From afe00a261b9007b9d82e07ece180ab9e96d4237a Mon Sep 17 00:00:00 2001
From: Konstantin Nosov <konstantin.nosov@gmail.com>
Date: Fri, 4 Oct 2024 12:56:08 +0300
Subject: [PATCH] BlogPlugin: handling of generated blog posts

---
 material/plugins/blog/structure/__init__.py | 72 +++++++++++----------
 1 file changed, 39 insertions(+), 33 deletions(-)

diff --git a/material/plugins/blog/structure/__init__.py b/material/plugins/blog/structure/__init__.py
index 0285f3a9bcb..17f57728678 100644
--- a/material/plugins/blog/structure/__init__.py
+++ b/material/plugins/blog/structure/__init__.py
@@ -40,6 +40,7 @@
 from .config import PostConfig
 from .markdown import ExcerptTreeprocessor
 
+
 # -----------------------------------------------------------------------------
 # Classes
 # -----------------------------------------------------------------------------
@@ -52,40 +53,45 @@ class Post(Page):
     def __init__(self, file: File, config: MkDocsConfig):
         super().__init__(None, file, config)
 
-        # Resolve path relative to docs directory
-        docs = os.path.relpath(config.docs_dir)
-        path = os.path.relpath(file.abs_src_path, docs)
+        if file.generated_by is None:
+            # Resolve path relative to docs directory
+            docs = os.path.relpath(config.docs_dir)
+            path = os.path.relpath(file.abs_src_path, docs)
+            file_origin = f" in '{docs}'"
+        else:
+            # Path for generated posts
+            path = file.src_path
+            file_origin = f" generated by '{file.generated_by}'"
 
         # Read contents and metadata immediately
-        with open(file.abs_src_path, encoding = "utf-8-sig") as f:
-            self.markdown = f.read()
-
-            # Sadly, MkDocs swallows any exceptions that occur during parsing.
-            # Since we want to provide the best possible user experience, we
-            # need to catch errors early and display them nicely. We decided to
-            # drop support for MkDocs' MultiMarkdown syntax, because it is not
-            # correctly implemented anyway. When using MultiMarkdown syntax, all
-            # date formats are returned as strings and list are not properly
-            # supported. Thus, we just use the relevants parts of `get_data`.
-            match: Match = YAML_RE.match(self.markdown)
-            if not match:
-                raise PluginError(
-                    f"Error reading metadata of post '{path}' in '{docs}':\n"
-                    f"Expected metadata to be defined but found nothing"
-                )
-
-            # Extract metadata and parse as YAML
-            try:
-                self.meta = yaml.load(match.group(1), SafeLoader) or {}
-                self.markdown = self.markdown[match.end():].lstrip("\n")
-
-            # The post's metadata could not be parsed because of a syntax error,
-            # which we display to the author with a nice error message
-            except Exception as e:
-                raise PluginError(
-                    f"Error reading metadata of post '{path}' in '{docs}':\n"
-                    f"{e}"
-                )
+        self.markdown = file.content_string
+
+        # Sadly, MkDocs swallows any exceptions that occur during parsing.
+        # Since we want to provide the best possible user experience, we
+        # need to catch errors early and display them nicely. We decided to
+        # drop support for MkDocs' MultiMarkdown syntax, because it is not
+        # correctly implemented anyway. When using MultiMarkdown syntax, all
+        # date formats are returned as strings and list are not properly
+        # supported. Thus, we just use the relevants parts of `get_data`.
+        match: Match = YAML_RE.match(self.markdown)
+        if not match:
+            raise PluginError(
+                f"Error reading metadata of post '{path}' {file_origin}:\n"
+                f"Expected metadata to be defined but found nothing"
+            )
+
+        # Extract metadata and parse as YAML
+        try:
+            self.meta = yaml.load(match.group(1), SafeLoader) or {}
+            self.markdown = self.markdown[match.end():].lstrip("\n")
+
+        # The post's metadata could not be parsed because of a syntax error,
+        # which we display to the author with a nice error message
+        except Exception as e:
+            raise PluginError(
+                f"Error reading metadata of post '{path}' {file_origin}:\n"
+                f"{e}"
+            )
 
         # Initialize post configuration, but remove all keys that this plugin
         # doesn't care about, or they will be reported as invalid configuration
@@ -103,7 +109,7 @@ def __init__(self, file: File, config: MkDocsConfig):
             log.warning(w)
         for k, e in errors:
             raise PluginError(
-                f"Error reading metadata '{k}' of post '{path}' in '{docs}':\n"
+                f"Error reading metadata '{k}' of post '{path}' {file_origin}:\n"
                 f"{e}"
             )