Pi66

merodi
A markdown-based static site generator.
git clone https://git.pi66.xyz/merodi

← back to log

hooks: multi-subscriber system with priority and error isolation

author: pi66
date: 2026-07-21 10:13
hash: 597fb7b3fd5f14273e8d3368ae3040990a1888cf

Diffstat:

M

src/hooks.py
102 ++++++++++++++++++------------
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
diff --git a/src/hooks.py b/src/hooks.py
index 085eb2e..7700d33 100644
--- a/src/hooks.py
+++ b/src/hooks.py
@@ -1,49 +1,67 @@
 from .log import GRAY, warn

+DEFAULT_PRIORITY = 100
+
 hooks = {
-    "on_build_end"              : None,
-    "on_build_start"            : None,
-    "on_config_load"            : None,
-    "on_file_changed"           : None,
-    "on_hash_check"             : None,
-    "on_hash_written"           : None,
-    "on_highlight_config"       : None,
-    "on_html_filter"            : None,
-    "on_jinja_error"            : None,
-    "on_jinja_template_dir"     : None,
-    "on_jinja_template_renderer": None,
-    "on_math_renderer"          : None,
-    "on_md_to_html"             : None,
-    "on_page_read"              : None,
-    "on_page_rendered"          : None,
-    "on_page_skip"              : None,
-    "on_page_written"           : None,
-    "on_plugins_before_export"  : None,
-    "on_plugins_loaded"         : None,
-    "on_reload_error"           : None,
-    "on_walk_end"               : None,
-    "on_walk_file"              : None,
-    "on_walk_start"             : None,
-    "on_watch_start"            : None,
-    "on_watch_stop"             : None,
+    "on_build_end"              : [],
+    "on_build_start"            : [],
+    "on_compile_start"          : [],
+    "on_config_load"            : [],
+    "on_end"                    : [],
+    "on_file_changed"           : [],
+    "on_hash_check"             : [],
+    "on_hash_written"           : [],
+    "on_highlight_config"       : [],
+    "on_html_filter"            : [],
+    "on_jinja_error"            : [],
+    "on_jinja_template_dir"     : [],
+    "on_jinja_template_renderer": [],
+    "on_math_renderer"          : [],
+    "on_md_to_html"             : [],
+    "on_page_built"             : [],
+    "on_page_read"              : [],
+    "on_page_rendered"          : [],
+    "on_page_skip"              : [],
+    "on_page_written"           : [],
+    "on_plugin_changed"         : [],
+    "on_plugins_before_export"  : [],
+    "on_plugins_loaded"         : [],
+    "on_reload_error"           : [],
+    "on_start"                  : [],
+    "on_walk_end"               : [],
+    "on_walk_file"              : [],
+    "on_walk_start"             : [],
+    "on_watch_start"            : [],
+    "on_watch_stop"             : [],
 }
-                             
-def hook(hook_name:str):
-    if hook_name in hooks:
-        def hook_fn(fn):
-            if not hooks.get(hook_name) == None:
-                warn(f"Overwriting existing hook '{hook_name}'.")
-            hooks[hook_name]=fn
-            return fn
-        return hook_fn

-    else:
-        warn(f"Skipping hook `{GRAY(hook_name)}`: hook is not exists")
-        return lambda fn:fn
+def hook(hook_name: str, priority: int = DEFAULT_PRIORITY):
+    if hook_name not in hooks:
+        warn(f"Skipping hook `{GRAY(hook_name)}`: hook does not exist")
+        return lambda fn: fn
+
+    def hook_fn(fn):
+        hooks[hook_name].append((priority, fn))
+        hooks[hook_name].sort(key=lambda x: x[0])
+        return fn
+    return hook_fn

 def hook_call(hook_name, *args, **kwargs):
-    if hook_name not in  hooks:
-        warn(hook_name)
-    func = hooks.get(hook_name)
-    if callable(func):
-        return func(*args, **kwargs)
+    subscribers = hooks.get(hook_name, [])
+    if not subscribers:
+        return None
+    result = None
+    for _priority, fn in subscribers:
+        try:
+            result = fn(*args, **kwargs)
+        except Exception as e:
+            warn(f"Hook '{hook_name}' failed in {fn.__name__}: {e}")
+    return result
+
+def reset_hooks():
+    for key in hooks:
+        hooks[key] = []
+
+def remove_hook(hook_name, fn):
+    if hook_name in hooks:
+        hooks[hook_name] = [(p, f) for p, f in hooks[hook_name] if f is not fn]