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Specifications | Variables Specification

Variables Specification

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Variables can be used for nearly every monax jobs field (largely with the exception of nonce and wait).

Jobs variables will always begin with a dollar sign $. This is what will trigger the variable expansion.

Variables come in the following types:

Job Result Variable

The result of every job is set as a variable with the JobName as the key and the JobResult as the value. The JobResult for transaction jobs is the transaction hash. The JobResult for contract deployments is the address of the contract. The JobResult for queries and calls is the return value from the blockchain or the query.

The JobResults which are able to be retrieved from query functions will vary and depend largely on the fields which are returnable from monax-client's tooling.

Set Variables

Set variables will take the JobName and use the val field from the job file to set the variable.

Variable Types

If you're using solidity then you will be familiar with variable types. Here is how the package manager deals with variable types:

  • address - addresses should be given according to the 40 character string without the leading 0x
    • Example: 1040E6521541DAB4E7EE57F21226DD17CE9F0FB7
  • int && uint -- integers (signed and unsigned) should be given according to their plain text rendering of the digits
    • Example: 99999
  • bool - true or false
  • string and byteX -- just give it a string
    • Example: marmatoshi

For a more complete handling of the types, please see the epm.yaml in tests/jobs_fixtures/app06 directory of the repository.

Reserved Variables

The following are reserved variables:

  • $block: will return a string version of the current block height
  • $block+X: where X can be any digit; will return a string version of the current block height +X blocks
  • $block-X: where X can be any digit; will return a string version of the current block heigh -X blocks

Fallback Function

In order to test your fallback function in your contract using the call job, simply put the name of your function as "()" and the fallback function will be called. See tests/jobs_fixture/app37 in the monax repository.

Tuples and Returns

Jobs can now effectively handle multiple return values for all static types such as

  • address int uint bool bytes(1-32)

You can access these in your jobs by specifying the name of the value returned. If you have not appended a name to the value returned, simply call them by the order in which they are returned. For example:

contract tuples {
// for a job $getBools we could call this by
// $getBools.0 to get true and $getBools.1 to get false
    function getBools() returns (bool, bool) { return (true, false); }
// for a job $getInts here we would call $getInts.a == 3,$getInts.b == 5
    function getInts() returns (uint a, int b) { return (3, 5) }
}

for now, the package manager cannot handle dynamic types such as

  • string bytes struct

Hold with us while the marmots get those in control :)

Array Packing and Returns

Jobs can handle packing and returning of arrays with some caveats. In order to pack an array value in, you must declare it inside square brackets. For an example, see app31. Until then, you can declare arrays for most static types such as:

  • int uint bool bytes(1-32)

We currently do not handle packing of 2D arrays nor arrays of address, string, bytes, or struct. These are scheduled for upcoming releases.

All Specifications