Lazy import html2text and weasyprint

modules/marketing_automation/marketing_automation.py

@@ -11,12 +11,6 @@ from urllib.parse import (
     parse_qsl, quote, urlencode, urljoin, urlsplit, urlunsplit)
 
 from dateutil.relativedelta import relativedelta
-
-try:
-    import html2text
-except ImportError:
-    html2text = None
-
 from genshi.core import END, START, Attrs, QName
 from genshi.template import MarkupTemplate
 from genshi.template import TemplateError as GenshiTemplateError
@@ -31,7 +25,7 @@ from trytond.model import (
     fields)
 from trytond.pool import Pool
 from trytond.pyson import Eval, If, PYSONDecoder, TimeDelta
-from trytond.report import Report
+from trytond.report import Report, html_to_text
 from trytond.sendmail import SMTPDataManager, send_message_transactional
 from trytond.tools import grouped_slice, pairwise_longest, reduce_ids
 from trytond.tools.chart import sparkline
@@ -750,9 +744,7 @@ class Activity(
         set_from_header(msg, from_, sender or from_)
         msg['To'] = to
         msg['Subject'] = subject
-        if html2text:
-            converter = html2text.HTML2Text()
-            content_text = converter.handle(content)
+        if content_text := html_to_text(content):
             msg.add_alternative(content_text, subtype='plain')
         if msg.is_multipart():
             msg.add_alternative(content, subtype='html')

modules/marketing_email/marketing.py

@@ -14,11 +14,6 @@ from genshi.template import TemplateError as GenshiTemplateError
 from sql import Literal
 from sql.aggregate import Count
 
-try:
-    import html2text
-except ImportError:
-    html2text = None
-
 import trytond.config as config
 from trytond.i18n import gettext
 from trytond.ir.session import token_hex
@@ -26,7 +21,7 @@ from trytond.model import (
     DeactivableMixin, Index, ModelSQL, ModelView, Unique, Workflow, fields)
 from trytond.pool import Pool
 from trytond.pyson import Eval
-from trytond.report import Report, get_email
+from trytond.report import Report, get_email, html_to_text
 from trytond.sendmail import SMTPDataManager, send_message_transactional
 from trytond.tools import grouped_slice, reduce_ids
 from trytond.tools.email_ import (
@@ -506,9 +501,7 @@ class Message(Workflow, ModelSQL, ModelView):
                 msg['List-Unsubscribe'] = (
                     f'<{email.get_email_unsubscribe_url()}>')
                 msg['List-Unsubscribe-Post'] = 'List-Unsubscribe=One-Click'
-                if html2text:
-                    converter = html2text.HTML2Text()
-                    content_text = converter.handle(content)
+                if content_text := html_to_text(content):
                     msg.add_alternative(content_text, subtype='plain')
                 if msg.is_multipart():
                     msg.add_alternative(content, subtype='html')

trytond/doc/ref/report.rst

@@ -147,3 +147,10 @@ Email reports must have ``HTML`` as output format.
 
    .. warning::
       It may return the content unconverted if some dependencies are missing.
+
+.. function:: html_to_text(content):
+
+   Converts ``HTML`` content to plain text.
+
+   .. warning::
+      It may return ``None`` if some dependencies are missing.

trytond/trytond/ir/email_.py

@@ -6,10 +6,6 @@ import re
 from email.message import EmailMessage
 from email.utils import getaddresses
 
-try:
-    import html2text
-except ImportError:
-    html2text = None
 from genshi.template import TextTemplate
 
