File size: 17,273 Bytes
d1ceb73 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 |
"""Process URI templates per http://tools.ietf.org/html/rfc6570."""
from __future__ import annotations
import collections
from typing import Any, TYPE_CHECKING, cast
from .charset import Charset
from .variable import Variable
if (TYPE_CHECKING):
from collections.abc import Iterable, Mapping
class ExpansionFailedError(Exception):
"""Exception thrown when expansions fail."""
variable: str
def __init__(self, variable: str) -> None:
self.variable = variable
def __str__(self) -> str:
"""Convert to string."""
return 'Bad expansion: ' + self.variable
class Expansion:
"""
Base class for template expansions.
https://tools.ietf.org/html/rfc6570#section-3
"""
def __init__(self) -> None:
pass
@property
def variables(self) -> Iterable[Variable]:
"""Get all variables in this expansion."""
return []
@property
def variable_names(self) -> Iterable[str]:
"""Get the names of all variables in this expansion."""
return []
def _encode(self, value: str, legal: str, pct_encoded: bool) -> str:
"""Encode a string into legal values."""
output = ''
index = 0
while (index < len(value)):
codepoint = value[index]
if (codepoint in legal):
output += codepoint
elif (pct_encoded and ('%' == codepoint)
and ((index + 2) < len(value))
and (value[index + 1] in Charset.HEX_DIGIT)
and (value[index + 2] in Charset.HEX_DIGIT)):
output += value[index:index + 3]
index += 2
else:
utf8 = codepoint.encode('utf8')
for byte in utf8:
output += '%' + Charset.HEX_DIGIT[int(byte / 16)] + Charset.HEX_DIGIT[byte % 16]
index += 1
return output
def _uri_encode_value(self, value: str) -> str:
"""Encode a value into uri encoding."""
return self._encode(value, Charset.UNRESERVED, False)
def _uri_encode_name(self, name: (str | int)) -> str:
"""Encode a variable name into uri encoding."""
return self._encode(str(name), Charset.UNRESERVED + Charset.RESERVED, True) if (name) else ''
def _join(self, prefix: str, joiner: str, value: str) -> str:
"""Join a prefix to a value."""
if (prefix):
return prefix + joiner + value
return value
def _encode_str(self, variable: Variable, name: str, value: str, prefix: str, joiner: str, first: bool) -> str:
"""Encode a string value for a variable."""
if (variable.max_length):
if (not first):
raise ExpansionFailedError(str(variable))
return self._join(prefix, joiner, self._uri_encode_value(value[:variable.max_length]))
return self._join(prefix, joiner, self._uri_encode_value(value))
def _encode_dict_item(self, variable: Variable, name: str, key: (int | str), item: Any,
delim: str, prefix: str, joiner: str, first: bool) -> (str | None):
"""Encode a dict item for a variable."""
joiner = '=' if (variable.explode) else ','
if (variable.array):
name = self._uri_encode_name(key)
prefix = (prefix + '[' + name + ']') if (prefix and not first) else name
else:
prefix = self._join(prefix, '.', self._uri_encode_name(key))
return self._encode_var(variable, str(key), item, delim, prefix, joiner, False)
def _encode_list_item(self, variable: Variable, name: str, index: int, item: Any,
delim: str, prefix: str, joiner: str, first: bool) -> (str | None):
"""Encode a list item for a variable."""
if (variable.array):
prefix = prefix + '[' + str(index) + ']' if (prefix) else ''
return self._encode_var(variable, '', item, delim, prefix, joiner, False)
return self._encode_var(variable, name, item, delim, prefix, '.', False)
def _encode_var(self, variable: Variable, name: str, value: Any,
delim: str = ',', prefix: str = '', joiner: str = '=', first: bool = True) -> (str | None):
"""Encode a variable."""
if (isinstance(value, str)):
return self._encode_str(variable, name, value, prefix, joiner, first)
elif (isinstance(value, collections.abc.Mapping)):
if (len(value)):
encoded_items = [self._encode_dict_item(variable, name, key, value[key], delim, prefix, joiner, first)
for key in value.keys()]
return delim.join([item for item in encoded_items if (item is not None)])
return None
elif (isinstance(value, collections.abc.Sequence)):
if (len(value)):
encoded_items = [self._encode_list_item(variable, name, index, item, delim, prefix, joiner, first)
for index, item in enumerate(value)]
return delim.join([item for item in encoded_items if (item is not None)])
return None
elif (isinstance(value, bool)):
return self._encode_str(variable, name, str(value).lower(), prefix, joiner, first)
else:
return self._encode_str(variable, name, str(value), prefix, joiner, first)
def expand(self, values: Mapping[str, Any]) -> (str | None):
"""Expand values."""
return None
def partial(self, values: Mapping[str, Any]) -> str:
"""Perform partial expansion."""
return ''
class Literal(Expansion):
"""
A literal expansion.
