Accessibility

This CDP domain is experimental.

• Types

• Commands

• Events

Types

Generally, you do not need to instantiate CDP types yourself. Instead, the API creates objects for you as return values from commands, and then you can use those objects as arguments to other commands.

class AXNodeId

Unique accessibility node identifier.

class AXValueType(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Enum of possible property types.

BOOLEAN = 'boolean'

TRISTATE = 'tristate'

BOOLEAN_OR_UNDEFINED = 'booleanOrUndefined'

IDREF = 'idref'

IDREF_LIST = 'idrefList'

INTEGER = 'integer'

NODE = 'node'

NODE_LIST = 'nodeList'

NUMBER = 'number'

STRING = 'string'

COMPUTED_STRING = 'computedString'

TOKEN = 'token'

TOKEN_LIST = 'tokenList'

DOM_RELATION = 'domRelation'

ROLE = 'role'

INTERNAL_ROLE = 'internalRole'

VALUE_UNDEFINED = 'valueUndefined'

class AXValueSourceType(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Enum of possible property sources.

ATTRIBUTE = 'attribute'

IMPLICIT = 'implicit'

STYLE = 'style'

CONTENTS = 'contents'

PLACEHOLDER = 'placeholder'

RELATED_ELEMENT = 'relatedElement'

class AXValueNativeSourceType(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Enum of possible native property sources (as a subtype of a particular AXValueSourceType).

DESCRIPTION = 'description'

FIGCAPTION = 'figcaption'

LABEL = 'label'

LABELFOR = 'labelfor'

LABELWRAPPED = 'labelwrapped'

LEGEND = 'legend'

RUBYANNOTATION = 'rubyannotation'

TABLECAPTION = 'tablecaption'

TITLE = 'title'

OTHER = 'other'

class AXValueSource(type_, value=None, attribute=None, attribute_value=None, superseded=None, native_source=None, native_source_value=None, invalid=None, invalid_reason=None)

A single source for a computed AX property.

type_: AXValueSourceType

What type of source this is.

value: Optional[AXValue] = None

The value of this property source.

attribute: Optional[str] = None

The name of the relevant attribute, if any.

attribute_value: Optional[AXValue] = None

The value of the relevant attribute, if any.

superseded: Optional[bool] = None

Whether this source is superseded by a higher priority source.

native_source: Optional[AXValueNativeSourceType] = None

The native markup source for this value, e.g. a <label> element.

native_source_value: Optional[AXValue] = None

The value, such as a node or node list, of the native source.

invalid: Optional[bool] = None

Whether the value for this property is invalid.

invalid_reason: Optional[str] = None

Reason for the value being invalid, if it is.

class AXRelatedNode(backend_dom_node_id, idref=None, text=None)

backend_dom_node_id: BackendNodeId

The BackendNodeId of the related DOM node.

idref: Optional[str] = None

The IDRef value provided, if any.

text: Optional[str] = None

The text alternative of this node in the current context.

class AXProperty(name, value)

name: AXPropertyName

The name of this property.

value: AXValue

The value of this property.

class AXValue(type_, value=None, related_nodes=None, sources=None)

A single computed AX property.

type_: AXValueType

The type of this value.

value: Optional[Any] = None

The computed value of this property.

related_nodes: Optional[List[AXRelatedNode]] = None

One or more related nodes, if applicable.

sources: Optional[List[AXValueSource]] = None

The sources which contributed to the computation of this property.

class AXPropertyName(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)

Values of AXProperty name: - from ‘busy’ to ‘roledescription’: states which apply to every AX node - from ‘live’ to ‘root’: attributes which apply to nodes in live regions - from ‘autocomplete’ to ‘valuetext’: attributes which apply to widgets - from ‘checked’ to ‘selected’: states which apply to widgets - from ‘activedescendant’ to ‘owns’ - relationships between elements other than parent/child/sibling.

