.. _ref-models-fields: .. module:: trytond.model.fields ====== Fields ====== Fields define the behavior of the data on model's record. Field options ============= The following arguments are available to all field types. All are optional except :attr:`Field.string`. ``string`` ---------- .. attribute:: Field.string A string for the label of the field. ``help`` -------- .. attribute:: Field.help A multi-line help string for the field. ``required`` ------------ .. attribute:: Field.required If ``True``, the field is not allowed to be empty. Default is ``False``. ``readonly`` ------------ .. attribute:: Field.readonly If ``True``, the field is not editable in the client. Default is ``False``. ``domain`` ---------- .. attribute:: Field.domain A :ref:`domain ` constraint that will be applied on the field value. ``states`` ---------- .. attribute:: Field.states A dictionary that defines dynamic states of the field and overrides the static one. Possible keys are ``required``, ``readonly`` and ``invisible``. The values are :class:`~trytond.pyson.PYSON` statements that will be evaluated with the values of the record. ``select`` ---------- .. attribute:: Field.select If true, the content of the field will be indexed. .. _ref-models-fields-on_change: ``on_change`` ------------- .. attribute:: Field.on_change A set of field names. If this attribute is set, the client will call the method ``on_change_`` of the model when the user changes the current field value and will give the values of each fields in this list. The method signature is:: on_change_() This method must return a dictionary with the values of fields to be updated. .. note:: The on_change_ methods are running in a rollbacked transaction. .. The set of field names could be filled by using the decorator :meth:`depends`. .. _ref-models-fields-on_change_with: ``on_change_with`` ------------------ .. attribute:: Field.on_change_with A set of field names. Same like :attr:`on_change`, but defined the other way around. If this attribute is set, the client will call the method ``on_change_with_`` of the model when the user changes one of the fields defined in the list and will give the values of each fields in this list. The method signature is:: on_change_with_() This method must return the new value of the field. .. note:: The on_change_with_ methods are running in a rollbacked transaction. .. The set of field names could be filled by using the decorator :meth:`depends`. ``depends`` ----------- .. attribute:: Field.depends A list of field names on which the current one depends. This means that the client will also read these fields even if they are not defined on the view. :attr:`Field.depends` is used per example to ensure that :class:`~trytond.pyson.PYSON` statement could be evaluated. ``context`` ----------- .. attribute:: Field.context A dictionary which will update the current context when opening a *relation field*. ``loading`` ----------- .. attribute:: Field.loading Define how the field must be loaded: ``lazy`` or ``eager``. ``name`` -------- .. attribute:: Field.name The name of the field. Instance methods: .. method:: Field.convert_domain(domain, tables, Model) Convert the simple :ref:`domain ` clause into a SQL expression or a new domain. Where ``tables`` is a nested dictionary containing the existing joins (and it could be updated to add new joins):: { None: (, None), 'party': { None: (
, ), 'addresses': { None: (
, ), }, }, } .. method:: Field.sql_format(value) Convert the value to use as parameter of SQL queries. .. method:: Field.sql_type() Return the namedtuple('SQLType', 'base type') which defines the SQL type to use for creation and casting. .. method:: Field.sql_column(table) Return the Column instance based on table. Default value ============= See :ref:`default value ` Ordering ======== A class method could be defined for each field which must return a list of SQL expression on which to order instead of the field. The method signature is:: order_(tables) Where ``tables`` is a nested dictionary, see :meth:`~Field.convert_domain`. Depends ======= .. method:: depends([\*fields[, methods]]) A decorator to define the field names on which the decorated method depends. The `methods` argument can be used to duplicate the field names from other fields. This is usefull if the decorated method calls another method. Field types =========== Boolean ------- .. class:: Boolean(string[, \**options]) A true/false field. Integer ------- .. class:: Integer(string[, \**options]) An integer field. BigInteger ---------- .. class:: BigInteger(string[, \**options]) A long integer field. Char ---- .. class:: Char(string[, size[, translate[, \**options]]]) A single line string field. :class:`Char` has two extra optional arguments: .. attribute:: Char.size The maximum length (in characters) of the field. The size is enforced at the storage level and in the client input. .. attribute:: Char.translate If true, the value of the field is translatable. The value readed and stored will depend on the ``language`` defined in the context. .. attribute:: Char.autocomplete A set of field names. If this attribute is set, the client will call the method ``autocomplete_`` of the model when the user changes one of those field value. The method signature is:: autocomplete_(values) This method must return a list of string that will populate the ComboboxEntry in the client. The set of field names could be filled by using the decorator :meth:`depends`. Text ---- .. class:: Text(string[, size[, translatable[, \**options]]]) A multi line string field. :class:`Text` has two extra optional arguments: .. attribute:: Text.size Same as :attr:`Char.size` .. attribute:: Text.translate Same as :attr:`Char.translate` Float ----- .. class:: Float(string[, digits[, \**options]]) A floating-point number field. It will be represented in Python by a ``float`` instance. :class:`Float` has one extra optional arguments: .. attribute:: Float.digits A tuple of two integers. The first integer defines the total of numbers in the integer part. The second integer defines the total of numbers in the decimal part. Integers can be replaced by a :class:`~trytond.pyson.PYSON` statement. Numeric ------- .. class:: Numeric(string[, digits[, \**options]]) A fixed-point number field. It will be represented in Python by a ``decimal.Decimal`` instance. :class:`Numeric` has one extra optional arguments: .. attribute:: Numeric.digits Same as :attr:`Float.digits` Date ---- .. class:: Date(string[, \**options]) A date, represented in Python by a ``datetime.date`` instance. DateTime -------- .. class:: DateTime(string[, format, \**options]) A date and time, represented in Python by a ``datetime.datetime`` instance. .. attribute:: DateTime.format A string format as used by strftime. This format will be used to display the time part of the field. The default value is `%H:%M:%S`. The value can be replaced by a :class:`~trytond.pyson.PYSON` statement. Timestamp --------- .. class:: Timestamp(string[, \**options]) A timestamp, represented in Python by a ``datetime.datetime`` instance. Time ---- .. class:: Time(string[, format, \**options]) A time, represented in Python by a ``datetime.time`` instance. .. attribute:: Time.format Same as :attr:`DateTime.format` Binary ------ .. class:: Binary(string[, \**options]) A binary field. It will be represented in Python by a ``str`` instance. :class:`Binary` has one extra optional argument: .. attribute:: Binary.filename Name of the field that holds the data's filename. Default value is an empty string, which means the data has no filename (in this case, the filename is hidden, and the "Open" button is hidden when the widget is set to "image"). Selection --------- .. class:: Selection(selection, string[, sort[, selection_change_with[, translate[, \**options]]]) A string field with limited values to choice. :class:`Selection` has one extra required argument: .. attribute:: Selection.selection A list of 2-tuples that looks like this:: [ ('M', 'Male'), ('F', 'Female'), ] The first element in each tuple is the actual value stored. The second element is the human-readable name. It can also be the name of a class method on the model, that will return an appropriate list. The signature of the method is:: selection() .. note:: The method is automaticly added to :attr:`trytond.model.Model._rpc` if not manually set. .. :class:`Selection` has two extra optional arguments: .. attribute:: Selection.sort If true, the choices will be sorted by human-readable value. Default value is ``True``. .. attribute:: Selection.selection_change_with A set of field names. If this attribute is set, the client will call the ``selection`` method of the model when the user changes on of the fields defined in the list and will give the values of