fix: remove not thread-safe template compile from parallel loop

and catch exceptions

Author: simontaurus

src/osw/core.py

@@ -16,7 +16,10 @@
 
 import osw.model.entity as model
 from osw.model.static import OswBaseModel
-from osw.utils.templates import eval_handlebars_template
+from osw.utils.templates import (
+    compile_handlebars_template,
+    eval_compiled_handlebars_template,
+)
 from osw.utils.util import parallelize
 from osw.utils.wiki import (
     get_namespace,
@@ -595,6 +598,9 @@ def store_entity(
         meta_category = self.site.get_page(
             WtSite.GetPageParam(titles=[param.meta_category_title])
         ).pages[0]
+        meta_category_template = meta_category.get_slot_content("schema_template")
+        if meta_category_template:
+            meta_category_template = compile_handlebars_template(meta_category_template)
 
         def store_entity_(
             entity: model.Entity, namespace_: str = None, index: int = None
@@ -621,14 +627,19 @@ def store_entity_(
                 "footer", "{{#invoke:Entity|footer}}"
             )  # required for footer rendering
             if namespace_ == "Category":
-                template = meta_category.get_slot_content("schema_template")
-                if template:
-                    schema = json.loads(
-                        eval_handlebars_template(
-                            template, jsondata, {"_page_title": entity_title}
+                if meta_category_template:
+                    try:
+                        schema_str = eval_compiled_handlebars_template(
+                            meta_category_template,
+                            jsondata,
+                            {"_page_title": entity_title},
+                        )
+                        schema = json.loads(schema_str)
+                        page.set_slot_content("jsonschema", schema)
+                    except Exception as e:
+                        print(
+                            f"Schema generation from template failed for {entity}: {e}"
                         )
-                    )
-                    page.set_slot_content("jsonschema", schema)
             page.edit()
             if index is None:
                 print(f"Entity stored at {page.get_url()}.")

src/osw/utils/templates.py

@@ -1,10 +1,56 @@
 from pybars import Compiler
 
 
+def compile_handlebars_template(template):
+    """compiles a handlebars template.
+    WARNING: not thread safe!
+
+    Parameters
+    ----------
+    template
+        the template string
+
+    Returns
+    -------
+        the compiled template
+    """
+    compiler = Compiler()
+    template = compiler.compile(template)
+    return template
+
+
+def eval_compiled_handlebars_template(
+    compiled_template, data, helpers={}, partials={}, add_self_as_partial=True
+):
+    """evaluates a compiled handlebars template with the given data
+
+    Parameters
+    ----------
+    compiled_template
+        the compiled template
+    data
+        the data dictionary
+    helpers, optional
+        helper functions, by default {}
+    partials, optional
+        partials, by default {}
+    add_self_as_partial, optional
+        if true, add the compiled template as partial 'self', by default True
+
+    Returns
+    -------
+        the evaluated template as a string
+    """
+    if add_self_as_partial:
+        partials["self"] = compiled_template
+    return compiled_template(data, helpers=helpers, partials=partials)
+
+
 def eval_handlebars_template(
     template, data, helpers={}, partials={}, add_self_as_partial=True
 ):
-    """evaluates a handlebars template with the given data
+    """evaluates a handlebars template with the given data.
+    WARNING: not thread safe!
 
     Parameters
     ----------
@@ -23,8 +69,11 @@ def eval_handlebars_template(
     -------
         the evaluated template as a string
     """
-    compiler = Compiler()
-    template = compiler.compile(template)
-    if add_self_as_partial:
-        partials["self"] = template
-    return template(data, helpers=helpers, partials=partials)
+    compiled_template = compile_handlebars_template(template)
+    return eval_compiled_handlebars_template(
+        compiled_template,
+        data,
+        helpers,
+        partials,
+        add_self_as_partial,
+    )