Headers

20class Headers extends CaseInsensitiveDictionary {21	/**22	 * Get the given header23	 *24	 * Unlike {@see \WpOrg\Requests\Response\Headers::getValues()}, this returns a string. If there are25	 * multiple values, it concatenates them with a comma as per RFC2616.26	 *27	 * Avoid using this where commas may be used unquoted in values, such as28	 * Set-Cookie headers.29	 *30	 * @param string $offset Name of the header to retrieve.31	 * @return string|null Header value32	 */33	public function offsetGet($offset) {34		if (is_string($offset)) {35			$offset = strtolower($offset);36		}37 38		if (!isset($offset, $this->data[$offset])) {39			return null;40		}41 42		return $this->flatten($this->data[$offset]);43	}44 45	/**46	 * Set the given item47	 *48	 * @param string $offset Item name49	 * @param string $value Item value50	 *51	 * @throws \WpOrg\Requests\Exception On attempting to use dictionary as list (`invalidset`)52	 */53	public function offsetSet($offset, $value) {54		if ($offset === null) {55			throw new Exception('Object is a dictionary, not a list', 'invalidset');56		}57 58		if (is_string($offset)) {59			$offset = strtolower($offset);60		}61 62		if (!isset($this->data[$offset])) {63			$this->data[$offset] = [];64		}65 66		$this->data[$offset][] = $value;67	}68 69	/**70	 * Get all values for a given header71	 *72	 * @param string $offset Name of the header to retrieve.73	 * @return array|null Header values74	 *75	 * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed argument is not valid as an array key.76	 */77	public function getValues($offset) {78		if (!is_string($offset) && !is_int($offset)) {79			throw InvalidArgument::create(1, '$offset', 'string|int', gettype($offset));80		}81 82		if (is_string($offset)) {83			$offset = strtolower($offset);84		}85 86		if (!isset($this->data[$offset])) {87			return null;88		}89 90		return $this->data[$offset];91	}92 93	/**94	 * Flattens a value into a string95	 *96	 * Converts an array into a string by imploding values with a comma, as per97	 * RFC2616's rules for folding headers.98	 *99	 * @param string|array $value Value to flatten