Node

The Node class represents a specific location in JSON data and allows navigation relative to that location. It provides a way to traverse and explore component data with lazy evaluation, meaning data is only accessed when explicitly requested through methods like get_value(), exists(), or iteration.

Data Access Methods

get_value

get_value(path=".")

Gets the raw value at the given path relative to this node.

• path (str): JSON path relative to this node (default: "." for this node's value)

• Returns: The raw value (dict, list, string, number, boolean, etc.)

• Raises: ValueError if the path is invalid or doesn't exist, NoDataError if data is not available yet

Example:

# Get the current node's value
node = check.get_node(".config.database")
host = node.get_value(".host")  # Relative to .config.database
port = node.get_value(".port")  # Relative to .config.database

# Get the node's own value
database_config = node.get_value()  # Returns the entire database config object as a dict

get_node

get_node(path)

Gets a Node at the given path relative to this node. Uses lazy evaluation - data is not accessed until value is needed.

• path (str): JSON path relative to this node

• Returns: A new Node instance at the specified path

• Raises: ValueError if the path syntax is invalid

exists

exists(path=".")

Checks if a path exists relative to this node.

• path (str): JSON path relative to this node (default: "." to check if this node exists)

• Returns: True if the path exists, False otherwise

Example:

host_node = check.get_node(".config.host")
if host_node.exists():
    host = host_node.get_value()

Iteration Methods

Iterating over Node

for item in node:
    # Process item

Makes Node iterable. For dictionaries, yields keys. For arrays, yields Node objects.

• For dict-like data: Yields string keys

• For array-like data: Yields Node objects for each array element

• Raises: ValueError if the node doesn't point to a dict or array, NoDataError if data is not available yet

Example:

# Iterate over dictionary keys
config_node = check.get_node(".config")
for key in config_node:
    print(f"Config key: {key}")

# Iterate over array elements
items_node = check.get_node(".items")
for item_node in items_node:
    name = item_node.get_value(".name")
    print(f"Item name: {name}")

items

items()

Get key-value pairs when this Node points to a dict-like structure.

• Returns: Iterator of (key, Node) tuples for dict-like data

• Raises: ValueError if the node doesn't point to a dictionary, NoDataError if data is not available yet

Example:

config_node = check.get_node(".config")
for key, value_node in config_node.items():
    value = value_node.get_value()
    print(f"{key}: {value}")