Add getDefaultInitInfo option in run command

README.md

@@ -78,9 +78,37 @@ sandbox.run();
 
 The sandbox module provides the following methods:
 
-`run` - Runs the sandbox. A promise will be returned that will be resolved once the server is ready.
+### `run`
 
-`init` - Initializes sandbox configuration files. A promise will be returned that will be resolved once the files have been generated.
+Runs the sandbox. A promise will be returned that will be resolved once the server is ready.
+
+You can provide a function option `getDefaultInitInfo` to modify the init info for a component as follows:
+
+```js
+const sandbox = require('@adobe/reactor-sandbox');
+const getDefaultInitInfo = ({ info, type, name }) => {
+  if (type === 'actions') {
+    info.extensionSettings = {
+      myrequiredsetting: 'myvalue'
+    };
+  }
+  return info;
+};
+
+sandbox.run({ getDefaultInitInfo });
+```
+
+In this example the extensionSettings are defaulted to a different value. This may be useful if some of your components use required values from the extensionSettings to render. In the view sandbox `getDefaultInitInfo` will be called whenever a component loads for the first time, or when you click reset in the init tab. `getDefaultInitInfo` is called with the following options:
+
+- `info` - The default init info as generated by reactor-sandbox.
+- `type` - The component type. (One of "configuration", "events", "conditions", "actions", "dataElements")
+- `name` - The name of the component as specified in extension.json. (For "configuration" types this is null.)
+
+The return value will be used as the default initInfo when initializing your components.
+
+### `init`
+
+Initializes sandbox configuration files. A promise will be returned that will be resolved once the files have been generated.
 
 ## Contributing