Implement "splitBlockAtRange" as a node method (#336)

src/models/node.js

@@ -458,6 +458,85 @@ const Node = {
         .getDepth(key, startAt + 1)
   },
 
+  /**
+   * Split a node by `path` at `offset`.
+   *
+   * @param {String} path
+   * @param {Number} offset
+   * @return {Node}
+   */
+
+   splitNode(path, offset) {
+       let base = this
+       let node = base.assertPath(path)
+       let parent = base.getParent(node)
+       const isParent = base == parent
+       const index = parent.nodes.indexOf(node)
+
+       let child = node
+       let one
+       let two
+
+       if (node.kind != 'text') {
+         child = node.getTextAtOffset(offset)
+       }
+
+       while (child && child != parent) {
+         if (child.kind == 'text') {
+           const i = node.kind == 'text' ? offset : offset - node.getOffset(child)
+           const { characters } = child
+           const oneChars = characters.take(i)
+           const twoChars = characters.skip(i)
+           one = child.merge({ characters: oneChars })
+           two = child.merge({ characters: twoChars, key: uid() })
+         }
+
+         else {
+           const { nodes } = child
+           const oneNodes = nodes.takeUntil(n => n.key == one.key).push(one)
+           const twoNodes = nodes.skipUntil(n => n.key == one.key).rest().unshift(two)
+           one = child.merge({ nodes: oneNodes })
+           two = child.merge({ nodes: twoNodes, key: uid() })
+         }
+
+         child = base.getParent(child)
+       }
+
+       parent = parent.removeNode(index)
+       parent = parent.insertNode(index, two)
+       parent = parent.insertNode(index, one)
+       base = isParent ? parent : base.updateDescendant(parent)
+       return base
+   },
+
+  /**
+   * Split the block nodes at a `range`, to optional `height`.
+   *
+   * @param {Selection} range
+   * @param {Number} height (optional)
+   * @return {Node}
+   */
+
+  splitBlockAtRange(range, height = 1) {
+      const { startKey, startOffset } = range
+      let base = this
+      let node = base.assertDescendant(startKey)
+      let parent = base.getClosestBlock(node)
+      let offset = startOffset
+      let h = 0
+
+      while (parent && parent.kind == 'block' && h < height) {
+        offset += parent.getOffset(node)
+        node = parent
+        parent = base.getClosestBlock(parent)
+        h++
+      }
+
+      const path = base.getPath(node.key)
+      return this.splitNode(path, offset)
+        .normalize()
+  },
+
   /**
    * Get a fragment of the node at a `range`.
    *

src/transforms/apply-operation.js

@@ -312,44 +312,9 @@ function setSelection(state, operation) {
 function splitNode(state, operation) {
   const { path, offset } = operation
   let { document } = state
-  let node = document.assertPath(path)
-  let parent = document.getParent(node)
-  const isParent = document == parent
-  const index = parent.nodes.indexOf(node)
 
-  let child = node
-  let one
-  let two
+  document = document.splitNode(path, offset)
 
-  if (node.kind != 'text') {
-    child = node.getTextAtOffset(offset)
-  }
-
-  while (child && child != parent) {
-    if (child.kind == 'text') {
-      const i = node.kind == 'text' ? offset : offset - node.getOffset(child)
-      const { characters } = child
-      const oneChars = characters.take(i)
-      const twoChars = characters.skip(i)
-      one = child.merge({ characters: oneChars })
-      two = child.merge({ characters: twoChars, key: uid() })
-    }
-
-    else {
-      const { nodes } = child
-      const oneNodes = nodes.takeUntil(n => n.key == one.key).push(one)
-      const twoNodes = nodes.skipUntil(n => n.key == one.key).rest().unshift(two)
-      one = child.merge({ nodes: oneNodes })
-      two = child.merge({ nodes: twoNodes, key: uid() })
-    }
-
-    child = document.getParent(child)
-  }
-
-  parent = parent.removeNode(index)
-  parent = parent.insertNode(index, two)
-  parent = parent.insertNode(index, one)
-  document = isParent ? parent : document.updateDescendant(parent)
   state = state.merge({ document })
   return state
 }