[FIX] website_slides: prevent constraint error when changing the type

Before this commit
==================
Modifying the type of content from video to webpage or webpage to video
violates the constraint.

Technical
=========
When we change the 'slide_type' of the slide.slide model from video to any
other type, or from webpage to any other type, the value url or html_content
is not removed and remains same. However, when switching between video and
webpage, the 'exclusion_html_content_and_url' constraint is violated because one
of them should be null.

After this commit
=================
When the type of content is changed, the existing URL or HTML content is
removed as they are no longer needed.

Task-3474466

closes odoo/odoo#144042

X-original-commit: b68d2f52e9d3d0f18257a17dc1a24db6bee860b1
Signed-off-by: Stéphane Debauche (std) <std@odoo.com>

addons/website_slides/models/slide_slide.py

@@ -667,6 +667,15 @@ class Slide(models.Model):
             values['is_preview'] = True
             values['is_published'] = True
 
+        # if the slide type is changed, remove incompatible url or html_content
+        # done here to satisfy the SQL constraint
+        # using a stored-computed field in place does not work
+        if 'slide_category' in values:
+            if values['slide_category'] == 'article':
+                values = {'url': False, **values}
+            elif values['slide_category'] != 'article':
+                values = {'html_content': False, **values}
+
         res = super(Slide, self).write(values)
         if values.get('is_published'):
             self.date_published = datetime.datetime.now()

addons/website_slides/tests/test_slide_slide.py

@@ -81,6 +81,23 @@ class TestSlideInternals(slides_common.SlidesCase):
             slide.user_has_completed = True
         self.assertTrue(category_slides[0].user_has_completed_category)
 
+    def test_change_content_type(self):
+        """ To prevent constraint violation when changing type from video to article and vice-versa """
+        slide = self.env['slide.slide'].with_context(website_slides_skip_fetch_metadata=True).create({
+            'name': 'dummy',
+            'channel_id': self.channel.id,
+            'slide_category': 'video',
+            'is_published': True,
+            'url': 'https://youtu.be/W0JQcpGLSFw',
+        })
+
+        slide.write({'slide_category': 'article', 'html_content': '<p>Hello</p>'})
+        self.assertTrue(slide.html_content)
+        self.assertFalse(slide.url)
+
+        slide.slide_category = 'document'
+        self.assertFalse(slide.html_content)
+
 class TestVideoFromURL(slides_common.SlidesCase):
     def test_video_youtube(self):
         youtube_urls = {