Add getDescendants and getDescendantsOfType to tranforms

1 files changed, 32 insertions, 2 deletions

diff --git a/lib/transforms.js b/lib/transforms.js
index 5078387..22be1af 100644
--- a/lib/transforms.js
+++ b/lib/transforms.js
@@ -1,6 +1,10 @@
 var _ = require("underscore");
 
-exports.paragraph = function(transform) {
+exports.paragraph = paragraph;
+exports.getDescendantsOfType = getDescendantsOfType;
+exports.getDescendants = getDescendants;
+
+function paragraph(transform) {
     function transformElement(element) {
         if (element.children) {
             var children = _.map(element.children, transformElement);
@@ -14,4 +18,30 @@ exports.paragraph = function(transform) {
         return element;
     }
     return transformElement;
-};
+}
+
+
+function getDescendantsOfType(element, type) {
+    return getDescendants(element).filter(function(descendant) {
+        return descendant.type === type;
+    });
+}
+
+function getDescendants(element) {
+    var descendants = [];
+
+    visitDescendants(element, function(descendant) {
+        descendants.push(descendant);
+    });
+
+    return descendants;
+}
+
+function visitDescendants(element, visit) {
+    if (element.children) {
+        element.children.forEach(function(child) {
+            visitDescendants(child, visit);
+            visit(child);
+        });
+    }
+}