Tryton

Domain

Domains represent a set of records. A domain is a list of none or more clauses. A clause is a condition, which returns true or false. A record belongs to a domain, when the final result of the list of clauses returns true.

Syntax

The definition of a simple domain with one clause is represented by this pattern:

domain = [(<field name>, <operator>, <operand>)]
<field name>

Is the name of a trytond.model.fields or a pyson statement, that evaluates to a string.

A field of type trytond.model.fields.Many2One or trytond.model.fields.Many2Many or trytond.model.fields.One2Many or trytond.model.fields.One2One or trytond.model.fields.Reference can be dereferenced to related models. This is illustrated by the following example:

domain = [('country.name', '=', 'Japan')]

The number of dots in a clause is not limited.

Warning

For trytond.model.fields.Reference, an extra ending clause is needed to define the target model to join, for example:

domain = [('origin.party.name', '=', 'John Doe', 'sale.sale')]
operator
Is an operator out of Domain Operators or a pyson statement, that evaluates to a domain operator string.
operand
Is an operand or a pyson statement. The type of operand depends on the kind of <field name>.

The definition of an empty domain is:

domain = []

An empty domain without clauses will always return all active records. A record is active, when its appropriate Model contains a Boolean field with name active, and set to true. When the appropriate Model does not contain a Boolean field with name active all records are returned.

A domain can be setup as a combination of clauses, like shown in this pattern:

domain = [
    ('field name1', 'operator1', 'operand1'),
    ('field name2', 'operator2', 'operand2'),
    ('field name3', 'operator3', 'operand3'),]

The single clauses are implicitly combined with a logical AND operation.

In the domain syntax it is possible to provide explicitly the combination operation of the clauses. These operations can be AND or OR. This is illustrated by the following pattern:

domain = [ 'OR', [
            ('field name1', 'operator1', 'operand1'),
            ('field name2', 'operator2', 'operand2'),
        ], [
            ('field name3', 'operator3', 'operand3'),
        ],]

Here the domain is evaluated like this: ((clause1 AND clause2) OR clause3). Please note that the AND operation is implicit assumed when no operator is given. While the OR operation must be given explicitly. The former pattern is equivalent to the following completely explicit domain definition:

domain = [ 'OR',
             [ 'AND', [
                     ('field name1', 'operator1', 'operand1'),
                 ], [
                     ('field name2', 'operator2', 'operand2'),
                 ],
             ], [
                 ('field name3', 'operator3', 'operand3'),
         ],]

Obviously the use of the implicit AND operation makes the code more readable.

Domain Operators

The following operators are allowed in the domain syntax. <field name>, <operator> and <operand> are dereferenced to their values. The description of each operator follows this pattern, unless otherwise noted:

(<field name>, <operator>, <operand>)

=

Is a parity operator. Returns true when <field name> equals to <operand>.

!=

Is an imparity operator. It is the negation of the = operator.

like

Is a pattern matching operator. Returns true when <field name> is contained in the pattern represented by <operand>.

In <operand> an underscore (_) matches any single character, a percent sign (%) matches any string with zero or more characters. To use _ or % as literal, use the backslash \ to escape them. All matching is case sensitive.

not like

Is a pattern matching operator. It is the negation of the like operator.

ilike

Is a pattern matching operator. The same use as like operator, but matching is case insensitive.

not ilike

Is a pattern matching operator. The negation of the ilike operator.

in

Is a list member operator. Returns true when <field name> is in <operand> list.

not in

Is a list non-member operator. The negation of the in operator.

<

Is a less than operator. Returns true for type string of <field name> when <field name> is alphabetically sorted before <operand>.

Returns true for type number of <field name> when <field name> is less than <operand>.

>

Is a greater than operator. Returns true for type string of <field name> when <field name> is alphabetically sorted after <operand>.

Returns true for type number of <field name> when <field name> is greater <operand>.

<=

Is a less than or equal operator. Returns the same as using the < operator, but also returns true when <field name> is equal to <operand>.

>=

Is a greater than or equal operator. Returns the same as using the > operator, but also returns true when <field name> is equal to <operand>.

child_of

Is a parent child comparison operator. In case <field name> is a one2many returns true, if <field name> is a child of <operand>. <field name> and <operand> are represented each by an id. In case <field name> is a many2many not linked to itself, the clause pattern extends to:

(<field name>, ['child_of'|'not_child_of'], <operand>, <parent field>)

Where <parent field> is the name of the field constituting the many2one on the target model.

not child_of

Is a parent child comparison operator. It is the negation of the child_of operator.

parent_of

Is a parent child comparison operator. It is the same as child_of operator but if <field name> is a parent of <operand>.

not parent_of

Is a parent child comparison operator. it is the negation of this parent_of operator.

where

Is a trytond.model.fields.One2Many / trytond.model.fields.Many2Many domain operator. It returns true for every row of the target model that match the domain specified as <operand>.

not where

Is a trytond.model.fields.One2Many / trytond.model.fields.Many2Many domain operator. It returns true for every row of the target model that does not match the domain specified as <operand>.