Message Boxes in OpenERP

Edit: This technique does not appear to work in Odoo/OpenERP 8

Being able to show a user a message is a pretty basic, important piece of functionality. It took me a while to figure out how to trigger a user-visible message from the server in OpenERP, but I eventually managed it. Given the answers on Stack Overflow, I figured I should share this valuable finding with the rest of the world.

To set the stage, I was writing code to cancel postage on packages at the click of a button in the package tree view. Sometimes the postage cannot be cancelled for one reason or another and the shipping server returns a message explaining why. In that case I wanted to display whatever message the shipping server was returning to the end user.

OpenERP 7 comes with two client actions that will result in a Growl-like message in the user’s browser: “action_warn” and “action_info.” They both take three parameters: “title,” “text,” and “sticky.” The first two are the title text and the message text, respectively, as strings. The third is a boolean indicating whether the message should remain on the screen until the user closes it by clicking the “x” in the corner of it. Setting this to false will result in the message fading away on its own after a few seconds.

To trigger these client actions from a server action, just have the server action return a dictionary like this one:

    'type': 'ir.actions.client',  
    'tag': 'action_warn',  
    'name': 'Failure',  
    'params': {  
       'title': 'Postage Cancellation Failed',  
       'text': 'Shipment is outside the void period.',  
       'sticky': True  

Here’s a fuller example for those of you who need more illustration:

from openerp.osv import fields, osv  
from import _

class growling_growler(osv.osv):  
    _name = "growling.growler"  
    _columns = {  
        'name': fields.char(  
            'Name', size=32, required=True  

    def growl(self, cr, uid, ids, context=None):  
        return {  
            'type': 'ir.actions.client',  
            'tag': 'action_info',  
            'name': _('Growl'),  
            'params': {  
                'title': _('Grr...'),  
                'text': _('I am growling at you!'),  
                'sticky': False  

And the XML:

<?xml version="1.0" encoding="UTF-8"?>
        <record id="growling_growler_tree"
            <field name="name">
            <field name="model">
            <field name="arch" type="xml">
<tree string='Growling Growlers'>
                    <field name='name'&#47;>
                    <button string="Growl!"
                            type="object" />