feat(YfmHeading): support folding attribute (#285)

Author: d3m1d0v

src/extensions/yfm/YfmHeading/YfmHeadingSpecs/const.ts

@@ -7,4 +7,5 @@ export const YfmHeadingAttr = {
     Level: headingLevelAttr,
     Id: 'id',
     DataLine: 'data-line',
+    Folding: 'folding',
 } as const;

src/extensions/yfm/YfmHeading/YfmHeadingSpecs/index.ts

@@ -24,6 +24,7 @@ export const YfmHeadingSpecs: ExtensionAuto<YfmHeadingSpecsOptions> = (builder,
                 [YfmHeadingAttr.Id]: {default: ''},
                 [YfmHeadingAttr.Level]: {default: 1},
                 [YfmHeadingAttr.DataLine]: {default: null},
+                [YfmHeadingAttr.Folding]: {default: false},
             },
             content: '(text | inline)*',
             group: 'block',
@@ -40,11 +41,13 @@ export const YfmHeadingSpecs: ExtensionAuto<YfmHeadingSpecsOptions> = (builder,
             toDOM(node) {
                 const id = node.attrs[YfmHeadingAttr.Id];
                 const lineNumber = node.attrs[YfmHeadingAttr.DataLine];
+                const folding = node.attrs[YfmHeadingAttr.Folding];
                 return [
                     'h' + node.attrs[YfmHeadingAttr.Level],
                     {
                         id: id || null,
                         [YfmHeadingAttr.DataLine]: lineNumber,
+                        [`data-${YfmHeadingAttr.Folding}`]: folding ? '' : null,
                     },
                     0,
                     // [
@@ -84,13 +87,17 @@ export const YfmHeadingSpecs: ExtensionAuto<YfmHeadingSpecsOptions> = (builder,
                     // attrs have id only if it explicitly specified manually
                     return {
                         [YfmHeadingAttr.Level]: Number(token.tag.slice(1)),
+                        [YfmHeadingAttr.Folding]: token.meta?.folding,
                         ...attrs,
                     };
                 },
             },
         },
         toMd: (state, node) => {
-            state.write(state.repeat('#', node.attrs[YfmHeadingAttr.Level]) + ' ');
+            const folding = node.attrs[YfmHeadingAttr.Folding];
+            const level = node.attrs[YfmHeadingAttr.Level];
+
+            state.write(state.repeat('#', level) + (folding ? '+' : '') + ' ');
             state.renderInline(node);
 
             const anchor = node.attrs[YfmHeadingAttr.Id];

src/extensions/yfm/YfmHeading/YfmHeadingSpecs/utils.ts

@@ -8,7 +8,8 @@ export const getNodeAttrs =
     (level: HeadingLevel): TagParseRule['getAttrs'] =>
     (node) => ({
         [YfmHeadingAttr.Level]: level,
-        [YfmHeadingAttr.Id]: (node as Element).getAttribute('id') || '',
+        [YfmHeadingAttr.Id]: node.getAttribute('id') || '',
+        [YfmHeadingAttr.Folding]: node.hasAttribute(`data-${YfmHeadingAttr.Folding}`),
     });
 
 // export const slugify = (str: string) =>

src/extensions/yfm/YfmHeading/commands.ts

@@ -12,16 +12,20 @@ export {resetHeading} from '../../markdown/Heading/commands';
 export const toHeading =
     (level: HeadingLevel): Command =>
     (state, dispatch, view) => {
+        const attrs: Record<string, any> = {};
+
         const parentHeading = findParentNodeOfType(hType(state.schema))(state.selection);
-        if (parentHeading && parentHeading.node.attrs[headingLevelAttr] === level) {
-            return toParagraph(state, dispatch, view);
+        if (parentHeading) {
+            if (parentHeading.node.attrs[headingLevelAttr] === level) {
+                return toParagraph(state, dispatch, view);
+            }
+
+            Object.assign(attrs, parentHeading.node.attrs);
         }
 
         // const text = state.selection.$head.parent.textContent;
-        const attrs = {
-            // [YfmHeadingAttr.Id]: slugify(text),
-            [YfmHeadingAttr.Level]: level,
-        };
+        // attrs[YfmHeadingAttr.Id] = slugify(text);
+        attrs[YfmHeadingAttr.Level] = level;
 
         return setBlockType(hType(state.schema), attrs)(state, dispatch);
     };