 import trytond.config as config
@@ -18,7 +14,7 @@ from trytond.model import EvalEnvironment, ModelSQL, ModelView, fields
 from trytond.model.exceptions import AccessError, ValidationError
 from trytond.pool import Pool
 from trytond.pyson import Bool, Eval, PYSONDecoder
-from trytond.report import Report
+from trytond.report import Report, html_to_text
 from trytond.rpc import RPC
 from trytond.sendmail import send_message_transactional
 from trytond.tools import escape_wildcard, slugify
@@ -107,16 +103,14 @@ class Email(ResourceAccessMixin, ModelSQL, ModelView):
             'body': body,
             'signature': user.signature or '',
             }
-        if html2text:
-            body_text = HTML_EMAIL % {
-                'subject': subject,
-                'body': body,
-                'signature': '',
-                }
-            converter = html2text.HTML2Text()
-            body_text = converter.handle(body_text)
+        body_text = HTML_EMAIL % {
+            'subject': subject,
+            'body': body,
+            'signature': '',
+            }
+        if body_text := html_to_text(body_text):
             if user.signature:
-                body_text += '\n-- \n' + converter.handle(user.signature)
+                body_text += '\n-- \n' + html_to_text(user.signature)
             msg.add_alternative(body_text, subtype='plain')
         if msg.is_multipart():
             msg.add_alternative(body_html, subtype='html')

trytond/trytond/report/__init__.py

@@ -1,5 +1,5 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
-from .report import Report, get_email, mjml_to_html
+from .report import Report, get_email, html_to_text, mjml_to_html
 
-__all__ = [Report, get_email, mjml_to_html]
+__all__ = [Report, get_email, html_to_text, mjml_to_html]

trytond/trytond/report/report.py

@@ -21,17 +21,6 @@ from io import BytesIO
 from itertools import groupby
 
 import dateutil.tz
-
-try:
-    import html2text
-except ImportError:
-    html2text = None
-
-try:
-    import weasyprint
-except ImportError:
-    weasyprint = None
-
 from genshi.filters import Translator
 from genshi.template.text import TextTemplate
 
@@ -422,10 +411,10 @@ class Report(URLMixin, PoolBase):
         input_format = report.template_extension
         output_format = report.extension or report.template_extension
 
-        if (weasyprint
-                and input_format in {'html', 'xhtml'}
+        if (input_format in {'html', 'xhtml'}
                 and output_format == 'pdf'):
-            return output_format, weasyprint.HTML(string=data).write_pdf()
+            if weasyprint := _lazy_import('weasyprint'):
+                return output_format, weasyprint.HTML(string=data).write_pdf()
 
         if (input_format == 'xml'
                 and output_format == 'html'
@@ -612,7 +601,6 @@ def get_email(report, record, languages):
         else:
             report_name = report
         Report_ = pool.get(report_name, type='report')
-    converter = None
     title = None
     msg = EmailMessage()
     header_factory = msg.policy.header_factory
@@ -631,13 +619,11 @@ def get_email(report, record, languages):
                 break
         else:
             maintype, subtype = 'application', ext
-        if maintype == 'text' and subtype == 'html' and html2text:
-            if not converter:
-                converter = html2text.HTML2Text()
-            content_text = converter.handle(content)
-            msg.add_alternative(content_text, subtype='plain', headers=[
-                    header_factory('Content-Language', language.code),
-                    ])
+        if maintype == 'text' and subtype == 'html':
+            if content_text := html_to_text(content):
+                msg.add_alternative(content_text, subtype='plain', headers=[
+                        header_factory('Content-Language', language.code),
+                        ])
         types = {
             'subtype': subtype,
             }
@@ -663,3 +649,8 @@ def mjml_to_html(content):
     if mrml := _lazy_import('mrml'):
         content = mrml.to_html(content).content
     return content
+
+
+def html_to_text(content):
+    if html2text := _lazy_import('html2text'):
+        return html2text.HTML2Text().handle(content)

trytond/trytond/tests/test_report.py

@@ -136,9 +136,9 @@ class ReportTestCase(TestCase):
             '<!doctype html><title>Test</title>')
 
     @with_transaction()
-    @patch('trytond.report.report.html2text')
-    def test_get_email_html_without_html2text(self, html2text):
-        html2text.__bool__.side_effect = lambda: False
+    @patch('trytond.report.report.html_to_text')
+    def test_get_email_html_without_html2text(self, html_to_text):
+        html_to_text.side_effect = lambda content: None
 
         class FakeReport(Report):
             @classmethod