`AbiEvent`

Zig representation of the ABI Event

const zabi = @import("zabi");
 
const Abi = zabi.abi.Event;
 
// Internal representation
const Event = struct {
    type: Extract(Abitype, "event"),
    inputs: []const AbiParameter,
    name: []const u8,
    anonymous: ?bool = null,
}

This type also includes methods that can be used for formatting/encoding.

Prepare

This method converts the struct signature into a human readable format that is ready to be hash. This is intended to be used with a Writer

This takes in 1 arguments:

any writer from the std or custom writer.

const std = @import("std");
const Event = @import("zabi").abi.Event;
 
const abi_event: Event = .{
  .type = .event, 
  .name = "Foo", 
  .inputs = &.{
      .{ .type = .{ .bool = {} }, .name = "foo"}, 
      .{ .type = .{ .string = {} }, .name = "bar" } 
//^?
    },
};
 
const writer = std.io.getStdOut().writer();
 
try self.prepare(&writer);
 
// Result
// Foo(bool foo, string bar)

Returns

Type: void

AllocPrepare

Same exact method the difference is that it takes an allocator and returns the encoded string.

This takes in 2 arguments:

an allocator used to manage the memory allocations
any writer from the std or custom writer.

Memory must be freed after calling this method.

const std = @import("std");
const Event = @import("zabi").abi.Event;
 
const abi_event: Event = .{
  .type = .event, 
  .name = "Foo", 
  .inputs = &.{
      .{ .type = .{ .bool = {} }, .name = "foo"}, 
      .{ .type = .{ .string = {} }, .name = "bar" } 
    },
};
 
const writer = std.io.getStdOut().writer();
 
try self.allocPrepare(std.testing.allocator, &writer);
 
// Result
// Foo(bool foo, string bar)

Returns

Type: []u8

Encode Inputs

Generates Abi encoded data using the contract ABI specification by a given set of inputs and the associated values.

Current we don't support encoding the values. But expect this to change in a future release.

This takes in 1 arguments:

an allocator used to manage the memory allocations

Memory must be freed after calling this method.

const std = @import("std");
const Event = @import("zabi").abi.Event;
 
const abi_event: Event = .{
  .type = .event, 
  .name = "Transfer", 
  .inputs = &.{
      .{ .type = .{ .address = {} }, .name = "from", .indexed = true}, 
      .{ .type = .{ .address = {} }, .name = "to", .indexed = true},
      .{ .type = .{ .uint = 256 }, .name = "tokenId", .indexed = false},
    },
};
 
const encoded = try abi_event.encode(std.testing.allocator);
 
// Result
// ddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef

Returns

Type: []u8 -> The hex encoded event signature.

Format

Format the event struct signature into a human readable format. This is a custom format method that will override all call from the std to format methods

const std = @import("std");
const Event = @import("zabi").abi.Event;
 
const abi_event: Event = .{
  .type = .event, 
  .name = "Foo", 
  .inputs = &.{
      .{ .type = .{ .bool = {} }, .name = "foo"}, 
      .{ .type = .{ .string = {} }, .name = "bar" } 
    },
};
 
std.debug.print("{s}", .{abi_event});
 
// Outputs
// event Foo(bool foo, string bar)

Returns

Type: void