ACTIONS = 'actions'

BUSY = 'busy'

DISABLED = 'disabled'

EDITABLE = 'editable'

FOCUSABLE = 'focusable'

FOCUSED = 'focused'

HIDDEN = 'hidden'

HIDDEN_ROOT = 'hiddenRoot'

INVALID = 'invalid'

KEYSHORTCUTS = 'keyshortcuts'

SETTABLE = 'settable'

ROLEDESCRIPTION = 'roledescription'

LIVE = 'live'

ATOMIC = 'atomic'

RELEVANT = 'relevant'

ROOT = 'root'

AUTOCOMPLETE = 'autocomplete'

HAS_POPUP = 'hasPopup'

LEVEL = 'level'

MULTISELECTABLE = 'multiselectable'

ORIENTATION = 'orientation'

MULTILINE = 'multiline'

READONLY = 'readonly'

REQUIRED = 'required'

VALUEMIN = 'valuemin'

VALUEMAX = 'valuemax'

VALUETEXT = 'valuetext'

CHECKED = 'checked'

EXPANDED = 'expanded'

MODAL = 'modal'

PRESSED = 'pressed'

SELECTED = 'selected'

ACTIVEDESCENDANT = 'activedescendant'

CONTROLS = 'controls'

DESCRIBEDBY = 'describedby'

DETAILS = 'details'

ERRORMESSAGE = 'errormessage'

FLOWTO = 'flowto'

LABELLEDBY = 'labelledby'

OWNS = 'owns'

URL = 'url'

class AXNode(node_id, ignored, ignored_reasons=None, role=None, chrome_role=None, name=None, description=None, value=None, properties=None, parent_id=None, child_ids=None, backend_dom_node_id=None, frame_id=None)

A node in the accessibility tree.

node_id: AXNodeId

Unique identifier for this node.

ignored: bool

Whether this node is ignored for accessibility

ignored_reasons: Optional[List[AXProperty]] = None

Collection of reasons why this node is hidden.

role: Optional[AXValue] = None

This Node’s role, whether explicit or implicit.

chrome_role: Optional[AXValue] = None

This Node’s Chrome raw role.

name: Optional[AXValue] = None

The accessible name for this Node.

description: Optional[AXValue] = None

The accessible description for this Node.

value: Optional[AXValue] = None

The value for this Node.

properties: Optional[List[AXProperty]] = None

All other properties

parent_id: Optional[AXNodeId] = None

ID for this node’s parent.

child_ids: Optional[List[AXNodeId]] = None

IDs for each of this node’s child nodes.

backend_dom_node_id: Optional[BackendNodeId] = None

The backend ID for the associated DOM node, if any.

frame_id: Optional[FrameId] = None

The frame ID for the frame associated with this nodes document.

Commands

Each command is a generator function. The return type Generator[x, y, z] indicates that the generator yields arguments of type x, it must be resumed with an argument of type y, and it returns type z. In this library, types x and y are the same for all commands, and z is the return type you should pay attention to. For more information, see Getting Started: Commands.

disable()

Disables the accessibility domain.

Return type:

Generator[Dict[str, Any], Dict[str, Any], None]

enable()

Enables the accessibility domain which causes AXNodeId’s to remain consistent between method calls. This turns on accessibility for the page, which can impact performance until accessibility is disabled.

Return type:

Generator[Dict[str, Any], Dict[str, Any], None]

get_ax_node_and_ancestors(node_id=None, backend_node_id=None, object_id=None)

Fetches a node and all ancestors up to and including the root. Requires enable() to have been called previously.

EXPERIMENTAL

Parameters:

• node_id (Optional[NodeId]) – (Optional) Identifier of the node to get.

• backend_node_id (Optional[BackendNodeId]) – (Optional) Identifier of the backend node to get.

• object_id (Optional[RemoteObjectId]) – (Optional) JavaScript object id of the node wrapper to get.

