Feat: bring up "once" module support

posthtml · Dec 9, 2020 · 2da8104 · 2da8104
1 parent c40c99b
commit 2da8104
Showing 1 changed file with 35 additions and 3 deletions.
diff --git a/lib/htmlnano.es6 b/lib/htmlnano.es6
@@ -6,11 +6,14 @@ import maxPreset from './presets/max';
 
 function htmlnano(options = {}, preset = safePreset) {
     return function minifier(tree) {
+        const attrsHandlers = [];
+        const contentsHandlers = [];
+
         options = { ...preset, ...options };
         let promise = Promise.resolve(tree);
 
         for (const [moduleName, moduleOptions] of Object.entries(options)) {
-            if (! moduleOptions) {
+            if (!moduleOptions) {
                 // The module is disabled
                 continue;
             }
@@ -19,8 +22,37 @@ function htmlnano(options = {}, preset = safePreset) {
                 throw new Error('Module "' + moduleName + '" is not defined');
             }
 
-            let module = require('./modules/' + moduleName);
-            promise = promise.then(tree => module.default(tree, options, moduleOptions));
+            const module = require('./modules/' + moduleName);
+
+            if (module.once) {
+                // It is a "once" version of htmlnano module
+                if (module.onattrs) {
+                    attrsHandlers.push(module.onattrs(options, moduleOptions));
+                }
+                if (module.oncontent) {
+                    contentsHandlers.push(module.oncontent(options, moduleOptions));
+                }
+            } else {
+                // It is a traditional htmlnano module
+                promise = promise.then(tree => module.default(tree, options, moduleOptions));
+            }
+        }
+
+        if (attrsHandlers.length + contentsHandlers.length > 0) {
+            promise = promise.then(tree => {
+                tree.walk(node => {
+                    for (const handler of attrsHandlers) {
+                        node.attrs = handler(node.attrs, node);
+                    }
+                    for (const handler of contentsHandlers) {
+                        node.content = handler(node.content, node);
+                    }
+
+                    return node;
+                });
+
+                return tree;
+            });
         }
 
         return promise;