Support customisation of supported protocols

[realityfilter]

Is your feature request related to a problem? Please describe.

Since version 0.27.0 the supported protocols are a fixed set specified in platform.

axios/lib/platform/browser/index.js

Line 42 in cd8989a

protocols: ['http', 'https', 'file', 'blob', 'url', 'data']

We are using axios in a capacitor app that uses the special capacitor protocol.

Describe the solution you'd like

We need an option to specify additional supported protocols.

Describe alternatives you've considered

Use version 0.26.2 as a workaround.

[WillianAgostini]

Hi @realityfilter,
Adding a new parameter useProtocol in axios.create or in axios.[get,post,put...]

// Set config defaults when creating the instance
const instance = axios.create({
  baseURL: 'https://api.example.com',
  useProtocol: 'my-protocol'
});

axios.post('/user/12345', {
  name: 'new name'
}, {
  useProtocol: 'my-protocol'
})

that overrides the default protocol on the platform can resolve this issue?

If it's Ok I can create a PR.

[realityfilter]

Thank you very much for the effort. For me the naming is a bit misleading.

Currently requests with 'capacitor://' protocol are leading to exceptions because of 'capacitor' is not in the fixed set of protocols for the platform. I would like to register additional valid protocols either in the instance or per request.

The name useProtocol is suggesting, that requests not specifying a protocol should use this one. That is not the intention.

const instance = axios.create({
  baseURL: 'https://api.example.com',
  registerProtocols: ['capacitor', 'custom']
});

axios.post('/user/12345', {
  name: 'new name'
}, {
    registerProtocols: ['capacitor', 'custom']
})

This is because we might have no need for a global axios instance and we target urls with different protocols.

[WillianAgostini]

Axios uses url lib to parse an URL, so I can pass protocol by default from the url base, here is an example. Look at tag protocol.

> url.parse('https://stackoverflow.com/questions/36588396/node-js-url-parsing');
Url {
  protocol: 'https:',
  slashes: true,
  auth: null,
  host: 'stackoverflow.com',
  port: null,
  hostname: 'stackoverflow.com',
  hash: null,
  search: null,
  query: null,
  pathname: '/questions/36588396/node-js-url-parsing',
  path: '/questions/36588396/node-js-url-parsing',
  href: 'https://stackoverflow.com/questions/36588396/node-js-url-parsing'
}
> const url = require('url');
> url.parse('capacitor://stackoverflow.com/');
Url {
  protocol: 'capacitor:',
  slashes: true,
  auth: null,
  host: 'stackoverflow.com',
  port: null,
  hostname: 'stackoverflow.com',
  hash: null,
  search: null,
  query: null,
  pathname: '/',
  path: '/',
  href: 'capacitor://stackoverflow.com/'
}

It resolves this issue or should we proceed to add a new feature?

[realityfilter]

This is the problematic section:

axios/lib/adapters/xhr.js

Lines 240 to 245 in cd8989a

	const protocol = parseProtocol(fullPath);
	if (protocol && platform.protocols.indexOf(protocol) === -1) {
	reject(new AxiosError('Unsupported protocol ' + protocol + ':', AxiosError.ERR_BAD_REQUEST, config));
	return;
	}

The changelog states:

Version 0.27.1:

• Removed import of url module in browser build due to huge size overhead and builds being broken (Removed import of url module in browser build due to huge size overhead… #4594)

So I think it is better to add a new feature?

[WillianAgostini]

It's a better idea to add a new feature, adding registerProtocols in platform.protocols.
Will be provided 3 ways to configure registerProtocols:

Creating an instance

const instance = axios.create({
  baseURL: 'https://api.example.com',
  registerProtocols: ['capacitor', 'custom']
});

Instance methods

axios.post('/user/12345', {
  name: 'new name'
}, {
    registerProtocols: ['capacitor', 'custom']
})

Global axios defaults

axios.defaults.registerProtocols: ['capacitor', 'custom']

I'll make the changes to this feature.

[realityfilter]

That is exactly what is needed. Thank you very much.