https://tools.ietf.org/html/rfc6570#section-3.1
"""
value: str
def __init__(self, value: str) -> None:
super().__init__()
self.value = value
def expand(self, values: Mapping[str, Any]) -> (str | None):
"""Perform exansion."""
return self._encode(self.value, (Charset.UNRESERVED + Charset.RESERVED), True)
def __str__(self) -> str:
"""Convert to string."""
return self.value
class ExpressionExpansion(Expansion):
"""
Base class for expression expansions.
https://tools.ietf.org/html/rfc6570#section-3.2
"""
operator = ''
partial_operator = ','
output_prefix = ''
var_joiner = ','
partial_joiner = ','
vars: list[Variable]
trailing_joiner: str = ''
def __init__(self, variables: str) -> None:
super().__init__()
if (variables and (variables[-1] in (',', '.', '/', ';', '&'))):
self.trailing_joiner = variables[-1]
variables = variables[:-1]
self.vars = [Variable(var) for var in variables.split(',')]
@property
def variables(self) -> Iterable[Variable]:
"""Get all variables."""
return list(self.vars)
@property
def variable_names(self) -> Iterable[str]:
"""Get names of all variables."""
return [var.name for var in self.vars]
def _expand_var(self, variable: Variable, value: Any) -> (str | None):
"""Expand a single variable."""
return self._encode_var(variable, self._uri_encode_name(variable.name), value)
def expand(self, values: Mapping[str, Any]) -> (str | None):
"""Expand all variables, skip missing values."""
expanded_vars: list[str] = []
for var in self.vars:
value = values.get(var.key, var.default)
if (value is not None):
expanded_var = self._expand_var(var, value)
if (expanded_var is not None):
expanded_vars.append(expanded_var)
if (expanded_vars):
return ((self.output_prefix if (not self.trailing_joiner) else '') + self.var_joiner.join(expanded_vars)
+ self.trailing_joiner)
return None
def partial(self, values: Mapping[str, Any]) -> str:
"""Expand all variables, replace missing values with expansions."""
expanded_vars: list[str] = []
missing_vars: list[Variable] = []
result: list[tuple[(list[str] | None), (list[Variable] | None)]] = []
for var in self.vars:
value = values.get(var.name, var.default)
if (value is not None):
expanded_var = self._expand_var(var, value)
if (expanded_var is not None):
if (missing_vars):
result.append((None, missing_vars))
missing_vars = []
expanded_vars.append(expanded_var)
else:
if (expanded_vars):
result.append((expanded_vars, None))
expanded_vars = []
missing_vars.append(var)
if (expanded_vars):
result.append((expanded_vars, None))
if (missing_vars):
result.append((None, missing_vars))
output: str = ''
first = True
for index, (expanded, missing) in enumerate(result):
last = (index == (len(result) - 1))
if (expanded):
output += ((self.output_prefix if (first and (not self.trailing_joiner)) else '')
+ self.var_joiner.join(expanded) + self.trailing_joiner)
else:
output += ((self.output_prefix if (first and not last) else (self.var_joiner if (not last) else ''))
+ '{' + (self.operator if (first) else self.partial_operator)
+ ','.join([str(var) for var in cast('list[Variable]', missing)])
+ (self.partial_joiner if (not last) else '') + '}')
first = False
return output
def __str__(self) -> str:
"""Convert to string."""
return ('{' + self.operator + ','.join([str(var) for var in self.vars]) + self.trailing_joiner + '}')
class SimpleExpansion(ExpressionExpansion):
"""
Simple String expansion {var}.
https://tools.ietf.org/html/rfc6570#section-3.2.2
"""
def __init__(self, variables: str) -> None:
super().__init__(variables)
class ReservedExpansion(ExpressionExpansion):
"""
Reserved Expansion {+var}.
https://tools.ietf.org/html/rfc6570#section-3.2.3
"""
operator = '+'
partial_operator = ',+'
def __init__(self, variables: str) -> None:
super().__init__(variables[1:])
def _uri_encode_value(self, value: str) -> str:
"""Encode a value into uri encoding."""
return self._encode(value, (Charset.UNRESERVED + Charset.RESERVED), True)
class FragmentExpansion(ReservedExpansion):
"""
Fragment Expansion {#var}.
https://tools.ietf.org/html/rfc6570#section-3.2.4
"""
operator = '#'
output_prefix = '#'
def __init__(self, variables: str) -> None:
super().__init__(variables)
class LabelExpansion(ExpressionExpansion):
"""
Label Expansion with Dot-Prefix {.var}.
https://tools.ietf.org/html/rfc6570#section-3.2.5
"""
operator = '.'
partial_operator = '.'
output_prefix = '.'
var_joiner = '.'
partial_joiner = '.'
def __init__(self, variables: str) -> None:
super().__init__(variables[1:])
def _expand_var(self, variable: Variable, value: Any) -> (str | None):
"""Expand a single variable."""
return self._encode_var(variable, self._uri_encode_name(variable.name), value,
delim=('.' if variable.explode else ','))
class PathExpansion(ExpressionExpansion):
"""
Path Segment Expansion {/var}.
