[18.0][FIX] pos_config_logo: embed POS logo on the receipt

pos_config_logo/README.rst

@@ -47,6 +47,11 @@ This module is useful for a company that runs stores with different
 brandings. To have a logo from the main branch is weird for the customer
 of those branded stores.
 
+The 18.0 migration used an absolute ``web.base.url`` image URL for
+``pos.config.logo``. That requires a session and can show Odoo's camera
+placeholder. The receipt now embeds the logo as a data URI (16.0
+behaviour). See ``readme/CONTEXT.md``.
+
 Configuration
 =============
 
@@ -64,7 +69,7 @@ Usage
 =====
 
 When the cashier prints a receipt the point of sale logo will show up in
-the receipt.
+the receipt (embedded as a data URI).
 
 Bug Tracker
 ===========

pos_config_logo/models/pos_config.py

@@ -1,9 +1,14 @@
 # Copyright 2024 Tecnativa - David Vidal
 # License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
-from odoo import fields, models
+from odoo import api, fields, models
 
 
 class PosConfig(models.Model):
     _inherit = "pos.config"
 
     logo = fields.Binary()
+
+    @api.model
+    def _load_pos_data_fields(self, config_id):
+        fields = list(super()._load_pos_data_fields(config_id) or self._fields)
+        return list(dict.fromkeys([*fields, "logo"]))

pos_config_logo/readme/CONTEXT.md

@@ -1,2 +1,21 @@
 This module is useful for a company that runs stores with different brandings. To have
 a logo from the main branch is weird for the customer of those branded stores.
+
+## Receipt image (why it is embedded)
+
+16.0 put the POS logo on the ticket as a data URI after loading a
+**relative** ``/web/image?model=pos.config`` URL (same idea as the core
+company logo). The 18.0 migration switched to an absolute
+``{web.base.url}/web/image?model=pos.config`` URL.
+
+That URL needs a session cookie. Company logos are typically public;
+``pos.config.logo`` is not. If the browser host does not match
+``web.base.url`` (``localhost`` vs ``127.0.0.1``) or print runs without
+cookies, Odoo returns ``placeholder.png`` (camera icon) even when the
+alternative logo is set. Changing ``web.base.url`` only fixes one host.
+
+This module therefore embeds the binary already loaded on the POS as
+``data:image/…;base64,…``, with a relative ``/web/image`` fallback (never
+``_base_url``). That matches 16.0 and current Odoo receipt guidance:
+store the logo as a data URL instead of refetching ``/web/image`` when
+printing.

pos_config_logo/readme/CONTRIBUTORS.md

@@ -1,2 +1,3 @@
 - [Tecnativa](https://tecnativa.com)
     - David Vidal
+- Miguel Machado

pos_config_logo/readme/USAGE.md

@@ -1 +1,4 @@
-When the cashier prints a receipt the point of sale logo will show up in the receipt.
+When the cashier prints a receipt the point of sale logo will show up in
+the receipt, embedded as a data URI so preview/print does not depend on
+``web.base.url``. After changing the logo, close and reopen the POS so
+the client reloads ``pos.config``.

pos_config_logo/static/src/js/logo_src.esm.js

@@ -0,0 +1,39 @@
+function _guessImageMime(b64) {
+    if (b64.startsWith("/9j/")) {
+        return "image/jpeg";
+    }
+    if (b64.startsWith("R0lGOD")) {
+        return "image/gif";
+    }
+    if (b64.startsWith("UklGR")) {
+        return "image/webp";
+    }
+    return "image/png";
+}
+
+/**
+ * Build a receipt-safe src for the per-POS logo.
+ *
+ * 16.0 loaded ``/web/image?model=pos.config`` (relative) and converted it
+ * to a data URI via canvas (``config_logo_base64``) so the printed ticket did
+ * not depend on a later HTTP fetch. The 18.0 migration replaced that with
+ * ``web.base.url`` + ``/web/image?model=pos.config``, which returns Odoo's
+ * camera placeholder when the request has no session cookie (localhost vs
+ * 127.0.0.1, print preview). Company logos stay public; ``pos.config.logo``
+ * does not. Embed the binary already loaded into the POS, with a relative
+ * ``/web/image`` fallback (never an absolute ``_base_url``).
+ */
+export function posConfigLogoSrc(config) {
+    if (!config?.id || !config.logo) {
+        return false;
+    }
+    const raw = config.logo;
+    if (typeof raw === "string" && (raw.startsWith("data:") || raw.startsWith("/"))) {
+        return raw;
+    }
+    const b64 = String(raw).replace(/\s/g, "");
+    if (b64.length > 32) {
+        return `data:${_guessImageMime(b64)};base64,${b64}`;
+    }
+    return `/web/image?model=pos.config&id=${config.id}&field=logo`;
+}

pos_config_logo/static/src/js/models.esm.js

@@ -1,11 +1,13 @@
 import {PosStore} from "@point_of_sale/app/store/pos_store";
 import {patch} from "@web/core/utils/patch";
+import {posConfigLogoSrc} from "@pos_config_logo/js/logo_src.esm";
 
 patch(PosStore.prototype, {
     getReceiptHeaderData() {
         const result = super.getReceiptHeaderData(...arguments);
-        if (this.config.logo) {
-            result.config_logo = `${this.session._base_url}/web/image?model=pos.config&id=${this.config.id}&field=logo`;
+        const src = posConfigLogoSrc(this.config);
+        if (src) {
+            result.config_logo = src;
         }
         return result;
     },

pos_config_logo/tests/__init__.py

@@ -0,0 +1,4 @@
+# Copyright 2026 Miguel Machado
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+from . import test_pos_config

pos_config_logo/tests/test_pos_config.py

@@ -0,0 +1,13 @@
+# Copyright 2026 Miguel Machado
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).
+
+from odoo.tests import tagged
+
+from odoo.addons.point_of_sale.tests.common import TestPoSCommon
+
+
+@tagged("post_install", "-at_install")
+class TestPosConfigLogo(TestPoSCommon):
+    def test_load_pos_data_fields_includes_logo(self):
+        fields = self.env["pos.config"]._load_pos_data_fields(self.basic_config.id)
+        self.assertIn("logo", fields)