[WillianAgostini]

@realityfilter, There's some example that I can use to test with the client and server that can reproduce the issue #4901 (comment)?

[realityfilter]

describe('axios', () => {
    it('should know protocol capacitor', async () => {
        try {
            await axios.get('capacitor://localhost/test.js')
        } catch (e) {
            console.log(e)
            expect(e.code).not.toBe('ERR_BAD_REQUEST')
            expect(e.message).not.toBe('Unsupported protocol capacitor:')
        }
    })
})

[WillianAgostini]

Has a limitation on one of the libraries used by axios.

On line https://github.com/WillianAgostini/axios/blob/871ef051124fa9f02dcc05c67f29ff9ce3e681b5/lib/adapters/http.js#L292 has a call to lib follow-redirects, but she has a limitation to use only https or http connection https://github.com/follow-redirects/follow-redirects/blob/main/index.js#L597.

[realityfilter]

That would be no problem in this use case.

[honungsburk]

I have a use case that requires handling custom protocols and redirect. The SIOPv2 spec uses redirects with openid://... for same-device communication (this allows smartphones to open the correct app). In my case, I'm writing a simple CLI tool and need to deal with the redirect myself.

Right now I solved it by simply setting maxRedirects to 0 and then catching the error

Simple example:

  let reqURI = "";
  await axios
    .post(path, undefined, {
      maxRedirects: 0,
    })
    .catch((err) => {
      if (err.response.status === 302) {
        // We should have been redirected to "openid://?response_type=id_token..."
        reqURI = err.response.headers.location;
      } else {
        throw err;
      }
    });

I don't need any features to be added (I think at least) but I thought you guys should know the use case exists.

[dhondtlaurens]

@WillianAgostini, Is there a PR already? Or can we help with something to add this feature? I'm having the same issue with a custom protocol on android devices and I found the rules @realityfilter posted to be responsible:

axios/lib/adapters/xhr.js

Lines 240 to 245 in cd8989a

	const protocol = parseProtocol(fullPath);
	if (protocol && platform.protocols.indexOf(protocol) === -1) {
	reject(new AxiosError('Unsupported protocol ' + protocol + ':', AxiosError.ERR_BAD_REQUEST, config));
	return;
	}

Thanks in advance!

[WillianAgostini]

Hi @dhondtlaurens
I committed WillianAgostini@2d7277e to customize protocols on xhr adapter.
But it is still missing a test case for this feature, with a server that supports the "capacitor" protocol to respond.

[dhondtlaurens]

Any reason why the test case of @realityfilter is not enough? Because this is not a capacitor-specific problem. All requests with a different URL scheme (protocol) are impacted, so the test should only check the following things:

• 1. When registerProtocols is not set, expect the error to be ERR_BAD_REQUEST + Unsupported protocol xxx
• 2. When registerProtocols is set, expect the error not to be ERR_BAD REQUEST + Unsupported protocol xxx

Any thoughts on this?

[exander77]

Does this work? I have a custom protocol after redirect.

I also think maxRedidirects: n is broken. In my opinion it should do at most n redirects, not issue error, when there are more redirects available.

[exander77]

I am looking into beforeRedirect, but is not clear if I can cancel redirect there?

[sebastienlabine]

I truly don't think register protocol is the way. We should be able to handle any valid protocol, like @honungsburk 's use case.

[exander77]

I truly don't think register protocol is the way. We should be able to handle any valid protocol, like @honungsburk 's use case.

Issue is that any protocol is valid.

[alevys]

Hi! Are there any movements on this issue? It is very necessary to use a custom protocol, like - vkcors://, but not with new versions. You have to use only the old version 0.26.1, which still has support for custom protocols. Please add the ability to use custom protocols. Thank you.

[Space1nvader]

Hi! Are there any movements on this issue? It is very necessary to use a custom protocol, like - vkcors://, but not with new versions. You have to use only the old version 0.26.1, which still has support for custom protocols. Please add the ability to use custom protocols. Thank you.

Thank you very match for your solution

[alevys]

Hello! Are there any changes planned on this issue? Thank you.

[andrewgul]

@alevys Hello! Maybe you found some alternative solution?