Merge pull request #40 from moggers87/16-tree-walkies

Implement Node.get_from_path

CHANGELOG.rst

@@ -9,6 +9,8 @@ Unreleased
 - Improved test coverage and fixed numerous bugs
 - Implemented cache busting for static assets (images, CSS, and such). Use the
   ``cache-bust-glob`` option to control which files are cache busted.
+- Implemented ``Node.get_from_path`` which can fetch a
+  :class:`exhibition.main.Node` specified by a path
 
 .. _zero-zero-three:
 

exhibition/main.py

@@ -208,6 +208,9 @@ def __init__(self, path, parent, meta=None):
 
         if self.parent:
             self.parent.add_child(self)
+            self.root_node = self.parent.root_node
+        else:
+            self.root_node = self
 
     @classmethod
     def from_path(cls, path, parent=None, meta=None):
@@ -255,6 +258,38 @@ def from_path(cls, path, parent=None, meta=None):
     def __repr__(self):
         return "<%s: %s>" % (self.__class__.__name__, self.path_obj.name)
 
+    def get_from_path(self, path):
+        """
+        Given a relative or absolute path, return the :class:`Node` that
+        represents that path.
+
+        :param path:
+            A :class:`str` or :class:`pathlib.Path`
+        """
+        if not isinstance(path, pathlib.PurePath):
+            path = pathlib.PurePath(path)
+
+        if path.is_absolute():
+            found_node = self.root_node
+            parts = path.parts[1:]
+        else:
+            if self.is_leaf:
+                found_node = self.parent
+            else:
+                found_node = self
+            parts = path.parts
+
+        try:
+            for part in parts:
+                if part == "..":
+                    found_node = found_node.parent
+                else:
+                    found_node = found_node.children[part]
+        except KeyError as exp:
+            raise OSError("{} could not find {}".format(self, exp.args)) from exp
+
+        return found_node
+
     @property
     def full_path(self):
         """

exhibition/tests/test_node.py

@@ -490,3 +490,189 @@ def test_cache_bust_text_file(self):
                                           "bust-me.{}.jpg".format(JSON_DIGEST))))
 
         self.assertEqual(child_node.full_url, "/bust-me.{}.jpg".format(JSON_DIGEST))
+
+    def test_get_from_path_relative_str_on_leaf(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["images"].children["bust-me.jpg"]
+        target_node = parent_node.children["pages"].children["page.html"]
+
+        self.assertEqual(child_node.get_from_path("../pages/page.html"), target_node)
+
+    def test_get_from_path_relative_pathlib_on_leaf(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["images"].children["bust-me.jpg"]
+        target_node = parent_node.children["pages"].children["page.html"]
+
+        self.assertEqual(child_node.get_from_path(pathlib.Path("..", "pages", "page.html")),
+                         target_node)
+
+    def test_get_from_path_relative_str_on_dir(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["images"]
+        target_node = parent_node.children["pages"].children["page.html"]
+
+        self.assertEqual(child_node.get_from_path("../pages/page.html"), target_node)
+
+    def test_get_from_path_relative_pathlib_on_dir(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["images"]
+        target_node = parent_node.children["pages"].children["page.html"]
+
+        self.assertEqual(child_node.get_from_path(pathlib.Path("..", "pages", "page.html")),
+                         target_node)
+
+    def test_get_from_path_relative_str_with_dot(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["pages"]
+        target_node = parent_node.children["pages"].children["page.html"]
+
+        self.assertEqual(child_node.get_from_path("./page.html"), target_node)
+
+    def test_get_from_path_relative_pathlib_with_dot(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["pages"]
+        target_node = parent_node.children["pages"].children["page.html"]
+
+        self.assertEqual(child_node.get_from_path(pathlib.Path(".", "page.html")),
+                         target_node)
+
+    def test_get_from_path_absolute_str(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["images"].children["bust-me.jpg"]
+        target_node = parent_node.children["pages"].children["page.html"]
+
+        self.assertEqual(child_node.get_from_path("/pages/page.html"), target_node)
+
+    def test_get_from_path_absolute_pathlib(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["images"].children["bust-me.jpg"]
+        target_node = parent_node.children["pages"].children["page.html"]
+
+        self.assertEqual(child_node.get_from_path(pathlib.Path("/pages/page.html")), target_node)
+
+    def test_get_from_path_not_existing_from_str(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["images"].children["bust-me.jpg"]
+
+        with self.assertRaises(OSError):
+            child_node.get_from_path("../not-a-page.html")
+
+    def test_get_from_path_not_existing_from_pathlib(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        child1_path = pathlib.Path(self.content_path.name, "images", "bust-me.jpg")
+        child1_path.touch()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child2_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child2_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        child_node = parent_node.children["images"].children["bust-me.jpg"]
+
+        with self.assertRaises(OSError):
+            child_node.get_from_path(pathlib.Path("..", "not-a-page.html"))
+
+    def test_root_node_is_kept(self):
+        parent_path = pathlib.Path(self.content_path.name)
+        pathlib.Path(self.content_path.name, "images").mkdir()
+        pathlib.Path(self.content_path.name, "pages").mkdir()
+        child_path = pathlib.Path(self.content_path.name, "pages", "page.html")
+        child_path.touch()
+
+        parent_node = Node.from_path(parent_path)
+
+        self.assertEqual(parent_node.root_node, parent_node)
+        self.assertEqual(parent_node.children["pages"].root_node, parent_node)
+        self.assertEqual(parent_node.children["pages"].children["page.html"].root_node, parent_node)
+        self.assertEqual(parent_node.children["pages"].children["page.html"].parent.root_node,
+                         parent_node)
+        self.assertEqual(
+            parent_node.children["pages"].children["page.html"].parent.parent.root_node,
+            parent_node
+        )
+        self.assertEqual(
+            parent_node.children["pages"].children["page.html"].parent.parent.root_node,
+            parent_node
+        )