Source code for node_json_convert

# Copyright (c) 2019, System Engineering Software Society
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from sympathy.api import node as synode
from sympathy.api.nodeconfig import Port, Ports, Tag, Tags
from sympathy.api import exceptions
from sympathy.api import json


class JsonToDict(synode.Node):
    """
    Convert from JSON input containing a top-level dict to Sympathy
    dictionary (sydict) containing JSON.
    """

    author = 'Erik der Hagopian'
    icon = 'fromjson.svg'
    name = 'Json to Dict'
    nodeid = 'org.sysess.sympathy.json.jsontodict'
    tags = Tags(Tag.DataProcessing.Convert)

    inputs = Ports([Port.Json('JSON', name='json')])
    outputs = Ports([Port.Custom('{json}', 'JSON dict', name='json_dict')])

    def execute(self, node_context):
        data = node_context.input['json'].get()
        if not isinstance(data, dict):
            raise exceptions.SyDataError(
                'Conversion from json to {json} requires top-level dict')
        else:
            output = node_context.output['json_dict']
            for k, v in data.items():
                item = json.File()
                item.set(v)
                output[k] = item


class DictToJson(synode.Node):
    """
    Convert from Sympathy dictionary (sydict) input containing JSON to JSON
    dictionary.
    """

    author = 'Erik der Hagopian'
    icon = 'tojson.svg'
    name = 'Dict to Json'
    nodeid = 'org.sysess.sympathy.json.dicttojson'
    tags = Tags(Tag.DataProcessing.Convert)

    inputs = Ports([Port.Custom('{json}', 'JSON dict', name='json_dict')])
    outputs = Ports([Port.Json('JSON', name='json')])

    def execute(self, node_context):
        node_context.output['json'].set(
            {k: v.get() for k, v in node_context.input['json_dict'].items()})


class JsonToList(synode.Node):
    """
    Convert from Sympathy list (sylist) input containing JSON to JSON
    list.
    """

    author = 'Erik der Hagopian'
    icon = 'fromjson.svg'
    name = 'Json to List'
    nodeid = 'org.sysess.sympathy.json.jsontolist'
    tags = Tags(Tag.DataProcessing.Convert)

    inputs = Ports([Port.Json('JSON', name='json')])
    outputs = Ports([Port.Custom('[json]', 'JSON list', name='json_list')])

    def execute(self, node_context):
        data = node_context.input['json'].get()
        if not isinstance(data, list):
            raise exceptions.SyDataError(
                'Conversion from json to {json} requires top-level list')
        else:
            output = node_context.output['json_list']
            for v in data:
                item = json.File()
                item.set(v)
                output.append(item)


class ListToJson(synode.Node):
    """
    Convert from JSON input containing a top-level list to a Sympathy
    list (sylist) containing JSON.
    """

    author = 'Erik der Hagopian'
    icon = 'tojson.svg'
    name = 'List to Json'
    nodeid = 'org.sysess.sympathy.json.listtojson'
    tags = Tags(Tag.DataProcessing.Convert)

    inputs = Ports([Port.Custom('[json]', 'JSON list', name='json_list')])
    outputs = Ports([Port.Json('JSON', name='json')])

    def execute(self, node_context):
        node_context.output['json'].set(
            [v.get() for v in node_context.input['json_list']])