Return type:

Generator[Dict[str, Any], Dict[str, Any], List[AXNode]]

Returns:

get_child_ax_nodes(id_, frame_id=None)

Fetches a particular accessibility node by AXNodeId. Requires enable() to have been called previously.

EXPERIMENTAL

Parameters:

• id –

• frame_id (Optional[FrameId]) – (Optional) The frame in whose document the node resides. If omitted, the root frame is used.

Return type:

Generator[Dict[str, Any], Dict[str, Any], List[AXNode]]

Returns:

get_full_ax_tree(depth=None, frame_id=None)

Fetches the entire accessibility tree for the root Document

EXPERIMENTAL

Parameters:

• depth (Optional[int]) – (Optional) The maximum depth at which descendants of the root node should be retrieved. If omitted, the full tree is returned.

• frame_id (Optional[FrameId]) – (Optional) The frame for whose document the AX tree should be retrieved. If omitted, the root frame is used.

Return type:

Generator[Dict[str, Any], Dict[str, Any], List[AXNode]]

Returns:

get_partial_ax_tree(node_id=None, backend_node_id=None, object_id=None, fetch_relatives=None)

Fetches the accessibility node and partial accessibility tree for this DOM node, if it exists.

EXPERIMENTAL

Parameters:

• node_id (Optional[NodeId]) – (Optional) Identifier of the node to get the partial accessibility tree for.

• backend_node_id (Optional[BackendNodeId]) – (Optional) Identifier of the backend node to get the partial accessibility tree for.

• object_id (Optional[RemoteObjectId]) – (Optional) JavaScript object id of the node wrapper to get the partial accessibility tree for.

• fetch_relatives (Optional[bool]) – (Optional) Whether to fetch this node’s ancestors, siblings and children. Defaults to true.

Return type:

Generator[Dict[str, Any], Dict[str, Any], List[AXNode]]

Returns:

The Accessibility.AXNode for this DOM node, if it exists, plus its ancestors, siblings and children, if requested.

get_root_ax_node(frame_id=None)

Fetches the root node. Requires enable() to have been called previously.

EXPERIMENTAL

Parameters:

frame_id (Optional[FrameId]) – (Optional) The frame in whose document the node resides. If omitted, the root frame is used.

Return type:

Generator[Dict[str, Any], Dict[str, Any], AXNode]

Returns:

query_ax_tree(node_id=None, backend_node_id=None, object_id=None, accessible_name=None, role=None)

Query a DOM node’s accessibility subtree for accessible name and role. This command computes the name and role for all nodes in the subtree, including those that are ignored for accessibility, and returns those that match the specified name and role. If no DOM node is specified, or the DOM node does not exist, the command returns an error. If neither accessibleName or role is specified, it returns all the accessibility nodes in the subtree.

EXPERIMENTAL

Parameters:

• node_id (Optional[NodeId]) – (Optional) Identifier of the node for the root to query.

• backend_node_id (Optional[BackendNodeId]) – (Optional) Identifier of the backend node for the root to query.

• object_id (Optional[RemoteObjectId]) – (Optional) JavaScript object id of the node wrapper for the root to query.

• accessible_name (Optional[str]) – (Optional) Find nodes with this computed name.

• role (Optional[str]) – (Optional) Find nodes with this computed role.

Return type:

Generator[Dict[str, Any], Dict[str, Any], List[AXNode]]

Returns:

A list of Accessibility.AXNode matching the specified attributes, including nodes that are ignored for accessibility.

Events

Generally, you do not need to instantiate CDP events yourself. Instead, the API creates events for you and then you use the event’s attributes.

class LoadComplete(root)

EXPERIMENTAL

The loadComplete event mirrors the load complete event sent by the browser to assistive technology when the web page has finished loading.

root: AXNode

New document root node.

class NodesUpdated(nodes)

EXPERIMENTAL

The nodesUpdated event is sent every time a previously requested node has changed the in tree.

nodes: List[AXNode]

Updated node data.