odoo api裝飾器 one、model和multi區別

## @api.one

新api定義：

qty = fields.Integer(string="qty", compute="_get_qty")

@api.one
def _get_qty(self):
    self.qty = random.randint(1, 10)

one一般使用再無返回值，就算添加return也不會返回，也不會報錯，版本10以后逐漸淡化

## model

新api定義

@api.model
def create(self, vals):
    bom_obj = self.search([("product_tmpl_id", '=', vals.get('product_tmpl_id', None))])
    if bom_obj:
        raise UserError('該產品已存在相應的物料清單')
    return super(MrpBom, self).create(vals)

注意：這個方法的注釋是這樣的：修飾記錄樣式的方法，其中``self``是記錄集，但和內容無關緊要，只有模型相關

假如上面使用mutil裝飾就會出錯，提示參數個數的報錯， 此方法可以有返回值

def model(method):
    """ Decorate a record-style method where ``self`` is a recordset, but its
        contents is not relevant, only the model is. Such a method::

            @api.model
            def method(self, args):
                ...

        may be called in both record and traditional styles, like::

            # recs = model.browse(cr, uid, ids, context)
            recs.method(args)

            model.method(cr, uid, args, context=context)

        Notice that no ``ids`` are passed to the method in the traditional style.
    """
    method._api = 'model'
    return method

## mutil

新api定義

@api.multi
def search_recursively_line_product(self):
    product_ids = set()
    for rec in self:
        for bom_line in rec.bom_line_ids:
            product_ids.add(bom_line.product_id.id)
            product_tmpl_id = self.env['product.product'].browse(bom_line.product_id.id).product_tmpl_id.id
            bom_line_bom = self.search([('product_tmpl_id', '=', product_tmpl_id)])
            if bom_line_bom.bom_line_ids:
                product_ids |= bom_line_bom.search_recursively_line_product()
    return product_ids

注：mutil和one時對應的，可以返回一個或者回個記錄集

修飾一個記錄樣式的方法，其中``self``是一個記錄集，通常定義對記錄的操作

def multi(method):
    """ Decorate a record-style method where ``self`` is a recordset. The method
        typically defines an operation on records. Such a method::

            @api.multi
            def method(self, args):
                ...

        may be called in both record and traditional styles, like::

            # recs = model.browse(cr, uid, ids, context)
            recs.method(args)

            model.method(cr, uid, ids, args, context=context)
    """
    method._api = 'multi'
    return method