Select from JSON

Documentation

• Class name: SaltSelectFromJSON
• Category: SALT/JSON
• Output node: False

This node is designed to select a specific item from a JSON structure based on a given JSON path and match index. It allows for precise extraction of data from complex JSON inputs, facilitating targeted data retrieval and manipulation.

Input types

Required

• json_input
  • The JSON string from which data will be selected. It serves as the primary data source for the selection process.
  • Comfy dtype: STRING
  • Python dtype: str
• json_path
  • The JSONPath expression used to specify the item to be selected from the JSON input. It defines the path to the target data within the JSON structure.
  • Comfy dtype: STRING
  • Python dtype: str
• match_index
  • The index of the match to be selected when multiple items match the JSONPath expression. It determines which item is chosen if the path yields more than one result.
  • Comfy dtype: INT
  • Python dtype: int

Output types

• selection
  • Comfy dtype: STRING
  • The selected item from the JSON input, returned as a JSON string. It represents the outcome of the selection process based on the provided path and index.
  • Python dtype: str

Usage tips

• Infra type: CPU
• Common nodes: unknown

Source code

class SaltSelectFromJSON:
    @classmethod
    def INPUT_TYPES(cls):
        return {
            "required": {
                "json_input": ("STRING", {"forceInput": True}),
                "json_path": ("STRING", {"multiline": False}),
                "match_index": ("INT", {"default": 0, "min": 0, "max": 99999})
            }
        }

    RETURN_TYPES = ("STRING",)
    RETURN_NAMES = ("selection",)

    FUNCTION = "select"
    CATEGORY = f"{MENU_NAME}/JSON"

    def select(self, json_input, json_path, match_index):
        try:
            json_data = json.loads(json_input)
        except json.JSONDecodeError as e:
            raise Exception(f"Error in JSON formatting: {e}")
        jsonpath_expr = parse(json_path)
        matches = [match.value for match in jsonpath_expr.find(json_data)]
        if matches:
            if match_index >= len(matches):
                match_index = len(matches) - 1
            return (json.dumps(matches[match_index]),)
        else:
            return ("{}",)