cerc-io/solidity
16
0
Fork 0
mirror of https://github.com/ethereum/solidity synced 2023-10-03 13:03:40 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Clarify documentation about events (mostly topics).

Browse Source
This commit is contained in:
chriseth 2018-06-04 19:29:51 +02:00 committed by Alex Beregszaszi
parent 4189b6b03d
commit 3eebba1087
1 changed files with 8 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
docs/contracts.rst
View File

@ -723,22 +723,18 @@ the contract can only see the last 256 block hashes.
Up to three parameters can Up to three parameters can
receive the attribute ``indexed`` which will cause the respective arguments receive the attribute ``indexed`` which will cause the respective arguments
to be searched for: It is possible to filter for specific values of to be stored in a special data structure as so-called "topics", which allows them to be searched for,
indexed arguments in the user interface. for example when filtering a sequence of blocks for certain events. Events can always
be filtered by the address of the contract that emitted the event. Also,
If arrays (including ``string`` and ``bytes``) are used as indexed arguments, the the hash of the signature of the event is one of the topics except if you
Keccak-256 hash of it is stored as topic instead.
The hash of the signature of the event is one of the topics except if you
declared the event with ``anonymous`` specifier. This means that it is declared the event with ``anonymous`` specifier. This means that it is
not possible to filter for specific anonymous events by name. not possible to filter for specific anonymous events by name.
All non-indexed arguments will be stored in the data part of the log. If arrays (including ``string`` and ``bytes``) are used as indexed arguments, the
Keccak-256 hash of it is stored as topic instead. This is because a topic
can only hold a single word (32 bytes).
.. note:: All non-indexed arguments will be :ref:`ABI-encoded <ABI>` into the data part of the log.
Indexed arguments will not be stored themselves. You can only
search for the values, but it is impossible to retrieve the
values themselves.
:: ::