knowledge/attachment_zipped_download/readme/USAGE.md

1. Go to Settings > Technical > Database Structure > Attachments and select some files.
2. Go to Actions > Download and a zip file containing the selected files will be downloaded.

## For developer

You can reuse the IrAttachmentActionDownloadMixin on your favorite models:

from odoo import models


class StockPicking(models.Model):
    _name = "stock.picking"
    _inherit = ["stock.picking", "ir.attachment.action_download"]

Then you can add an action button on list view line or on the action button (when multiple lines are selected) to download all files:

<odoo>
    <!--
        add a button on list view to download all attachement present
        on the given transfert
    -->
    <record id="vpicktree" model="ir.ui.view">
        <field name="inherit_id" ref="stock.vpicktree"/>
        <field name="name">stock.picking.tree download attachments</field>
        <field name="model">stock.picking</field>
        <field name="arch" type="xml">
            <field name="json_popover" position="after">
                <button name="action_download_attachments"
                    type="object"
                    icon="fa-download"
                    string="Download attachment(s)"
                    aria-label="Download Proof documents"
                    class="float-right"/>
            </field>
        </field>
    </record>

    <!--
        Add "Download attachments" item in the Action menu when
        multiple records are selected
    -->
    <record id="action_download_picking_attachements" model="ir.actions.server">
        <field name="name">Download attachments</field>
        <field name="model_id" ref="stock.model_stock_picking"/>
        <field name="binding_model_id" ref="stock.model_stock_picking"/>
        <field name="binding_view_types">list</field>
        <field name="state">code</field>
        <field name="code">
            action = records.action_download_attachments()
        </field>
    </record>
</odoo>

Note

Even you will be able to generate a zip file with multiple document with the same name it's advice to overwrite _compute_zip_file_name to improve the name. When a slash (/) is present in the path it will create a directory. This example will create a directory per stock.picking using its name:

class IrAttachment(models.Model):
    _inherit = "ir.attachment"

    def _compute_zip_file_name(self):
        self.ensure_one()
        if self.res_model and self.res_model == "stock.picking":
            return (
                self.env[self.res_model]
                .browse(self.res_id)
                .display_name.replace("/", "-")
                + "/"
                + self.name
            )
        return super()._compute_zip_file_name()