efficient build

- postpone building until really needed
- rebuild only if artifacts change
- no build on source update
- prune takes current resolver state instead of global var

lektor_groupby/resolver.py

@@ -1,11 +1,11 @@
-from lektor.db import Record
-from lektor.environment import Environment
-from lektor.sourceobj import SourceObject
+from lektor.db import Record  # isinstance
 from lektor.utils import build_url
-
-from typing import Dict, List, Tuple, Optional
-from .config import Config  # typing
-from .vobj import GroupBySource, VPATH
+from typing import TYPE_CHECKING, Dict, List, Tuple, Optional, Iterable
+from .vobj import VPATH, GroupBySource
+if TYPE_CHECKING:
+    from lektor.environment import Environment
+    from lektor.sourceobj import SourceObject
+    from .config import Config
 
 
 class Resolver:
@@ -14,31 +14,18 @@ class Resolver:
     Init will subscribe to @urlresolver and @virtualpathresolver.
     '''
 
-    def __init__(self, env: Environment) -> None:
+    def __init__(self, env: 'Environment') -> None:
         self._data = {}  # type: Dict[str, Tuple[str, Config]]
+        env.urlresolver(self.resolve_server_path)
+        env.virtualpathresolver(VPATH.lstrip('@'))(self.resolve_virtual_path)
 
-        # Local server only: resolve /tag/rss/ -> /tag/rss/index.html
-        @env.urlresolver
-        def dev_server_path(node: SourceObject, pieces: List[str]) \
-                -> Optional[GroupBySource]:
-            if isinstance(node, Record):
-                rv = self._data.get(build_url([node.url_path] + pieces))
-                if rv:
-                    return GroupBySource(node, group=rv[0], config=rv[1])
-            return None
+    @property
+    def has_any(self) -> bool:
+        return bool(self._data)
 
-        # Admin UI only: Prevent server error and null-redirect.
-        @env.virtualpathresolver(VPATH.lstrip('@'))
-        def virtual_path(node: SourceObject, pieces: List[str]) \
-                -> Optional[GroupBySource]:
-            if isinstance(node, Record) and len(pieces) >= 2:
-                path = node['_path']  # type: str
-                key, grp, *_ = pieces
-                for group, conf in self._data.values():
-                    if key == conf.key and path == conf.root:
-                        if conf.slugify(group) == grp:
-                            return GroupBySource(node, group, conf)
-            return None
+    @property
+    def files(self) -> Iterable[str]:
+        return self._data
 
     def reset(self) -> None:
         ''' Clear previously recorded virtual objects. '''
@@ -48,3 +35,28 @@ class Resolver:
         ''' Track new virtual object (only if slug is set). '''
         if vobj.slug:
             self._data[vobj.url_path] = (vobj.group, vobj.config)
+
+    # ------------
+    #   Resolver
+    # ------------
+
+    def resolve_server_path(self, node: 'SourceObject', pieces: List[str]) \
+            -> Optional[GroupBySource]:
+        ''' Local server only: resolve /tag/rss/ -> /tag/rss/index.html '''
+        if isinstance(node, Record):
+            rv = self._data.get(build_url([node.url_path] + pieces))
+            if rv:
+                return GroupBySource(node, group=rv[0], config=rv[1])
+        return None
+
+    def resolve_virtual_path(self, node: 'SourceObject', pieces: List[str]) \
+            -> Optional[GroupBySource]:
+        ''' Admin UI only: Prevent server error and null-redirect. '''
+        if isinstance(node, Record) and len(pieces) >= 2:
+            path = node['_path']  # type: str
+            key, grp, *_ = pieces
+            for group, conf in self._data.values():
+                if key == conf.key and path == conf.root:
+                    if conf.slugify(group) == grp:
+                        return GroupBySource(node, group, conf)
+        return None