1 files changed, 37 insertions, 0 deletions
diff --git a/packages/gitbook-core/src/actions/components.js b/packages/gitbook-core/src/actions/components.js
new file mode 100644
index 0000000..89b0c9e
--- /dev/null
+++ b/packages/gitbook-core/src/actions/components.js
@@ -0,0 +1,37 @@
+const ACTION_TYPES = require('./TYPES');
+
+/**
+ * Find all components matching a descriptor
+ * @param {List<ComponentDescriptor>} state
+ * @param {String} matching.role
+ */
+function findMatchingComponents(state, matching) {
+    return state
+    .filter(({descriptor}) => {
+        if (matching.role && matching.role === descriptor.role) {
+            return false;
+        }
+
+        return true;
+    })
+    .map(component => component.Component);
+}
+
+/**
+ * Register a new component
+ * @param  {React.Class} Component
+ * @param  {Descriptor} descriptor
+ * @return {Action}
+ */
+function registerComponent(Component, descriptor) {
+    return {
+        type: ACTION_TYPES.REGISTER_COMPONENT,
+        Component,
+        descriptor
+    };
+}
+
+module.exports = {
+    findMatchingComponents,
+    registerComponent
+};