Add: option to allow headings under certain node types (#53)

Author: laysent

lib/index.js

@@ -9,7 +9,7 @@ var contents = require('./contents')
 function toc(node, options) {
   var settings = options || {}
   var heading = settings.heading ? toExpression(settings.heading) : null
-  var result = search(node, heading, settings.maxDepth || 6)
+  var result = search(node, heading, settings)
   var map = result.map
 
   result.map = map.length === 0 ? null : contents(map, settings.tight)

lib/search.js

@@ -4,15 +4,18 @@ module.exports = search
 
 var toString = require('mdast-util-to-string')
 var visit = require('unist-util-visit')
+var is = require('unist-util-is')
 var slugs = require('github-slugger')()
 
 var HEADING = 'heading'
 
 // Search a node for a location.
-function search(root, expression, maxDepth) {
+function search(root, expression, settings) {
   var length = root.children.length
   var depth = null
   var lookingForToc = expression !== null
+  var maxDepth = settings.maxDepth || 6
+  var parents = settings.parents || root
   var map = []
   var headingIndex
   var closingIndex
@@ -43,7 +46,7 @@ function search(root, expression, maxDepth) {
     var value = toString(child)
     var id = child.data && child.data.hProperties && child.data.hProperties.id
 
-    if (parent !== root) {
+    if (!is(parents, parent)) {
       return
     }
 

package.json

@@ -22,6 +22,7 @@
   "dependencies": {
     "github-slugger": "^1.1.1",
     "mdast-util-to-string": "^1.0.2",
+    "unist-util-is": "^2.1.2",
     "unist-util-visit": "^1.1.0"
   },
   "devDependencies": {

readme.md

@@ -60,6 +60,7 @@ If no `heading` is specified, creates a table of contents for all headings in
 
 Links to headings are based on GitHub’s style.
 Only top-level headings (those not in blockquotes or lists), are used.
+(Change this default behavior by using option `parents` as described below)
 The given node is not modified.
 
 ##### `options`
@@ -79,6 +80,28 @@ This is inclusive, thus, when set to `3`, level three headings, are included
 
 Whether to compile list-items tightly (`boolean?`, default: `false`).
 
+###### `options.parents`
+
+Allows headings to be children of certain node types.
+Internally, it uses
+[unist-util-is](https://github.com/syntax-tree/unist-util-is) to check.
+Hence all types that can be passed in as first parameter can be used here,
+including `Function`, `string`, `Object` and `Array.<Test>`.
+Check
+[documentation](https://github.com/syntax-tree/unist-util-is#readme)
+for details.
+(default: the first parameter `node`, which only allows top-level headings)
+
+Example:
+
+```json
+{
+  "parents": ["root", "blockquote"]
+}
+```
+
+This would allow headings under either `root` or `blockquote` to be used.
+
 ##### Returns
 
 An object representing the table of contents.

test/fixtures/deep-headings-with-config/config.json

@@ -0,0 +1,3 @@
+{
+  "parents": ["root", "blockquote"]
+}

test/fixtures/deep-headings-with-config/input.md

@@ -0,0 +1,11 @@
+# Something if
+
+## Something else
+
+Text.
+
+> ## heading in a blockquote
+
+* ## heading in a list
+
+# Something iffi

test/fixtures/deep-headings-with-config/output.json

@@ -0,0 +1,110 @@
+{
+  "index": null,
+  "endIndex": null,
+  "map": {
+    "type": "list",
+    "ordered": false,
+    "spread": true,
+    "children": [
+      {
+        "type": "listItem",
+        "loose": true,
+        "spread": true,
+        "children": [
+          {
+            "type": "paragraph",
+            "children": [
+              {
+                "type": "link",
+                "title": null,
+                "url": "#something-if",
+                "children": [
+                  {
+                    "type": "text",
+                    "value": "Something if"
+                  }
+                ]
+              }
+            ]
+          },
+          {
+            "type": "list",
+            "ordered": false,
+            "spread": false,
+            "children": [
+              {
+                "type": "listItem",
+                "loose": false,
+                "spread": false,
+                "children": [
+                  {
+                    "type": "paragraph",
+                    "children": [
+                      {
+                        "type": "link",
+                        "title": null,
+                        "url": "#something-else",
+                        "children": [
+                          {
+                            "type": "text",
+                            "value": "Something else"
+                          }
+                        ]
+                      }
+                    ]
+                  }
+                ]
+              },
+              {
+                "type": "listItem",
+                "loose": false,
+                "spread": false,
+                "children": [
+                  {
+                    "type": "paragraph",
+                    "children": [
+                      {
+                        "type": "link",
+                        "title": null,
+                        "url": "#heading-in-a-blockquote",
+                        "children": [
+                          {
+                            "type": "text",
+                            "value": "heading in a blockquote"
+                          }
+                        ]
+                      }
+                    ]
+                  }
+                ]
+              }
+            ]
+          }
+        ]
+      },
+      {
+        "type": "listItem",
+        "loose": false,
+        "spread": false,
+        "children": [
+          {
+            "type": "paragraph",
+            "children": [
+              {
+                "type": "link",
+                "title": null,
+                "url": "#something-iffi",
+                "children": [
+                  {
+                    "type": "text",
+                    "value": "Something iffi"
+                  }
+                ]
+              }
+            ]
+          }
+        ]
+      }
+    ]
+  }
+}