https://tools.ietf.org/html/rfc6570#section-3.2.6
"""
operator = '/'
partial_operator = '/'
output_prefix = '/'
var_joiner = '/'
partial_joiner = '/'
def __init__(self, variables: str) -> None:
super().__init__(variables[1:])
def _expand_var(self, variable: Variable, value: Any) -> (str | None):
"""Expand a single variable."""
return self._encode_var(variable, self._uri_encode_name(variable.name), value,
delim=('/' if variable.explode else ','))
class PathStyleExpansion(ExpressionExpansion):
"""
Path-Style Parameter Expansion {;var}.
https://tools.ietf.org/html/rfc6570#section-3.2.7
"""
operator = ';'
partial_operator = ';'
output_prefix = ';'
var_joiner = ';'
partial_joiner = ';'
def __init__(self, variables: str) -> None:
super().__init__(variables[1:])
def _encode_str(self, variable: Variable, name: str, value: Any, prefix: str, joiner: str, first: bool) -> str:
"""Encode a string for a variable."""
if (variable.array):
if (name):
prefix = prefix + '[' + name + ']' if (prefix) else name
elif (variable.explode):
prefix = self._join(prefix, '.', name)
return super()._encode_str(variable, name, value, prefix, joiner, first)
def _encode_dict_item(self, variable: Variable, name: str, key: (int | str), item: Any,
delim: str, prefix: str, joiner: str, first: bool) -> (str | None):
"""Encode a dict item for a variable."""
if (variable.array):
if (name):
prefix = prefix + '[' + name + ']' if (prefix) else name
if (prefix and not first):
prefix = (prefix + '[' + self._uri_encode_name(key) + ']')
else:
prefix = self._uri_encode_name(key)
elif (variable.explode):
prefix = self._join(prefix, '.', name) if (not first) else ''
else:
prefix = self._join(prefix, '.', self._uri_encode_name(key))
joiner = ','
return self._encode_var(variable, self._uri_encode_name(key) if (not variable.array) else '', item,
delim, prefix, joiner, False)
def _encode_list_item(self, variable: Variable, name: str, index: int, item: Any,
delim: str, prefix: str, joiner: str, first: bool) -> (str | None):
"""Encode a list item for a variable."""
if (variable.array):
if (name):
prefix = prefix + '[' + name + ']' if (prefix) else name
return self._encode_var(variable, str(index), item, delim, prefix, joiner, False)
return self._encode_var(variable, name, item, delim, prefix, '=' if (variable.explode) else '.', False)
def _expand_var(self, variable: Variable, value: Any) -> (str | None):
"""Expand a single variable."""
if (variable.explode):
return self._encode_var(variable, self._uri_encode_name(variable.name), value, delim=';')
value = self._encode_var(variable, self._uri_encode_name(variable.name), value, delim=',')
return (self._uri_encode_name(variable.name) + '=' + value) if (value) else variable.name
class FormStyleQueryExpansion(PathStyleExpansion):
"""
Form-Style Query Expansion {?var}.
https://tools.ietf.org/html/rfc6570#section-3.2.8
"""
operator = '?'
partial_operator = '&'
output_prefix = '?'
var_joiner = '&'
partial_joiner = '&'
def __init__(self, variables: str) -> None:
super().__init__(variables)
def _expand_var(self, variable: Variable, value: Any) -> (str | None):
"""Expand a single variable."""
if (variable.explode):
return self._encode_var(variable, self._uri_encode_name(variable.name), value, delim='&')
value = self._encode_var(variable, self._uri_encode_name(variable.name), value, delim=',')
return (self._uri_encode_name(variable.name) + '=' + value) if (value is not None) else None
class FormStyleQueryContinuation(FormStyleQueryExpansion):
"""
Form-Style Query Continuation {&var}.
https://tools.ietf.org/html/rfc6570#section-3.2.9
"""
operator = '&'
output_prefix = '&'
def __init__(self, variables: str) -> None:
super().__init__(variables)
# non-standard extension
class CommaExpansion(ExpressionExpansion):
"""
Label Expansion with Comma-Prefix {,var}.
Non-standard extension to support partial expansions.
"""
operator = ','
output_prefix = ','
def __init__(self, variables: str) -> None:
super().__init__(variables[1:])
def _expand_var(self, variable: Variable, value: Any) -> (str | None):
"""Expand a single variable."""
return self._encode_var(variable, self._uri_encode_name(variable.name), value,
delim=('.' if variable.explode else ','))
class ReservedCommaExpansion(ReservedExpansion):
"""
Reserved Expansion with comma prefix {,+var}.
Non-standard extension to support partial expansions.
"""
operator = ',+'
output_prefix = ','
def __init__(self, variables: str) -> None:
super().__init__(variables[1:])
def _expand_var(self, variable: Variable, value: Any) -> (str | None):
"""Expand a single variable."""
return self._encode_var(variable, self._uri_encode_name(variable.name), value,
delim=('.' if variable.explode else ','))
|