Deduplicate campaign template rendering

src/govoplan_campaign/backend/attachments/resolver.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import fnmatch
-import re
 import time
 from dataclasses import dataclass, field
 from enum import StrEnum
@@ -18,6 +17,7 @@ from govoplan_campaign.backend.path_security import (
     assert_logical_relative_path,
     is_managed_source,
 )
+from govoplan_campaign.backend.template_rendering import render_template
 
 
 class AttachmentScope(StrEnum):
@@ -145,43 +145,8 @@ def _resolve_path(campaign_file: str | Path, raw_path: str) -> Path:
     return (campaign_path.parent / path).resolve()
 
 
-_DOLLAR_FIELD_PATTERN = re.compile(r"(?<!\\)\$\{(.*?)(?<!\\)\}")
-_BRACE_FIELD_PATTERN = re.compile(r"(?<!\\)\{\{\s*(.*?)\s*\}\}")
-
-
-def _normalize_template_key(raw: str) -> str:
-    key = raw.strip()
-    if key.startswith("fields."):
-        key = key.removeprefix("fields.")
-    elif key.startswith("local."):
-        key = "local::" + key.removeprefix("local.")
-    elif key.startswith("global."):
-        key = "global::" + key.removeprefix("global.")
-
-    if key.startswith("local::") or key.startswith("global::"):
-        return key
-    if key.startswith("local:"):
-        return "local::" + key.removeprefix("local:")
-    if key.startswith("global:"):
-        return "global::" + key.removeprefix("global:")
-    return key
-
-
-def _render_template(template: str, values: dict[str, Any]) -> str:
-    def replace(match: re.Match[str]) -> str:
-        key = _normalize_template_key(match.group(1))
-        if key in values:
-            value = values[key]
-            return "" if value is None else str(value)
-        return match.group(0)
-
-    rendered = _DOLLAR_FIELD_PATTERN.sub(replace, template)
-    rendered = _BRACE_FIELD_PATTERN.sub(replace, rendered)
-    return rendered.replace(r"\${", "${").replace(r"\}", "}")
-
-
 def _rendered_base_dir(config: AttachmentConfig, values: dict[str, Any]) -> str:
-    rendered = _render_template(config.base_dir, values).strip()
+    rendered = render_template(config.base_dir, values, keep_missing=True).strip()
     return rendered or "."
 
 
@@ -265,7 +230,7 @@ def _attachment_zip_archive(
 def _render_zip_filename(archive: ZipArchiveConfig | None, values: dict[str, Any]) -> str | None:
     if archive is None:
         return None
-    rendered = _render_template(archive.name or "attachments.zip", values).strip() or "attachments.zip"
+    rendered = render_template(archive.name or "attachments.zip", values, keep_missing=True).strip() or "attachments.zip"
     return rendered if rendered.lower().endswith(".zip") else f"{rendered}.zip"
 
 
@@ -444,7 +409,7 @@ def _resolve_one_config(
     match_index: AttachmentMatchIndex | None = None,
 ) -> ResolvedAttachment:
     rendered_base_dir = _rendered_base_dir(config, values)
-    rendered_file_filter = _render_template(config.file_filter, values)
+    rendered_file_filter = render_template(config.file_filter, values, keep_missing=True)
     directory, selected_base_path = _resolve_attachment_directory(
         campaign_file=campaign_file,
         campaign_config=campaign_config,

src/govoplan_campaign/backend/messages/builder.py

@@ -36,6 +36,10 @@ from govoplan_campaign.backend.campaign.models import (
 )
 from govoplan_campaign.backend.campaign.template_values import build_template_values
 from govoplan_campaign.backend.services.zip_service import create_zip_archive
+from govoplan_campaign.backend.template_rendering import (
+    find_unresolved_placeholders as _find_unresolved_placeholders,
+    render_template as _render_template,
+)
 
 from .models import (
     CampaignBuildReport,
@@ -47,28 +51,6 @@ from .models import (
     MessageValidationStatus,
 )
 
