Amazon Cloud Directory is no longer be open to new customers. For alternatives to Cloud Directory, explore [Amazon DynamoDB](https://aws.amazon.com/dynamodb/) and [Amazon Neptune](https://aws.amazon.com/neptune/). If you need help choosing the right alternative for your use case, or for any other questions, contact [AWS Support](https://aws.amazon.com/support/). 

# Access Objects
<a name="directory_objects_access_objects"></a>

Objects in a directory can be accessed either by path or by `objectIdentifier`.

 **Path** – Every object in a Cloud Directory tree can be identified and found by the pathname that describes how to reach it. The path starts from the root of the directory (Node `000` in the previous figure). The path notation begins with the link labeled with a slash (/) and follows the child links separated by path separator (also a slash) until reaching the last part of the path. For example, object `005` in the previous figure can be identified using the path `/group/a/d`. Multiple paths may identify an object, since objects that are leaf nodes can have multiple parents. The following path can also be used to identify object `005` : /group/b/e

 **ObjectIdentifier** – Every object in the directory has a unique global identifier, which is the `ObjectIdentifier`. `ObjectIdentifier` is returned as part of the [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_CreateObject.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_CreateObject.html) API call. You can also fetch the `ObjectIdentifier` by using [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_GetObjectInformation.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_GetObjectInformation.html) API call. For example, to fetch the object identifier of object `005`, you can call `GetObjectInformation` with object reference as the path that leads to the object, which is group/b/e or group/a/d.

```
GetObjectInformationRequest request = new GetObjectInformationRequest()
    .withDirectoryArn(directoryArn)
    .withObjectReference("/group/b/e")
    .withConsistencyLevel(level)
GetObjectInformationResult result = cdClient.getObjectInformation(request)
String objectIdentifier = result.getObjectIdentifier()
```

## Populating Objects
<a name="directory_objects_access_objects_populatingobjects"></a>

New facets can be added to an object using [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_AddFacetToObject.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_AddFacetToObject.html) API call. The type of the object is determined based on the facets attached to the object. Object attachment in a directory works based on the type of the object. When attaching an object, remember these rules:
+  A leaf node object cannot have children.
+  A node object can have multiple children.
+  An object of the policy type cannot have children and can have zero or one parent.

## Updating Objects
<a name="directory_objects_access_objects_updatingobjects"></a>

You can update an object in multiple ways:

1.  Use the [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_UpdateObjectAttributes.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_UpdateObjectAttributes.html) operation to update individual facet attributes on an object.

1.  Use the [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_AddFacetToObject.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_AddFacetToObject.html) operation to add new facets to an object.

1.  Use the [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_RemoveFacetFromObject.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_RemoveFacetFromObject.html) operation to delete existing facets from an object.

## Deleting Objects
<a name="directory_objects_access_objects_deletingobjects"></a>

An attached object must meet certain conditions before you can delete it from a directory:

1.  You must detach the object from the tree. You can detach an object only when it doesn’t have any children. If the object has children, you must detach all the children first.

1.  You can delete a detached object only if all the attributes on that object are deleted. You can delete attributes on an object by deleting each facet attached to that object. You can fetch a list of facets attached to an object by calling [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_GetObjectInformation.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_GetObjectInformation.html).

1.  An object must also have no parent, no policy attachments, and no index attachments.

Because an object must be fully detached from the tree to be deleted, you must use the object identifier to delete it.

## Querying Objects
<a name="directory_objects_access_objects_queryobjects"></a>

This section discusses various elements relevant for querying objects in a directory.

### Directory Traversal
<a name="directory_objects_access_objects_directorytraversal"></a>

Because Cloud Directory is a tree, you can query objects from the top down using the [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_ListObjectChildren.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_ListObjectChildren.html) API operation or from the bottom up using the [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_ListObjectParents.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_ListObjectParents.html) API operation.

### Policy Lookup
<a name="directory_objects_access_objects_policylookup"></a>

Given an object reference, the [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_LookupPolicy.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_LookupPolicy.html) API operation returns all the policies that are attached along its path (or paths) to the root in a top-down fashion. Any of the paths that are not leading up to the root are ignored. All policy type objects are returned.

If the object is a leaf node, it can have multiple paths to the root. This call returns only one path for each call. To fetch additional paths, use the pagination token. 

### Index Querying
<a name="directory_objects_access_objects_indexquerying"></a>

Cloud Directory supports rich index querying functionality with the use of the following ranges:
+ **FIRST - **Starts from the first indexed attribute value. The start attribute value is optional.
+ **LAST - **Returns attribute values up to the end of the index, including the missing values. The end attribute value is optional.
+ **LAST\$1BEFORE\$1MISSING\$1VALUES - **Returns attribute values up to the end of index, excluding missing values.
+ **INCLUSIVE - **Includes the attribute value being specified.
+ **EXCLUSIVE - **Excludes the attribute value being specified.

### Parent Path Listing
<a name="directory_objects_access_objects_parentpath"></a>

Using the [http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_ListObjectParentPaths.html](http://docs.aws.amazon.com/clouddirectory/latest/APIReference/API_ListObjectParentPaths.html) API call, you can retrieve all available parent paths for any type of object (node, leaf node, policy node, index node). This API operation can be helpful when you need to evaluate all parents for an object. The call returns all the objects from the directory root until the requested object. It also returns the number of paths based on user-defined `MaxResults`, in case of multiple paths to the parent. The order of the paths and nodes returned is consistent among multiple API calls unless the objects are deleted or moved. Paths not leading to the directory root are ignored from the target object.

For an example on how this works, let's say a directory has an object hierarchy similar to the illustration shown below. 

![\[Object hierarchy diagram showing nodes, links, and policy objects in a tree structure.\]](http://docs.aws.amazon.com/clouddirectory/latest/developerguide/images/parent_path.png)


The numbered shapes represent the different objects. The number of arrows between that object and the directory root (`000`) represent the complete path and would be expressed in the output. The following table shows requests and responses from queries made to specific leaf node objects in the hierarchy. 

 


**Example queries on objects**  

| Request | Response | 
| --- | --- | 
| 004, PageToken: null, MaxResults: 1 | [\$1/group/a/c], [000, 001, 002, 004]\$1], PageToken: null | 
| 005, PageToken: null, MaxResults: 2 | [\$1/group/a/d, [000, 001, 002, 005]\$1, \$1 /group/b/e, [000, 001, 003, 005]\$1], PageToken: null In this example, object `005` has both nodes `002` and `003` as parents. Also, since `MaxResults` is 2, both paths display objects in a list.  | 
| 005, PageToken: null, MaxResults: 1 | [\$1/group/a/d, [000, 001, 002, 005]\$1], PageToken: <encrypted\$1next\$1token> | 
| 005, PageToken: <encrypted\$1next\$1token>, MaxResults: 1 | [\$1/group/b/e, [000, 001, 003, 005]\$1], PageToken: null In this example, object `005` has both nodes `002` and `003` as parents. Also, since `MaxResults` is 1, multiple paginated calls with page tokens will be made to get all paths with a list of objects.  | 
| 006, PageToken: null, MaxResults: 1 | [\$1/group/b/f, [000, 001, 003, 006]\$1], PageToken: null | 
| 007, PageToken: null, MaxResults: 1 | [\$1/group/a/index, [000, 001, 002, 007]\$1], PageToken: null |