Solidity 2 UML

Unified Modeling Language (UML) class diagram generator for Solidity contracts.

Install

The following installation assumes Node.js has already been installed which comes with Node Package Manager (NPM).

To install globally so you can run sol2uml from anywhere

npm link sol2uml --only=production

Usage

To see the usage options

$ sol2uml -h
Usage: sol2uml <fileFolderAddress> [options]

Generates UML diagrams from Solidity source code.
If no file, folder or address is passes as the first argument, the working folder is used.
When a folder is used, all *.sol files are found in that folder and all sub folders.
If an Ethereum address with a 0x prefix is passed, the verified source code from Etherscan will be used.

Options:
  -v, --verbose                 With debugging statements
  -f, --outputFormat [value]    Output file format: svg, png, dot or all (default: "svg")
  -n, --outputFileName [value]  Output file name
  -c, --clusterFolders          Cluster contracts into source folders
  -h, --help                    output usage information

To generate a diagram of all contracts under the contracts folder and its sub folders

sol2uml ./contracts

To generate a diagram of EtherDelta's contracts from the verified source code on Etherscan. The output wil be a svg file 0x8d12A197cB00D4747a1fe03395095ce2A5CC6819.svg in the working folder.

sol2uml 0x8d12A197cB00D4747a1fe03395095ce2A5CC6819

To generate all Solidity files under some root folder and output the svg file to a specific location

sol2uml path/to/contracts/root/folder -n ./outputFile.svg

To generate a diagram of all contracts in a single Solidity file, the output file in png format to output file ./someFile.png

sol2uml path/to/contracts/root/folder/solidity/file.sol -f png -n ./someFile.png

To generate diagrams of all Solidity files under some root folder. The output will be contracts.svg and contracts.png files in the working folder.

sol2uml ./contracts -f all -v

Example from Open Zeppelin

Open Zeppelin's ERC20 token contracts Generated from version 2.3.0

See examples for more diagrams.

UML Syntax

Good online resources for learning UML

• UML 2 Class Diagramming Guidelines
• Creating class diagrams with UML

Terminology differences

A Solidity variable becomes an attribute in UML and a Solidity function becomes an operation in UML.

Stereotypes

Class stereotypes

• Interface
• Abstract - if any of the contract's functions are abstract, the class will have an Abstract stereotype. Child contracts of abstract contracts that do not implement all the abstract functions are currently not marked as Abstract.
• Library

Operator stereotypes

• event
• modifier
• abstract - is there is no function body on a contract, the operator is marked as abstract. Operators on an Interface do not have an abstract stereotype as all operators are abstract.
• fallback - abstract fallback functions will just have an abstract stereotype.
• payable - payable fallback functions will just have a fallback stereotype.

UML Associations

Lines:

• Solid lines are used to link the contract types of storage (state) variables. This can be linked to contracts, interfaces or libraries.
• Solid lines are also used for generalisations of contracts and abstract contracts.
• Solid lines are also used for aggregated structs and enums
• Dashed lines are used or generalisations of interfaces.
• Dash lines are also used for types of memory variables.

Heads/Tails:

• An empty triangle head is used for generalisations of contracts, interfaces and abstract contracts.
• An open arrow head is used for storage or memory variable dependencies
• A diamond tail is used for aggregations of structs and enums

About

This is a rewrite of the Richard Ramos's solidity-diagram-gen tool which no longer works as it uses solidity-parser which cannot handle newer Solidity syntax like constructor.

This version uses the solidity-parser-antlr Solidity parser which is built on top of ANTLR4 grammar. The logic to generate the dot syntax has been rewritten and different UML syntax is now used.

The diagrams are generated using viz.js which uses Graphviz to render a Scalable Vector Graphics (SVG) file. Graphviz Online allows dot files to be edited and rendered into a SVN dynamically.

TODO

• Document UML syntax
• Option to specify a list of contracts to generate along with their dependencies. This was not all contracts in dependent libraries like Open Zeppelin need to be generated.
• Portrait output mode
• Add indicator for state mutability. eg view and pure functions