I am using Odoo v.11.

I was trying to customize the search bar for my model, so that the user can look for a string matching the name or the description:

        <record model="ir.ui.view" id="course_search_view">
            <field name="name">course.search</field>
            <field name="model">openacademy.course</field>
            <field name="arch" type="xml">
                <search>
                    <field name="name"/>
                    <field name="description"/>
                </search>
            </field>
 </record>

This seems to work, but the user has to specify if he's looking for the name or the description. Instead, I'd like that the user could search for a string, and the software should return every record matching that string in the name or description.

My idea was to define a computed field in the model, as the simple concatenation of field+" "+description:

    
    text_data = fields.Char(string="Textual data", compute='_text_data')

    @api.depends('name', 'description')
    def _text_data(self):
        for r in self:
            r.text_data = str(r.name)+" "+str(r.description) 

...and setup the search box to look for that field:

        <record model="ir.ui.view" id="course_search_view">
            <field name="name">course.search</field>
            <field name="model">openacademy.course</field>
            <field name="arch" type="xml">
                <search>
                    <field name="text_data"/>
                </search>
            </field>
        </record>

But this does not appear to work: the search always succeed, and all the records are returned even if the search string appears nowhere in the names and descriptions...

Am I doing something wrong?

Thanks in advance for any help.