method

findProxyFromEnvironment

Source

/**
 * Function for resolving the proxy server to be used for a HTTP
 * connection from the proxy configuration specified through
 * environment variables.
 *
 * The following environment variables are taken into account:
 *
 *     http_proxy
 *     https_proxy
 *     no_proxy
 *     HTTP_PROXY
 *     HTTPS_PROXY
 *     NO_PROXY
 *
 * [:http_proxy:] and [:HTTP_PROXY:] specify the proxy server to use for
 * http:// urls. Use the format [:hostname:port:]. If no port is used a
 * default of 1080 will be used. If both are set the lower case one takes
 * precedence.
 *
 * [:https_proxy:] and [:HTTPS_PROXY:] specify the proxy server to use for
 * https:// urls. Use the format [:hostname:port:]. If no port is used a
 * default of 1080 will be used. If both are set the lower case one takes
 * precedence.
 *
 * [:no_proxy:] and [:NO_PROXY:] specify a comma separated list of
 * postfixes of hostnames for which not to use the proxy
 * server. E.g. the value "localhost,127.0.0.1" will make requests
 * to both "localhost" and "127.0.0.1" not use a proxy. If both are set
 * the lower case one takes precedence.
 *
 * To activate this way of resolving proxies assign this function to
 * the [findProxy] property on the [HttpClient].
 *
 *     HttpClient client = new HttpClient();
 *     client.findProxy = HttpClient.findProxyFromEnvironment;
 *
 * If you don't want to use the system environment you can use a
 * different one by wrapping the function.
 *
 *     HttpClient client = new HttpClient();
 *     client.findProxy = (url) {
 *       return HttpClient.findProxyFromEnvironment(
 *           url, {"http_proxy": ..., "no_proxy": ...});
 *     }
 *
 * If a proxy requires authentication it is possible to configure
 * the username and password as well. Use the format
 * [:username:password@hostname:port:] to include the username and
 * password. Alternatively the API [addProxyCredentials] can be used
 * to set credentials for proxies which require authentication.
 */
static String findProxyFromEnvironment(Uri url,
                                       {Map<String, String> environment}) {
  return _HttpClient._findProxyFromEnvironment(url, environment);
}