How to access URL params in the redirected URL

Hello, I use a very Javascript line, but this is just for testing.

const code window.location.href.split("=").pop()

To find a good implementation, I think checking the Amplify JS repository help HERE. More specifically, clone the code and read this two files Auth.ts and OAuth.ts

	private async _handleCodeFlow(currentUrl: string) {
		/* Convert URL into an object with parameters as keys
    { redirect_uri: 'http://localhost:3000/', response_type: 'code', ...} */
		const { code } = (parse(currentUrl).query || '')
			.split('&')
			.map(pairings => pairings.split('='))
			.reduce((accum, [k, v]) => ({ ...accum, [k]: v }), { code: undefined });

		const currentUrlPathname = parse(currentUrl).pathname || '/';
		const redirectSignInPathname =
			parse(this._config.redirectSignIn).pathname || '/';

		if (!code || currentUrlPathname !== redirectSignInPathname) {
			return;
		}

		const oAuthTokenEndpoint =
			'https://' + this._config.domain + '/oauth2/token';

		dispatchAuthEvent(
			'codeFlow',
			{},
			`Retrieving tokens from ${oAuthTokenEndpoint}`
		);

		const client_id = isCognitoHostedOpts(this._config)
			? this._cognitoClientId
			: this._config.clientID;

		const redirect_uri = isCognitoHostedOpts(this._config)
			? this._config.redirectSignIn
			: this._config.redirectUri;

		const code_verifier = oAuthStorage.getPKCE();

		const oAuthTokenBody = {
			grant_type: 'authorization_code',
			code,
			client_id,
			redirect_uri,
			...(code_verifier ? { code_verifier } : {}),
		};

		logger.debug(
			`Calling token endpoint: ${oAuthTokenEndpoint} with`,
			oAuthTokenBody
		);

		const body = Object.entries(oAuthTokenBody)
			.map(([k, v]) => `${encodeURIComponent(k)}=${encodeURIComponent(v)}`)
			.join('&');

		const { access_token, refresh_token, id_token, error } = await (
			(await fetch(oAuthTokenEndpoint, {
				method: 'POST',
				headers: {
					'Content-Type': 'application/x-www-form-urlencoded',
				},
				body,
			})) as any
		).json();

		if (error) {
			throw new Error(error);
		}

		return {
			accessToken: access_token,
			refreshToken: refresh_token,
			idToken: id_token,
		};
	}

Hi guys,

I just found this code at Internet that maybe has a possible solution:

const getIdToken = () => { const modifiedUrl = window.location.href.replace("#", "?") const url = new URL(modifiedUrl)

return url.searchParams.get("id_token") }

const idToken = getIdToken()

How do you think about, at least it's possible approach with Javascript !

Hello,

Thank you for reaching out to AWS Support. I am Arpit from Deployment Team, and I have taken the ownership of the case forward.

I understand that you would like to access parameters from the redirected URL.

Looking into this, I found one stack overflow article regarding accessing the URL parameters. https://stackoverflow.com/questions/63650885/how-to-get-query-data-from-redirected-url

Can you please look into this, and check if the above fulfills your use-case.

Further, since code support is out of AWS Premium Support, and due to limited expertise with Javascript, we can assist you on best effort basis.

Hoping that the above helps.

Hi hai,

Thanks for your reply. The code above it's interesting, but as I see, we need to pass the URL to the _handleCodeFlow method, but what I mean is how to recover the URL from the redirection, as you told with a inline example with Javascript, maybe this would be a soluction for my problem, anyway I've searching a few solutions, and I found some examples, but I'm not sure. One example would be recover the URL from the fetch petition to the Hosted UI in the response object, I've seen that this request obtain a response and in the response there is an object called "location" with the complet URL inside, but I'll not check yet. Any other sugestion will be welcome. Have your more ideas ? thanks in advance !

Have a nice day ahead.

Hi guys,

Thanks a lot for your help. I've checked the stackoverflow URL and it's more interesting. Now I'm wondering if when the hoster UI of Cognito redirects to the URL configured as redirect URL, maybe can we access to the response object of the corresponding request ? although of the redirection ?, I suppose when the redirect occurs we should have access to this object. What do you think about !

Thanks and have a nice day ahead.