANCE_VARIABLES.each do |iv, dup| 179: next if ivs.include?(iv.to_s) 180: sup_class_value = instance_variable_get(iv) 181: sup_class_value = sup_class_value.dup if dup == :dup && sup_class_value 182: subclass.instance_variable_set(iv, sup_class_value) 183: end 184: unless ivs.include?("@dataset") 185: db 186: begin 187: if self == Model || !@dataset 188: subclass.set_dataset(subclass.implicit_table_name) unless subclass.name.empty? 189: elsif @dataset 190: subclass.set_dataset(@dataset.clone, :inherited=>true) 191: end 192: rescue 193: nil 194: end 195: end 196: end
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.
# File lib/sequel/model/base.rb, line 207 207: def load(values) 208: new(values, true) 209: end
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.
# File lib/sequel/model/base.rb, line 213 213: def no_primary_key 214: @simple_pk = @primary_key = nil 215: end
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.
# File lib/sequel/model/base.rb, line 222 222: def primary_key_hash(value) 223: raise(Error, "#{self} does not have a primary key") unless key = @primary_key 224: case key 225: when Array 226: hash = {} 227: key.each_with_index{|k,i| hash[k] = value[i]} 228: hash 229: else 230: {key => value} 231: end 232: end
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.
# File lib/sequel/model/base.rb, line 237 237: def restrict_primary_key 238: @restrict_primary_key = true 239: end
Whether or not setting the primary key inside new/set/update is restricted, true by default.
# File lib/sequel/model/base.rb, line 243 243: def restrict_primary_key? 244: @restrict_primary_key 245: end
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.
# File lib/sequel/model/base.rb, line 254 254: def set_allowed_columns(*cols) 255: @allowed_columns = cols 256: end
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.
# File lib/sequel/model/base.rb, line 270 270: def set_dataset(ds, opts={}) 271: inherited = opts[:inherited] 272: @dataset = case ds 273: when Symbol 274: @simple_table = db.literal(ds) 275: db[ds] 276: when Dataset 277: @simple_table = nil 278: @db = ds.db 279: ds 280: else 281: raise(Error, "Model.set_dataset takes a Symbol or a Sequel::Dataset") 282: end 283: @dataset.row_proc = Proc.new{|r| load(r)} 284: if inherited 285: @simple_table = superclass.simple_table 286: @columns = @dataset.columns rescue nil 287: else 288: @dataset_method_modules.each{|m| @dataset.extend(m)} if @dataset_method_modules 289: @dataset_methods.each{|meth, block| @dataset.meta_def(meth, &block)} if @dataset_methods 290: end 291: @dataset.model = self if @dataset.respond_to?(:model=) 292: begin 293: @db_schema = (inherited ? superclass.db_schema : get_db_schema) 294: rescue Sequel::DatabaseConnectionError 295: raise 296: rescue 297: nil 298: end 299: self 300: end
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.
# File lib/sequel/model/base.rb, line 319 319: def set_primary_key(*key) 320: @simple_pk = key.length == 1 ? db.literal(key.first) : nil 321: @primary_key = (key.length == 1) ? key[0] : key.flatten 322: end
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.
# File lib/sequel/model/base.rb, line 332 332: def set_restricted_columns(*cols) 333: @restricted_columns = cols 334: end
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.
# File lib/sequel/model/base.rb, line 353 353: def subset(name, *args, &block) 354: def_dataset_method(name){filter(*args, &block)} 355: end