Render a Solidity view / pure function call as a typed form: function
name header, one AbiInput per argument, a "Read"
button, and a result panel that pattern-matches on the current Status.
Like every primitive in this lib, the component is stateless -- the
caller owns the args (one AbiInput.Config per argument) and the
status and passes them in on every render. The lib renders, the caller
wires the result back through update.
Pair with Web3.Contract.Call
to actually fire the read:
-- in update
Read fn ->
( { model | reads = Dict.insert fn Pending model.reads }
, web3Cmd
(Call.encode
(Call.readCall
{ contract = tokenAddress
, method = "balanceOf(address)"
, args = [ resolvedArg ]
, decoder = Decode.uint256
, id = fn
}
)
)
)
-- in view
Web3.Ui.ContractRead.view []
{ name = "balanceOf"
, solType = "uint256"
, args = [ holderArgConfig ]
, status = Maybe.withDefault Idle (Dict.get "balanceOf" model.reads)
, onRead = Read "balanceOf"
, readLabel = "Read"
}CSS classes: web3-contract-read, web3-contract-read__header,
web3-contract-read__name, web3-contract-read__return-type,
web3-contract-read__args, web3-contract-read__button,
web3-contract-read__pending, web3-contract-read__result,
web3-contract-read__result--success, web3-contract-read__result--failed.
Configuration for view.
name -- the function name to display (e.g. "balanceOf").solType -- the return type string for display (e.g. "uint256").args -- one AbiInput config per ABI argument.status -- current lifecycle state.onRead -- message dispatched when the user clicks the read button.readLabel -- button label when idle / terminal (e.g. "Read" or "Refresh").Lifecycle of a single read.
Success String carries the rendered result -- the caller stringifies the
typed value (using whatever Web3.Abi.Decode-produced value they decoded).
This keeps ContractRead agnostic to the result type.
True for Success _ and Failed _.
Render the read form.