add derives for transfer

[gregdhill]

Signed-off-by: Gregory Hill [email protected]

[lgtm-com]

This pull request introduces 1 alert when merging 203ce60 into 2eea385 - view on LGTM.com

new alerts:

• 1 for Unused variable, import, function or class

[lgtm-com]

This pull request introduces 1 alert when merging 75fa6ce into 2eea385 - view on LGTM.com

new alerts:

• 1 for Unused variable, import, function or class

[daniel-savu]

Even though there is a check for the api not to be undefined before calling this function, unless this if is added the app crashes

[jacogr]

The signature for all derives are -

// ReturnType is here for illustrative purposes
type ReturnType = string;

function myDerive (instanceId: string, api: ApiInterfaceRx): Observable<ReturnType> {
  return memo(instanceId, (): Observable<ReturnType> => {
    // we work with observables here
    return api.rpc.chain.getHeader().pipe(
      switchMap((header) => of(header.toString()))
    );    
  });
}

So in your case you received 2 params, not 3 (and not an ApiPromise instance, they don't exist in derives)

[daniel-savu]

Although the derive is defined in the apps-config for interBtc, it's empty when used here. transferBalance is what the derive is supposed to be, and it works this way. How can this be correctly implemented using the derive?

[daniel-savu]

@jacogr sorry for the tag, not sure if you get notifications from the comments above and I can't mark the PR from 'draft' to 'ready' myself.

Do you have any tips for fixing those two problems?

[nud3l]

@jacogr would be great to get your feedback on the two questions above. We'd like to resolve those to make it possible to transfer tokens that are implemented via orml-tokens.

[jacogr]

I did comment above, the TL;DR is that you need to use a derive interface with an ApiInterfaceRx signature to make it work.

[daniel-savu]

Thank you! I'll take a look as soon as I get a chance