ComfyUI Node: Get Parameter From List

Get Parameter From List:

The JNodes_GetParameterFromList node is designed to extract specific parameters from a provided list of parameters. This node is particularly useful when you need to retrieve and utilize specific values from a structured list, such as configuration settings or metadata. By specifying the parameter name and other relevant details, this node can efficiently parse the list and return the desired parameter in the specified format. Additionally, it offers the option to add the extracted parameter to PNG metadata, which can be beneficial for tracking and documentation purposes. This node simplifies the process of parameter extraction, making it easier to manage and utilize parameters in your workflows.

Get Parameter From List Input Parameters:

parameter_list

This parameter accepts a string containing the list of parameters to be parsed. The list should be structured with each parameter enclosed in angle brackets and prefixed by a parsing key. For example, <params:my_string_variable:string>. This input is essential as it provides the source from which the desired parameter will be extracted. The default value is a hint text showing the expected format.

parsing_key

This parameter specifies the key used to identify and parse the parameters within the parameter_list. It helps the node to locate and extract the relevant parameters. The default value is params.

parameter_name

This parameter indicates the name of the parameter to be extracted from the parameter_list. It is a required input and must match the name of the parameter within the list.

return_type

This parameter defines the type of the returned value. It can be set to auto or string, determining how the extracted parameter should be interpreted and returned. The default behavior is to automatically determine the type.

add_to_png_info

This boolean parameter determines whether the extracted parameter should be added to the PNG metadata. If set to True, the parameter will be included in the metadata, which can be useful for documentation and tracking. The default value is True.

parameter_default

This optional parameter provides a default value to be used if the specified parameter_name is not found in the parameter_list. It ensures that the node can still return a value even if the parameter is missing.

extra_pnginfo

This hidden parameter is used internally to store additional PNG metadata. It is not intended to be set manually by the user.

Get Parameter From List Output Parameters:

param

The output parameter param contains the value of the extracted parameter from the parameter_list. The type of this value is determined by the return_type input parameter. This output is crucial as it provides the extracted parameter for further use in your workflow.

Get Parameter From List Usage Tips:

• Ensure that your parameter_list is correctly formatted with each parameter enclosed in angle brackets and prefixed by the parsing key.
• Use the parameter_default input to provide a fallback value in case the specified parameter is not found in the list.
• Set add_to_png_info to True if you need to include the extracted parameter in the PNG metadata for documentation purposes.

Get Parameter From List Common Errors and Solutions:

Did not find parameter_name '<parameter_name>' in parameter_list. Using '<parameter_default>'.

• Explanation: This error occurs when the specified parameter_name is not found in the parameter_list.
• Solution: Ensure that the parameter_name is correctly specified and exists in the parameter_list. You can also provide a suitable parameter_default value to avoid this error.

Invalid return type specified.

• Explanation: This error occurs when an invalid return_type is provided.
• Solution: Ensure that the return_type is set to either auto or string.

Parsing key not found in parameter list.

• Explanation: This error occurs when the specified parsing_key is not found in the parameter_list.
• Solution: Verify that the parsing_key is correctly specified and matches the key used in the parameter_list.