Source code for thutils.loader

# encoding: utf-8

'''
@author: Tsuyoshi Hombashi

:required: https://pypi.python.org/pypi/voluptuous
'''

from __future__ import with_statement
import os
import sys

try:
    import json
except ImportError:
    import simplejson as json

import thutils.common as common
import thutils.gfile as gfile
from thutils.logger import logger


class JsonLoader:

    @classmethod
    def load(cls, json_file_path, schema=None):
        """
        :param str json_file_path:
            json_file_path: path of the json file to be read
            schema: voluptuous schema
        :return: Dictionary storing the parse results of JSON
        :rtype: dictionary
        :raises ImportError:
        :raises InvalidFilePathError:
        :raises FileNotFoundError:
        :raises RuntimeError:
        :raises ValueError:
        """

        gfile.check_file_existence(json_file_path)

        try:
            if not gfile.FileTypeChecker.is_text_file(json_file_path):
                raise ValueError("not a JSON file")
        except ImportError:
            # magicが必要とするライブラリが見つからない (e.g. Windowsでは追加DLLが必要)
            _, e, _ = sys.exc_info()  # for python 2.5 compatibility
            logger.debug(e)

        with open(json_file_path, "r") as fp:
            try:
                dict_json = json.load(fp)
                logger.debug("load json %s:%s" % (
                    json_file_path, common.dump_dict(dict_json)))
            except ValueError:
                _, e, _ = sys.exc_info()  # for python 2.5 compatibility
                raise ValueError(os.linesep.join(
                    [str(e), "decode error: check JSON format with http://jsonlint.com/"]))

        cls.__validate_json(schema, dict_json)

        return dict_json

    @classmethod
    def loads(cls, json_text, schema=None):
        """
        :param str json_text: json text to be parse
        :param voluptuous.Schema schema: schema of voluptuous
        :return: Dictionary storing the parse results of JSON
        :rtype: dictionary
        :raises ImportError:
        :raises RuntimeError:
        :raises ValueError:
        """

        try:
            dict_json = json.loads(json_text)
            logger.debug(
                "load json text:%s" % (common.dump_dict(dict_json)))
        except ValueError:
            _, e, _ = sys.exc_info()  # for python 2.5 compatibility
            raise ValueError(os.linesep.join(
                [str(e), "decode error: check JSON format with http://jsonlint.com/"]))

        cls.__validate_json(schema, dict_json)

        return dict_json

    @staticmethod
    def __validate_json(schema, dict_json):
        if schema is not None:
            schema(dict_json)