| """Variable class for URITemplate.""" | |
| from __future__ import annotations | |
| from .charset import Charset | |
| class VariableInvalidError(Exception): | |
| """Exception thrown for invalid variables.""" | |
| variable: str | |
| def __init__(self, variable: str) -> None: | |
| self.variable = variable | |
| def __str__(self) -> str: | |
| """Convert to string.""" | |
| return 'Bad variable: ' + self.variable | |
| class Variable: | |
| """ | |
| A template variable. | |
| https://tools.ietf.org/html/rfc6570#section-2.3 | |
| """ | |
| name: str | |
| key: str | |
| max_length: int | |
| explode: bool | |
| array: bool | |
| default: (str | None) | |
| def __init__(self, var_spec: str) -> None: | |
| self.name = '' | |
| self.key = '' | |
| self.max_length = 0 | |
| self.explode = False | |
| self.array = False | |
| self.default = None | |
| if (var_spec[0:1] not in Charset.VAR_START): | |
| raise VariableInvalidError(var_spec) | |
| if ('=' in var_spec): | |
| var_spec, self.default = var_spec.split('=', 1) | |
| if (':' in var_spec): | |
| var_spec, max_length = var_spec.split(':', 1) | |
| if ((0 < len(max_length)) and (len(max_length) < 4)): | |
| for digit in max_length: | |
| if (digit not in Charset.DIGIT): | |
| raise VariableInvalidError(var_spec + ':' + max_length) | |
| self.max_length = int(max_length) | |
| if (not self.max_length): | |
| raise VariableInvalidError(var_spec + ':' + max_length) | |
| else: | |
| raise VariableInvalidError(var_spec + ':' + max_length) | |
| elif ('*' == var_spec[-1]): | |
| var_spec = var_spec[:-1] | |
| self.explode = True | |
| elif ('[]' == var_spec[-2:]): | |
| var_spec = var_spec[:-2] | |
| self.array = True | |
| self.explode = True | |
| index = 0 | |
| while (index < len(var_spec)): | |
| codepoint = var_spec[index] | |
| if (('%' == codepoint) | |
| and ((index + 2) < len(var_spec)) | |
| and (var_spec[index + 1] in Charset.HEX_DIGIT) | |
| and (var_spec[index + 2] in Charset.HEX_DIGIT)): | |
| self.key += var_spec[index:index + 3] | |
| index += 2 | |
| elif (codepoint in Charset.VAR_CHAR): | |
| self.key += codepoint | |
| elif ('/' == codepoint): | |
| self.name = self.key | |
| self.key = '' | |
| else: | |
| raise VariableInvalidError(var_spec + ((':' + str(self.max_length)) if (self.max_length) else '') | |
| + ('[]' if (self.array) else ('*' if (self.explode) else ''))) | |
| index += 1 | |
| self.name = (self.name or self.key) | |
| self.key = (self.key or self.name) | |
| def __str__(self) -> str: | |
| """Convert to string.""" | |
| return (self.name + (f'/{self.key}' if (self.key and (self.key != self.name)) else '') | |
| + (f':{self.max_length}' if (self.max_length) else '') | |
| + ('*' if (self.explode and not self.array) else '') + ('[]' if (self.array) else '') | |
| + (f'={self.default}' if (self.default is not None) else '')) | |