Proxyable¶
Description¶
This contract is designed to operate in tandem with Proxy.
In fact, in order to function properly, every contract operating behind a CALL-style proxy must inherit Proxyable to ensure that the message sender is set and that events are correctly emitted.
This contract can support two proxies simultaneously. Events can be emitted independently from each proxy, but it is sensible to restrict event emission to a single proxy in most cases.
Source: contracts/Proxyable.sol
Variables¶
messageSender¶
The caller of the proxy in the current invocation. This variable is set to the value of msg.sender visible to the proxy before every function call by that Proxy to this Proxyable. Once set, messageSender should be used in place of msg.sender wherever it is used in contracts inheriting Proxyable.
All functions which make use of messageSender should have one of the modifiers provided by the Proxyable interface, otherwise users who call the contract directly rather than through the proxy will be executing with stale values of messageSender.
Functions which do not require messageSender need not apply any of the proxy modifiers, but care must be taken when applying other function modifiers within a proxyable contract. For example, see optionalProxy_onlyOwner.
Type: address
proxy¶
The address of the main proxy that this contract operates underneath. It is this address that events should be emitted from using Proxy._emit.
Type: contract Proxy
Constructor¶
constructor¶
Initialises this contract's proxy and the inherited Owned instance.
Details
Signature
constructor(address payable _proxy)
Visibility
internal
State Mutability
``
Requires
Emits
Restricted Functions¶
setMessageSender¶
This is used by proxies to set messageSender before forwarding a function call. This is only callable by the proxy or integrationProxy.
Details
Signature
setMessageSender(address sender)
Visibility
external
State Mutability
``
Modifiers
setProxy¶
Sets this contract's primary proxy. setProxy cannot be called through a proxy.
Details
Signature
setProxy(address payable _proxy)
Visibility
external
State Mutability
``
Modifiers
Emits
Modifiers¶
onlyProxy¶
Reverts the transaction if the actual msg.sender (not messageSender) is not the proxy or the integration proxy.
optionalProxy¶
This modifier allows a function to be called through the proxies, or alternatively to be called directly for a small gas savings.
It operates simply: if the caller is not either the proxy or the integration proxy, then overwrite messageSender with msg.sender, otherwise use whatever it was set to by the proxy.
optionalProxy_onlyOwner¶
This modifier is largely the same as optionalProxy, but it disallow callers who are not the contract owner. This modifier exists because Owned.onlyOwner checks msg.sender, and not messageSender.
Events¶
ProxyUpdated¶
proxyAddress has been set as the new proxy.
Signature: ProxyUpdated(address proxyAddress)