fix: pagging handling in case of missing page and skip for SVG based diagrams (#40)

Signed-off-by: Jan Larwig <jan@larwig.com>

Author: tuunit

examples/docs/tests/pagging/index.md

@@ -34,7 +34,7 @@ markdown_extensions:
 ---
 
 === "Diagram"
-    Below you should see diagram Page-2 using the attribute page:
+    Below you should see the diagram Page-2 using the page attribute:
     ![Some alt text](test.drawio){ page="Page-2" }
 
 === "Markdown"
@@ -45,17 +45,47 @@ markdown_extensions:
 ---
 
 === "Diagram"
-    Below you should see Page-1 (default) because the specified Page-3 has not been found:
+    If the alt text doesn't exist as a page it will fallback to the first page of your diagram.
+    Below you should therefore see Page-1 (default):
     ![Page-3](test.drawio)
-    
+
     Furthoremore, you should see a warning in your mkdocs server similar to:
-    
+
     ```bash
     WARNING -  Warning: Found 0 results for page name 'Page-3' for diagram 'test.drawio' on path '/tmp/mkdocs_ce1qjhyn/test2'
     ```
 
 === "Markdown"
     ```markdown
-    If page doesn't exist it will fallback to the first page.
     ![Page-3](test.drawio)
     ```
+
+---
+
+=== "Diagram"
+    If the alt text and page attribute don't exist as a page, it will fallback to the first page of your diagram.
+    Below you should therefore see Page-1 (default):
+    ![Some alt text](test.drawio){ page="Page-3" }
+
+    Furthoremore, you should see a warning in your mkdocs server similar to:
+
+    ```bash
+    WARNING -  Warning: Found 0 results for page name 'Page-3' for diagram 'test.drawio' on path '/tmp/mkdocs_ce1qjhyn/test2'
+    ```
+
+=== "Markdown"
+    ```markdown
+    ![Some alt text](test.drawio){ page="Page-3" }
+    ```
+
+---
+
+=== "Diagram"
+    Pagging logic for SVG diagrams is skip as only a single page can be exported as an SVG drawio diagram.
+
+    ![Some alt text](test.drawio.svg){ page="Page-3" }
+
+=== "Markdown"
+    ```markdown
+    ![Some alt text](test.drawio.svg){ page="Page-3" }
+    ```

examples/docs/tests/pagging/test.drawio.svg

@@ -2,14 +2,17 @@
 
 ## Example
 
+=== "Diagram"
+
 The following is a SVG based drawio diagram:
 
 ![](test.drawio.svg)
 
 You can open the diagram as an SVG in your browser. [Click here.](test.drawio.svg)
 
-## Markdown
+=== "Markdown"
 
 ```markdown
 ![](test.drawio.svg)
 ```
+

examples/docs/tests/svg/index.md

@@ -74,10 +74,14 @@ def render_drawio_diagrams(self, output_content, page):
                     "html.parser",
                 )
             else:
-                diagram_page = diagram["alt"]
+                diagram_page = ""
+
                 # Use page attribute instead of alt if it is set
-                if "page" in diagram:
-                    diagram_page = diagram["page"]
+                if diagram.has_attr("page"):
+                    diagram_page = diagram.get("page")
+                else:
+                    diagram_page = diagram.get("alt")
+
                 mxgraph = BeautifulSoup(
                     DrawioPlugin.substitute_with_file(
                         diagram_config, path, diagram["src"], diagram_page
@@ -96,48 +100,46 @@ def substitute_with_url(config: Dict, url: str) -> str:
         return SUB_TEMPLATE.substitute(config=escape(json.dumps(config)))
 
     @staticmethod
-    def substitute_with_file(config: Dict, path: Path, src: str, alt: str) -> str:
+    def substitute_with_file(config: Dict, path: Path, src: str, page: str) -> str:
         try:
             diagram_xml = etree.parse(path.joinpath(src).resolve())
-        except Exception:
+        except Exception as e:
             LOGGER.error(
-                f"Error: Provided diagram file '{src}' on path '{path}' is not a valid diagram"
+                f"Error: Could not parse diagram file '{src}' on path '{path}': {e}"
             )
-            diagram_xml = etree.fromstring("<invalid/>")
+            config["xml"] = ""
+            return SUB_TEMPLATE.substitute(config=escape(json.dumps(config)))
 
-        diagram = DrawioPlugin.parse_diagram(diagram_xml, alt)
+        diagram = DrawioPlugin.parse_diagram(diagram_xml, page)
         config["xml"] = diagram
-
         return SUB_TEMPLATE.substitute(config=escape(json.dumps(config)))
 
     @staticmethod
-    def parse_diagram(data, alt, src="", path=None) -> str:
-        if alt is None or len(alt) == 0:
-            return etree.tostring(data, encoding=str)
+    def parse_diagram(data, page_name, src="", path=None) -> str:
+        mxfile_nodes = data.xpath("//mxfile")
 
-        try:
-            mxfile = data.xpath("//mxfile")[0]
+        if not mxfile_nodes:
+            if data.xpath("//*[local-name()='svg']") is not None:
+                return etree.tostring(data, encoding=str)
+            return ""
 
-            # try to parse for a specific page by using the alt attribute
-            page = mxfile.xpath(f"//diagram[@name='{alt}']")
+        mxfile = mxfile_nodes[0]
 
-            if len(page) == 1:
-                parser = etree.XMLParser()
-                result = parser.makeelement(mxfile.tag, mxfile.attrib)
+        if not page_name:
+            return etree.tostring(mxfile, encoding=str)
 
-                result.append(page[0])
-                return etree.tostring(result, encoding=str)
-            else:
-                LOGGER.warning(
-                    f"Warning: Found {len(page)} results for page name '{alt}' for diagram '{src}' on path '{path}'"
-                )
+        page = mxfile.xpath(f"//diagram[@name='{page_name}']")
+        if len(page) == 1:
+            parser = etree.XMLParser()
+            result = parser.makeelement(mxfile.tag, mxfile.attrib)
+            result.append(page[0])
+            return etree.tostring(result, encoding=str)
 
-            return etree.tostring(mxfile, encoding=str)
-        except Exception:
-            LOGGER.error(
-                f"Error: Could not properly parse page name '{alt}' for diagram '{src}' on path '{path}'"
-            )
-        return ""
+        LOGGER.warning(
+            f"Warning: Found {len(page)} results for page name '{page_name}' "
+            f"falling back to first page."
+        )
+        return etree.tostring(mxfile, encoding=str)
 
     def on_config(self, config: base.Config):
         """Load embedded files"""

mkdocs_drawio/plugin.py

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "mkdocs-drawio"
-version = "1.11.2"
+version = "1.11.3"
 description = "MkDocs plugin for embedding Drawio files"
 authors = [
     "Jan Larwig <jan@larwig.com>",