Patterns blacklist

README.md

@@ -134,6 +134,18 @@ To facilitate debugging you can change the default log level through the URL que
 - `http://www.example.com/?loglevel-inject=DEBUG` changes the log level for just the inject pattern to `DEBUG`.
 - `http://www.example.com/?loglevel=ERROR&loglevel-inject=INFO` changes the standard log level error, but enables messages at the `INFO` level for the inject pattern.
 
+### Patternslib global variables
+
+There are some global variables that are available and can be used to make
+global settings or access otherwise hidden objects.
+
+| Global variable | Purpose | Default |
+| --------------- | ------- | ------ |
+| window.__patternslib_import_styles | Whether to import pattern-specific styles | false |
+| window.__patternslib_patterns_blacklist | A list of patterns that should not be loaded. | [] |
+| window.__patternslib_registry | Global access to the Patternslib registry object. | - |
+| window.__patternslib_registry_initialized | True, if the registry has been initialized. | false |
+| window.__patternslib_disable_modernizr (Deprecated) | Disable modernizr, but still write the js/no-js classes to the body. | undefined |
 
 ### Bundle build analyzation
 

src/core/registry.js

@@ -219,6 +219,17 @@ const registry = {
             log.error("Pattern lacks a name.", pattern);
             return false;
         }
+
+        // Do not register blacklisted patterns.
+        let BLACKLIST = window.__patternslib_patterns_blacklist;
+        if (!Array.isArray(BLACKLIST)) {
+            BLACKLIST = [];
+        }
+        if (BLACKLIST.includes(name)) {
+            log.warn(`Pattern name ${name} is blacklisted.`);
+            return false;
+        }
+
         if (registry.patterns[name]) {
             log.debug(`Already have a pattern called ${name}.`);
             return false;

src/core/registry.test.js

@@ -116,4 +116,38 @@ describe("pat-registry: The registry for patterns", function () {
         expect(() => { registry.scan(el) }).not.toThrow(DOMException);
     });
 
+    it("Does not initialize the pattern if blacklisted", function () {
+        window.__patternslib_patterns_blacklist = ["example"];
+
+        Base.extend({
+            name: "example",
+            trigger: ".pat-example",
+            init: function () {
+                this.el.innerHTML = "initialized";
+            },
+        });
+
+        const tree = document.createElement("div");
+        tree.setAttribute("class", "pat-example");
+        registry.scan(tree);
+        expect(tree.textContent).toBe("");
+    });
+
+    it("but also doesn't break with invalid blacklists", function () {
+        window.__patternslib_patterns_blacklist = "example"; // not an array
+
+        Base.extend({
+            name: "example",
+            trigger: ".pat-example",
+            init: function () {
+                this.el.innerHTML = "initialized";
+            },
+        });
+
+        const tree = document.createElement("div");
+        tree.setAttribute("class", "pat-example");
+        registry.scan(tree);
+        expect(tree.textContent).toBe("initialized");
+    });
+
 });