Injected Interface Design

[Zergity]

We need an injected interface design so dapps can interact with browser extension wallets (MathWallet, eDeFi, etc.)

Goals:

• Dapp should work with any browser extension, without knowing which is installed on the user browser.
• It's a plus if dapp knows the name of the browser extension, but just for display, not functionality.

Ethereum dapps rely on a single injection point (window.ethereum) for wallet interaction. All wallet extensions (MetaMask, ezDeFi, etc.) must compete for the chance to get injected since there's only 1 extension is active at a time. This is very simple for dapp to use but dapp also doesn't know which wallet is used (for display).

Solution 1: single interface - single wallet (same with Ethereum with extra info)

• Dapp uses the same window.solana for all wallet extensions. The name of the wallet can be queried in window.solana.name and window.solana.desc, but they're optional for both dapp and wallets.
• Dapp UI will show only 1 entry for the injected wallet (since there's only 1 can active at a time), the name of the wallet can be queried from window.solana.name or just injected.

Solution 2: single interface - multiple wallets

• Wallets inject into window.solana[walletname], and dapps can use any of the wallets in the array they preferred, using the same interface as the current window.solana. Or just select the first one if they don't care.
• Dapp UI will show each wallet as an entry, and multiple wallets can be installed together.

Solution 3: single dispatcher - multiple wallets

• window.solana is injected to be a dispatcher, so it can be used just like window.ethereum
• window.solana.wallet[name] is injected by each extensions.
• window.solana.selectWallet(name) tells the dispatcher to redirect all requests to window.solana.wallets[name]. If none is set, the first wallet will be used.
• window.solana.getWallets() returns all injected wallets.

Please discuss.

Related PRs: #11 #8

[ericfish]

Some thoughts about this:

1. Solution 1 is used in other blockchain such as Ethereum/Polkadot, so far there is not big complains from the user side.
2. Finally it is still the user's choice, no matter the user choice the wallet from dapp front-end or user choice which browser extension to use. But solution 2 need more understanding and effort from dapp team side which may cause confusion.
3. This conflict does not exist in mobile app wallet since each app has its own injection environment. But solution 2 need more understanding and effort from dapp team side to support different mobile wallet as well which may cause confusion.

[Zergity]

But solution 2 need more understanding and effort from dapp team side which may cause confusion.

Good point. I have added Solution 3 to address this.

[ericfish]

Solution 3 is better, but all inject wallets need to follow the rules:

1. Do not overwrite window.solana, always check if this object exist or not
2. Use different name

[Zergity]

I've updated #11 so the provider object can be passed directly to the constructor, so it works with any of the solutions above. Dapp code can use new Wallet('solet.io') or new Wallet(window.solana) or new Wallet(window.anything) as long as it's injected.

[Civoremo]

Been trying to use solflare extension wallet and receive error saying "provider parameter must be an injected provider or a URL string" when doing new Wallet(window.solflare). any hints on whats causing the issue? phantom and sollet work without issues, for coin98 wallet had to build a wrapper for it to work