Allow user to select converter for each substitutions

Added a custom converter image

converter.py

+import base64
+from typing import Any, Dict, Optional
+
+from odoo import models
+from odoo.tools.mimetypes import guess_mimetype
+
+from odoo.addons.converter import Converter
+
+
+class Image(Converter):
+    def __init__(self, fieldname):
+        self.fieldname = fieldname
+
+    def odoo_to_message(
+        self, instance: models.Model, ctx: Optional[Dict] = None
+    ) -> Any:
+        value = getattr(instance, self.fieldname)
+
+        if not value:
+            return {}
+
+        content = base64.b64decode(value)
+        mimetype = guess_mimetype(content)
+
+        return {"body": value.decode("ascii"), "mime-type": mimetype}

models/ir_actions_report.py

-import ast
 import logging
 import time
 
 from odoo import _, api, fields, models
@@ -2,7 +1,9 @@
 import logging
 import time
 
 from odoo import _, api, fields, models
+from odoo.addons import converter
+from odoo.addons.redner.utils.formats import Formats
 from odoo.exceptions import ValidationError
 from odoo.tools.safe_eval import safe_eval
 
@@ -6,7 +7,7 @@
 from odoo.exceptions import ValidationError
 from odoo.tools.safe_eval import safe_eval
 
-from odoo.addons.redner.utils.formats import Formats
+from ..converter import Image
 
 _logger = logging.getLogger(__name__)
 
@@ -132,6 +133,6 @@
         return metadata_values
 
     def get_report_data(self, res_id):
-        # Get redner template values
-        values_sent_to_redner = {}
+        if not res_id:
+            return {}
 
@@ -137,7 +138,4 @@
 
-        if not res_id:
-            return values_sent_to_redner
-
-        Template = self.env["mail.template"].with_context(safe=True)
+        d = {}
 
         for sub in self.substitution_ids:
@@ -142,11 +140,11 @@
 
         for sub in self.substitution_ids:
-            value = Template._render_template(sub.value, self.model, res_id)
-            if sub.deserialize:
-                value = ast.literal_eval(value)
-
-            varpath = sub.keyword.split(".")
-
-            if len(varpath) > 1:
-                varpath, varname = varpath[:-1], varpath[-1]
+            if sub.converter == "mail_template":
+                conv = converter.MailTemplate(sub.value, False)
+            elif sub.converter == "mail_template+deserialize":
+                conv = converter.MailTemplate(sub.value, True)
+            elif sub.converter == "field":
+                conv = converter.Field(sub.value)
+            elif sub.converter == "image":
+                conv = Image(sub.value)
             else:
@@ -152,3 +150,6 @@
             else:
-                varpath, varname = [], varpath[0]
+                raise ValidationError(
+                    _("invalid converter type: %s") % sub.converter
+                )
+            d[sub.keyword] = conv
 
@@ -154,5 +155,3 @@
 
-            d = values_sent_to_redner
-            for name in varpath:
-                d = d.setdefault(name, {})
+        conv = converter.Model("", d)
 
@@ -158,6 +157,7 @@
 
-            d[varname] = value
-        return values_sent_to_redner
+        instance = self.env[self.model].browse(res_id)
+
+        return conv.odoo_to_message(instance)
 
     def render_redner(self, res_ids, data):
         self.ensure_one()

models/redner_substitution.py

@@ -2,8 +2,7 @@
 
 
 class Substitution(models.Model):
-    """ Substitution values for a Redner email message
-    """
+    """Substitution values for a Redner email message"""
 
     _name = "redner.substitution"
 
@@ -34,3 +33,12 @@
         help="Send this to your redner server and you will "
         "get a nice html output ready to be sent by email.",
     )
+
+    converter = fields.Selection(
+        selection=[
+            ("mail_template", "Template"),
+            ("mail_template+deserialize", "Template + Deserialize"),
+            ("field", "Field"),
+            ("image", "Image"),
+        ]
+    )

views/ir_actions_report.xml

@@ -30,4 +30,5 @@
                         <field name="substitution_ids" nolabel="1">
                             <tree editable="top">
                                 <field name="keyword"/>
+                                <field name="converter" />
                                 <field name="value"/>
@@ -33,5 +34,4 @@
                                 <field name="value"/>
-                                <field name="deserialize" />
                             </tree>
                         </field>
                     </group>