What's tezosgen

tezosgen is a smart contract code generator - you just specify the smart contract's specification and tezosgen generates type-safe .swift files, so using smart contracts in your iOS or Mac app has never been easier!

This project has been published as a part of Tezos-iOS-Dev-Kit

Installation

There are multiple possibilities to install tezosgen on your machine or in your project, depending on your preferences and needs. Note that if you do not install tezosgen using Cocoapods, you will have have to import TezosSwift by yourself.

Using Homebrew

$ brew tap AckeeCZ/tezosgen
$ brew install tezosgen
$ tezosgen

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Via CocoaPods

If you're using CocoaPods, you can simply add pod 'TezosGen' ~> 1.1.1 to your Podfile.

This will download the tezosgen binaries and dependencies in Pods/ during your next pod install execution.

Given that you can specify an exact version for tezosgen in your Podfile, this allows you to ensure all coworkers will use the same version of tezosgen for this project.

You can then invoke tezosgen from your terminal:

Pods/tezosgen/tezosgen …

Note: tezosgen isn't really a pod, as it's not a library your code will depend on at runtime; so the installation via CocoaPods is just a trick that installs the tezosgen binaries in the Pods/ folder, but you won't see any swift files in the Pods/tezosgen group in your Xcode's Pods.xcodeproj. That's normal: the tezosgen binary is still present in that folder in the Finder.

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Swift Package Manager

Add this to your Package.swift:

.package(url: "https://github.com/AckeeCZ/tezosgen.git", .upToNextMajor(from: "1.1.1")),

iOS MVVM Project Template

We have also created iOS MVVM Project Template, so setting your project has never been easier. Easily follow the installation instructions. After you are done, add name_of_your_abi.json file to Resources. Then add tezosgen to your Podfile, do pod install and run this command in your project root directory:

Pods/tezosgen/tezosgen HelloContract NameOfYourProject/Resources/abi.json -x NameOfYourProject.xcodeproj -o NameOfYourProject/Model/Generated/GeneraredContracts

Usage

Example

You can find an example app here.

How to Get Contract Specifcation

To be able to generate smart contract code, we first need to have its specification. To find it, simply run curl https://url_to_your_node/chains/main/blocks/head/context/contracts/contract_address | tr -d '\n'.

The output could look something like this:

{"manager":"tz1dD918PXDuUHV6Mh6z2QqMukA67YULuhqd","balance":"21000000","spendable":false,"delegate":{"setable":false},"script":{"code":[{"prim":"parameter","args":[{"prim":"set","args":[{"prim":"nat"}]}]},{"prim":"storage","args":[{"prim":"set","args":[{"prim":"nat"}]}]},{"prim":"code","args":[[{"prim":"CDR"},{"prim":"NIL","args":[{"prim":"operation"}]},{"prim":"PAIR"}]]}],"storage":[{"int":"1"},{"int":"2"},{"int":"3"}]},"counter":"0"}

What we need for our generator is hidden under the code key and we need to obtain the parameter and storage. So the specification for this contract, after a little modification, would look like this:

{"parameter": {"prim":"set","args":[{"prim":"nat"}]}, "storage": {"prim":"set","args":[{"prim":"nat"}]}}

To expand on this, the specification should look like this:

{"parameter": {code_specified_under_args_for_parameter}, "storage": {code_specified_under_args_for_parameter}

By defaul the parameters are then indexed from number one for better readability, but you can also name your parameters! (and if the values are named in the contract itself, you will get this for free). To do this, it would look like this: {"parameter": {"prim":"set", "annots":["%first"],"args":[{"prim":"nat"}]}, "storage": {"prim":"set","args":[{"prim":"nat"}]}}

(that is add to the type a new key-value pair "annots":["%desired_name"])

Codegen

The standard usage looks like this tezosgen HelloContract path_to_abi/abi.json -x path_to_xcodeproj/project.xcodeproj -o relative_output_path

Please note that the output path option (--output) should be relative to your project - if your generated files are in YourProjectName/MainFolder/GeneratedContracts folder, then you should write --output MainFolder/GeneratedContracts For your projects to be bound you also must set the --xcode option as well. Otherwise you will have to drag the files to your projects manually.

Combine

If you want to use the generated code with combine, just add this option when you are generating new code:

--extensions combine

Usage of Generated Codes

The standard call using code created by codegen looks like this:

import TezosSwift
tezosClient.optionalStringContract(at: "KT1Rh4iEMxBLJbDbz7iAB6FGLJ3mSCx3qFrW").call(param1: "hello").send(from: wallet, amount: Tez(1), completion: { result in
    switch result {
    case .failure(let error):
        XCTFail("Failed with error: \(error)")
        testCompletionExpectation.fulfill()
    case .success(_):
        testCompletionExpectation.fulfill()
    }
})

wallet and tezosClient should be created with TezosSwift Also note that right now the created code works with ReactiveSwift only.

Result of the call is either a String hash of the transaction or an TezosError.