~openerp-community/openobject-doc/ksa-openobject-doc-6.0

.. i18n: There are two possible ways to do this kind of inheritance. Both ways result in a new class of data, which holds parent fields and behaviour as well as additional fielda and behaviour, but they differ in heavy programatical consequences.

There are two possible ways to do this kind of inheritance. Both ways result in a new class of data, which holds parent fields and behaviour as well as additional fielda and behaviour, but they differ in heavy programatical consequences.

.. i18n: While Example 1 creates a new subclass "custom_material" that may be "seen" or "used" by any view or tree which handles "network.material", this will not be the case for Example 2.

While Example 1 creates a new subclass "custom_material" that may be "seen" or "used" by any view or tree which handles "network.material", this will not be the case for Example 2.

.. i18n: This is due to the table (other.material) the new subclass is operating on, which will never be recognized by previous "network.material" views or trees.

This is due to the table (other.material) the new subclass is operating on, which will never be recognized by previous "network.material" views or trees.

.. i18n: Example 1::

.. i18n:

.. i18n: class custom_material(osv.osv):

.. i18n: _name = 'network.material'

.. i18n: _inherit = 'network.material'

.. i18n: _columns = {

.. i18n: 'manuf_warranty': fields.boolean('Manufacturer warranty?'),

.. i18n: }

.. i18n: _defaults = {

.. i18n: 'manuf_warranty': lambda *a: False,

.. i18n: }

.. i18n: custom_material()

Example 1::

class custom_material(osv.osv):

_name = 'network.material'

_inherit = 'network.material'

_columns = {

'manuf_warranty': fields.boolean('Manufacturer warranty?'),

}

_defaults = {

'manuf_warranty': lambda *a: False,

}

custom_material()

.. i18n: .. tip:: Notice

.. i18n:

.. i18n: _name == _inherit

.. tip:: Notice

_name == _inherit

.. i18n: In this example, the 'custom_material' will add a new field 'manuf_warranty' to the object 'network.material'. New instances of this class will be visible by views or trees operating on the superclasses table 'network.material'.

In this example, the 'custom_material' will add a new field 'manuf_warranty' to the object 'network.material'. New instances of this class will be visible by views or trees operating on the superclasses table 'network.material'.

.. i18n: This inheritancy is usually called "class inheritance" in Object oriented design. The child inherits data (fields) and behavior (functions) of his parent.

100

101

102

This inheritancy is usually called "class inheritance" in Object oriented design. The child inherits data (fields) and behavior (functions) of his parent.

103

104

.. i18n: Example 2::

105

.. i18n:

106

.. i18n: class other_material(osv.osv):

107

.. i18n: _name = 'other.material'

108

.. i18n: _inherit = 'network.material'

109

.. i18n: _columns = {

110

.. i18n: 'manuf_warranty': fields.boolean('Manufacturer warranty?'),

111

.. i18n: }

112

.. i18n: _defaults = {

113

.. i18n: 'manuf_warranty': lambda *a: False,

114

.. i18n: }

115

.. i18n: other_material()

116

117

118

Example 2::

119

120

class other_material(osv.osv):

121

_name = 'other.material'

122

_inherit = 'network.material'

123

_columns = {

124

'manuf_warranty': fields.boolean('Manufacturer warranty?'),

125

}

126

_defaults = {

127

'manuf_warranty': lambda *a: False,

128

}

129

other_material()

130

131

.. i18n: .. tip:: Notice

132

.. i18n:

133

.. i18n: _name != _inherit

134

135

136

.. tip:: Notice

137

138

_name != _inherit

139

140

.. i18n: In this example, the 'other_material' will hold all fields specified by 'network.material' and it will additionally hold a new field 'manuf_warranty'. All those fields will be part of the table 'other.material'. New instances of this class will therefore never been seen by views or trees operating on the superclasses table 'network.material'.

141

142

143

In this example, the 'other_material' will hold all fields specified by 'network.material' and it will additionally hold a new field 'manuf_warranty'. All those fields will be part of the table 'other.material'. New instances of this class will therefore never been seen by views or trees operating on the superclasses table 'network.material'.

144

145

.. i18n: This type of inheritancy is known as "inheritance by prototyping" (e.g. Javascript), because the newly created subclass "copies" all fields from the specified superclass (prototype). The child inherits data (fields) and behavior (functions) of his parent.

146

147

148

This type of inheritancy is known as "inheritance by prototyping" (e.g. Javascript), because the newly created subclass "copies" all fields from the specified superclass (prototype). The child inherits data (fields) and behavior (functions) of his parent.

149

150

.. i18n: Inheritance by Delegation

151

.. i18n: -------------------------

152

153

154

Inheritance by Delegation

155

-------------------------

156

157

.. i18n: **Syntax :**::

158

.. i18n:

159

.. i18n: class tiny_object(osv.osv)

160

.. i18n: _name = 'tiny.object'

161

.. i18n: _table = 'tiny_object'

162

.. i18n: _inherits = { 'tiny.object_a' : 'name_col_a', 'tiny.object_b' : 'name_col_b',

163

.. i18n: ..., 'tiny.object_n' : 'name_col_n' }

164

.. i18n: (...)

165

166

167

**Syntax :**::

168

169

class tiny_object(osv.osv)

170

_name = 'tiny.object'

171

_table = 'tiny_object'

172

_inherits = { 'tiny.object_a' : 'name_col_a', 'tiny.object_b' : 'name_col_b',

173

..., 'tiny.object_n' : 'name_col_n' }

174

(...)

175

176

.. i18n: The object 'tiny.object' inherits from all the columns and all the methods from the n objects 'tiny.object_a', ..., 'tiny.object_n'.

177

178

179

The object 'tiny.object' inherits from all the columns and all the methods from the n objects 'tiny.object_a', ..., 'tiny.object_n'.

180

181

.. i18n: To inherit from multiple tables, the technique consists in adding one column to the table tiny_object per inherited object. This column will store a foreign key (an id from another table). The values *'name_col_a' 'name_col_b' ... 'name_col_n'* are of type string and determine the title of the columns in which the foreign keys from 'tiny.object_a', ..., 'tiny.object_n' are stored.

182

183

184

To inherit from multiple tables, the technique consists in adding one column to the table tiny_object per inherited object. This column will store a foreign key (an id from another table). The values *'name_col_a' 'name_col_b' ... 'name_col_n'* are of type string and determine the title of the columns in which the foreign keys from 'tiny.object_a', ..., 'tiny.object_n' are stored.

185

186

.. i18n: This inheritance mechanism is usually called " *instance inheritance* " or " *value inheritance* ". A resource (instance) has the VALUES of its parents.

187

188

189

This inheritance mechanism is usually called " *instance inheritance* " or " *value inheritance* ". A resource (instance) has the VALUES of its parents.

Older »