[IMP]13481: compute dynamic content using mako template mechanism and render it in preview-pdf generation for agreement, clause, recital, section, appendix

agreement/models/agreement_appendix.py

@@ -1,7 +1,7 @@
 # Copyright (C) 2018 - TODAY, Pavlov Media
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
-from odoo import fields, models
+from odoo import api, fields, models
 
 
 class AgreementAppendix(models.Model):
@@ -15,6 +15,9 @@ class AgreementAppendix(models.Model):
                              "The name is not.")
     sequence = fields.Integer(string="Sequence", default=10)
     content = fields.Html(string="Content")
+    dynamic_content = fields.Html(compute="_compute_dynamic_content",
+        string="Dynamic Content",
+        help='compute dynamic Content')
     agreement_id = fields.Many2one('agreement', string="Agreement",
                                    ondelete="cascade")
     active = fields.Boolean(
@@ -22,3 +25,15 @@ class AgreementAppendix(models.Model):
         default=True,
         help="If unchecked, it will allow you to hide this appendix without "
              "removing it.")
+
+    # compute the dynamic content for mako expression
+    @api.multi
+    def _compute_dynamic_content(self):
+        MailTemplates = self.env['mail.template']
+        for appendix in self:
+            lang = appendix.agreement_id and \
+                appendix.agreement_id.partner_id.lang or 'en_US'
+            content = \
+            MailTemplates.with_context(lang=lang).render_template(
+                appendix.content, 'agreement.appendix', appendix.id)
+            appendix.dynamic_content = content