-_DOLLAR_FIELD_PATTERN = re.compile(r"(?<!\\)\$\{(.*?)(?<!\\)\}")
-_BRACE_FIELD_PATTERN = re.compile(r"(?<!\\)\{\{\s*(.*?)\s*\}\}")
-
-
-def _normalize_template_key(raw: str) -> str:
-    key = raw.strip()
-    if key.startswith("fields."):
-        key = key.removeprefix("fields.")
-    elif key.startswith("local."):
-        key = "local::" + key.removeprefix("local.")
-    elif key.startswith("global."):
-        key = "global::" + key.removeprefix("global.")
-
-    if key.startswith("local::") or key.startswith("global::"):
-        return key
-    if key.startswith("local:"):
-        return "local::" + key.removeprefix("local:")
-    if key.startswith("global:"):
-        return "global::" + key.removeprefix("global:")
-    return key
-
-
 @dataclass(slots=True)
 class BuiltMessage:
     draft: MessageDraft
@@ -123,29 +105,6 @@ def _read_text(campaign_file: str | Path, raw_path: str | None, encoding: str =
     return path.read_text(encoding=encoding)
 
 
-def _render_template(template: str, values: dict[str, Any], *, keep_missing: bool = True) -> str:
-    def replace(match: re.Match[str]) -> str:
-        key = _normalize_template_key(match.group(1))
-        if key in values:
-            value = values[key]
-            return "" if value is None else str(value)
-        return match.group(0) if keep_missing else ""
-
-    rendered = _DOLLAR_FIELD_PATTERN.sub(replace, template)
-    rendered = _BRACE_FIELD_PATTERN.sub(replace, rendered)
-    return rendered.replace(r"\${", "${").replace(r"\}", "}")
-
-
-def _find_unresolved_placeholders(text: str | None) -> set[str]:
-    if not text:
-        return set()
-    return {
-        _normalize_template_key(match.group(1))
-        for pattern in (_DOLLAR_FIELD_PATTERN, _BRACE_FIELD_PATTERN)
-        for match in pattern.finditer(text)
-    }
-
-
 def _message_address(recipient: RecipientConfig | None) -> MessageAddress | None:
     if recipient is None:
         return None

src/govoplan_campaign/backend/template_rendering.py

@@ -0,0 +1,55 @@
+from __future__ import annotations
+
+import re
+from collections.abc import Mapping
+from typing import Any
+
+
+_DOLLAR_FIELD_PATTERN = re.compile(r"(?<!\\)\$\{(.*?)(?<!\\)\}")
+_BRACE_FIELD_PATTERN = re.compile(r"(?<!\\)\{\{\s*(.*?)\s*\}\}")
+
+
+def normalize_template_key(raw: str) -> str:
+    key = raw.strip()
+    if key.startswith("fields."):
+        key = key.removeprefix("fields.")
+    elif key.startswith("local."):
+        key = "local::" + key.removeprefix("local.")
+    elif key.startswith("global."):
+        key = "global::" + key.removeprefix("global.")
+
+    if key.startswith("local::") or key.startswith("global::"):
+        return key
+    if key.startswith("local:"):
+        return "local::" + key.removeprefix("local:")
+    if key.startswith("global:"):
+        return "global::" + key.removeprefix("global:")
+    return key
+
+
+def render_template(
+    template: str,
+    values: Mapping[str, Any],
+    *,
+    keep_missing: bool = True,
+) -> str:
+    def replace(match: re.Match[str]) -> str:
+        key = normalize_template_key(match.group(1))
+        if key in values:
+            value = values[key]
+            return "" if value is None else str(value)
+        return match.group(0) if keep_missing else ""
+
+    rendered = _DOLLAR_FIELD_PATTERN.sub(replace, template)
+    rendered = _BRACE_FIELD_PATTERN.sub(replace, rendered)
+    return rendered.replace(r"\${", "${").replace(r"\}", "}")
+
+
+def find_unresolved_placeholders(text: str | None) -> set[str]:
+    if not text:
+        return set()
+    return {
+        normalize_template_key(match.group(1))
+        for pattern in (_DOLLAR_FIELD_PATTERN, _BRACE_FIELD_PATTERN)
+        for match in pattern.finditer(text)
+    }