About ResourceReferences

Interface org.apache.nifi.components.resource.ResourceReferences; Part of the Java Framework

The PythonPropertyValue asResources() method returns an instance of a proxy object implementing the ResourceReferences interface. The ResourceReferences object holds a collection of individual resources.

Attributes

Name	Type	Description
`asList()`	Callable	Returns List(`ResourceReference`); A List representation of all Resource References; See ResourceReference
`asLocations()`	Callable	Return List(String); A list of all Resource References' locations
`getCount()`	Callable	Returns Integer; The number of Resource References held

e.g.:

from nifiapi.flowfilesource import (
    FlowFileSource,
    FlowFileSourceResult,
)
from nifiapi.properties import (
    ProcessContext,
    PropertyDescriptor,
    ResourceDefinition
)
from typing import List
from json import dumps


class Processor(FlowFileSource):
    (...)

    PROPERTY = PropertyDescriptor(
        name="Example Property",
        description='''
        This property accepts multiple resource references.

        Allowed resources are: URLs, files and directories
        ''',
        required=True,
        resource_definition=ResourceDefinition(
            allow_multiple=True,
            allow_file=True,
            allow_directory=True,
            allow_url=True,
        )
    )

    (...)

    def get_resources_summary(
        self, context: ProcessContext, descriptor: PropertyDescriptor
    ) -> List[dict]:
        '''
        Get a summary of all resources provided for a property supporting
        multiple resource references.

        Parameters:
            context (ProcessContext)
            descriptor (PropertyDescriptor)

        Returns:
            List(Dict)
        '''
        resources = context.getProperty(descriptor).asResources()
        summary = []
        for resource in resources.asList():
            summary.append({
                "type": resource.getResourceType().toString(),
                "location": resource.getLocation(),
                "is_accessible": resource.isAccessible()
            })

        self.logger.debug(dumps(summary, indent=4))

        return summary

Consider a following example:
Input string: https://google.com, /tmp/movie-list/movies.json, /tmp/movie-list
Logger output:

[
    {
        "type": "URL",
        "location": "https://google.com",
        "is_accessible": true
    },
    {
        "type": "file",
        "location": "/tmp/movie-list/movies.json",
        "is_accessible": true
    },
    {
        "type": "directory",
        "location": "/tmp/movie-list",
        "is_accessible": true
    }
]

Attributes​

Attributes