From ba6bdf35be1d35ca3a7f57e6066c92eb228f6fc7 Mon Sep 17 00:00:00 2001
From: Richard Hansen <rhansen@rhansen.org>
Date: Tue, 6 Oct 2020 17:47:03 -0400
Subject: [PATCH] Make the aceAttribClasses hook harder to misuse

---
 doc/api/hooks_server-side.md     | 17 ++++++++++-------
 src/static/js/linestylefilter.js |  5 +++--
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/doc/api/hooks_server-side.md b/doc/api/hooks_server-side.md
index 57ae1c117..9c8630b4d 100644
--- a/doc/api/hooks_server-side.md
+++ b/doc/api/hooks_server-side.md
@@ -679,18 +679,21 @@ exports.stylesForExport = function(hook, padId, cb){
 ## aceAttribClasses
 Called from: src/static/js/linestylefilter.js
 
-Things in context:
-1. Attributes - Object of Attributes
+This hook is called when attributes are investigated on a line. It is useful if
+you want to add another attribute type or property type to a pad.
 
-This hook is called when attributes are investigated on a line.  It is useful if you want to add another attribute type or property type to a pad.
+An attributes object is passed to the aceAttribClasses hook functions instead of
+the usual context object. A hook function can either modify this object directly
+or provide an object whose properties will be assigned to the attributes object.
 
 Example:
 
 ```
-exports.aceAttribClasses = function(hook_name, attr, cb){
-  attr.sub = 'tag:sub';
-  cb(attr);
-}
+exports.aceAttribClasses = (hookName, attrs, cb) => {
+  return cb([{
+    sub: 'tag:sub',
+  }]);
+};
 ```
 
 ## exportFileName
diff --git a/src/static/js/linestylefilter.js b/src/static/js/linestylefilter.js
index a3cf68433..b3496a818 100644
--- a/src/static/js/linestylefilter.js
+++ b/src/static/js/linestylefilter.js
@@ -59,8 +59,9 @@ linestylefilter.getLineStyleFilter = function(lineLength, aline, textAndClassFun
 {
 
   // Plugin Hook to add more Attrib Classes
-  const results = hooks.callAll('aceAttribClasses', linestylefilter.ATTRIB_CLASSES);
-  if (results.length >= 1) linestylefilter.ATTRIB_CLASSES = results[0];
+  for (const attribClasses of hooks.callAll('aceAttribClasses', linestylefilter.ATTRIB_CLASSES)) {
+    Object.assign(linestylefilter.ATTRIB_CLASSES, attribClasses);
+  }
 
   if (lineLength == 0) return textAndClassFunc;