each fields in the list. The ``selection`` method should be an instance method. The set of field names could be filled by using the decorator :meth:`depends`. .. attribute:: Selection.translate_selection If true, the human-readable values will be translated. Default value is ``True``. Reference --------- .. class:: Reference(string[, selection[, selection_change_with[, \**options]]) A field that refers to a record of a model. It will be represented in Python by a ``str`` instance like this:: ',' But a ``tuple`` can be used to search or set value. :class:`Reference` has one extra optional argument: .. attribute:: Reference.selection Same as :attr:`Selection.selection` but only for model name. .. attribute:: Reference.selection_change_with Same like :attr:`Selection.selection_change_with`. Many2One -------- .. class:: Many2One(model_name, string[, left[, right[, ondelete[, datetime_field[, \**options]]]]]) A many-to-one relation field. :class:`Many2One` has one extra required argument: .. attribute:: Many2One.model_name The name of the target model. :class:`Many2One` has some extra optional arguments: .. attribute:: Many2One.left The name of the field that stores the left value for the `Modified Preorder Tree Traversal`_. It only works if the :attr:`model_name` is the same then the model. .. _`Modified Preorder Tree Traversal`: http://en.wikipedia.org/wiki/Tree_traversal .. attribute:: Many2One.right The name of the field that stores the right value. See :attr:`left`. .. attribute:: Many2One.ondelete Define the behavior of the record when the target record is deleted. Allowed values are: - ``CASCADE``: it will try to delete the record. - ``RESTRICT``: it will prevent the deletion of the target record. - ``SET NULL``: it will empty the relation field. ``SET NULL`` is the default setting. .. note:: ``SET NULL`` will be override into ``RESTRICT`` if :attr:`~Field.required` is true. .. .. attribute:: Many2One.datetime_field If set, the target record will be read at the date defined by the datetime field name of the record. It is usually used in combination with :attr:`trytond.model.ModelSQL._history` to request a value for a given date and time on a historicized model. One2Many -------- .. class:: One2Many(model_name, field, string[, add_remove[, order[, datetime_field[, size[, \**options]]]]]) A one-to-many relation field. It requires to have the opposite :class:`Many2One` field or a :class:`Reference` field defined on the target model. This field accepts as written value a list of tuples like this: - ``('create', [{: value, ...}, ...])``: it will create new target records and link them to this one. - ``('write'[[, ids, ...], {: value, ...}, ...])``: it will write values to target ids. - ``('delete'[, ids, ...])``: it will delete the target ids. - ``('add'[, ids, ...])``: it will link the target ids to this record. - ``('remove'[, ids, ...])``: it will unlink the target ids from this record. - ``('copy', ids[, {: value, ...}])``: it will copy the target ids to this record. Optional field names and values may be added to override some of the fields of the copied records. :class:`One2Many` has some extra required arguments: .. attribute:: One2Many.model_name The name of the target model. .. attribute:: One2Many.field The name of the field that handles the opposite :class:`Many2One` or :class:`Reference`. :class:`One2Many` has some extra optional arguments: .. attribute:: One2Many.add_remove A :ref:`domain ` to select records to add. If set, the client will allow to add/remove existing records instead of only create/delete. .. attribute:: One2Many.order A list of tuple defining the default order of the records like for :attr:`trytond.model.ModelSQL._order`. .. attribute:: One2Many.datetime_field Same as :attr:`Many2One.datetime_field` .. attribute:: One2Many.size An integer or a PYSON expression denoting the maximum number of records allowed in the relation. Many2Many --------- .. class:: Many2Many(relation_name, origin, target, string[, order[, datetime_field[, size[, \**options]]]]) A many-to-many relation field. It requires to have the opposite origin :class:`Many2One` field or a:class:`Reference` field defined on the relation model and a :class:`Many2One` field pointing to the target. This field accepts as written value a list of tuples like the :class:`One2Many`. :class:`Many2Many` has some extra required arguments: .. attribute:: Many2Many.relation_name The name of the relation model. .. attribute:: Many2Many.origin The name of the field that has the :class:`Many2One` or :class:`Reference` to the record. .. attribute:: Many2Many.target The name of the field that has the :class:`Many2One` to the target record. .. note:: A :class:`Many2Many` field can be used on a simple :class:`~trytond.model.ModelView`, like in a :class:`~trytond.wizard.Wizard`. For this, :attr:`~Many2Many.relation_name` is set to the target model and :attr:`~Many2Many.origin` and :attr:`~Many2Many.target` are set to `None`. .. :class:`Many2Many` has some extra optional arguments: .. attribute:: Many2Many.order Same as :attr:`One2Many.order` .. attribute:: Many2Many.datetime_field Same as :attr:`Many2One.datetime_field` .. attribute:: Many2Many.size An integer or a PYSON expression denoting the maximum number of records allowed in the relation. Instance methods: .. method:: Many2Many.get_target() Return the target :class:`~trytond.model.Model`. One2One ------- .. class:: One2One(relation_name, origin, target, string[, datetime_field[, \**options]]) A one-to-one relation field. .. warning:: It is on the relation_name :class:`~trytond.model.Model` that the unicity of the couple (origin, target) must be checked. .. .. attribute:: One2One.datetime_field Same as :attr:`Many2One.datetime_field` Instance methods: .. method:: One2One.get_target() Return the target :class:`~trytond.model.Model`. Function -------- .. class:: Function(field, getter[, setter[, searcher]]) A function field can emulate any other given `field`. :class:`Function` has a required argument: .. attribute:: Function.getter The name of the classmethod or instance of the :class:`~trytond.model.Model` for getting values. The signature of the classmethod is:: getter(instances, name) where `name` is the name of the field, and it must return a dictionary with a value for each instance. Or the signature of the classmethod is:: getter(instances, names) where `names` is a list of name fields, and it must return a dictionary containing for each names a dictionary with a value for each instance. The signature of the instancemethod is:: getter(name) where `name` is the name of the field, and it must return the value. :class:`Function` has some extra optional arguments: .. attribute:: Function.setter The name of the classmethod of the :class:`~trytond.model.Model` to set the value. The signature of the method id:: setter(ids, name, value) where `name` is the name of the field and `value` the value to set. .. attribute:: Function.searcher The name of the classmethod of the :class:`~trytond.model.Model` to search on the field. The signature of the method is:: searcher(name, clause) where `name` is the name of the field and `clause` is a :ref:`domain clause `. It must return a list of :ref:`domain ` clauses but the ``operand`` can be a SQL query. Instance methods: .. method:: Function.get(ids, model, name[, values]) Call the :attr:`~Function.getter` classmethod where `model` is the :class:`~trytond.model.Model` instance of the field, `name` is the name of the field. .. method:: Function.set(ids, model, name, value) Call the :attr:`~Function.setter` classmethod where `model` is the :class:`~trytond.model.Model` instance of the field, `name` is the name of the field, `value` is the value to set. .. method:: Function.search(model, name, clause) Call the :attr:`~Function.searcher` classmethod where `model` is the :class:`~trytond.model.Model` instance of the field, `name` is the name of the field, `clause` is a clause of :ref:`domain `. Property -------- .. class:: Property(field) A property field that is like a :class:`Function` field but with predifined :attr:`~Function.getter`, :attr:`~Function.setter` and :attr:`~Function.searcher` that use the :class:`~trytond.model.ModelSQL` `ir.property` to store values. Instance methods: .. method:: Property.get(ids, model, name[, values]) Same as :meth:`Function.get`. .. method:: Property.set(ids, model, name, value) Same as :meth:`Function.set`. .. method:: Property.search(model, name, clause) Same as :meth:`Function.search`. Dict ---- .. class:: Dict(schema_model[, \**options]) A dictionary field with predefined keys. :class:`Dict` has one extra required argument: .. attribute:: Dict.schema_model The name of the :class:`DictSchemaMixin` model that stores the definition of keys.