03-scaffold.md

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Scaffold

We'll be using a tool called scaffold to help us spin up a boilerplate app quickly. To use scaffold first clone and install it on your local machine:

git clone [email protected]:cosmos/scaffold.git
cd scaffold
make tools
make install
scaffold --help

Afterwards, you should see the following help screen displayed:

This CLI helps in scaffolding out CosmosSDK based applications

Usage:
  scaffold [command]

Available Commands:
  app         Generates an empty application boilerplate
  help        Help about any command
  module      Generate an empty module for use in the Cosmos-SDK
  tutorial    Generates one of the tutorial apps, currently either the 'nameservice' or 'hellochain'

Flags:
  -c, --config string        config file (default is $HOME/.scaffold.yaml)
  -h, --help                 help for scaffold
  -o, --output-path string   Path to output
  -t, --toggle               Help message for toggle

Use "scaffold [command] --help" for more information about a command.

Now that you have the scaffold command available try looking at the help screen of the app command by typing scaffold app --help.

Generates an empty application boilerplate

Usage:
  scaffold app [lvl] [user] [repo] [flags]

Flags:
  -h, --help   help for app

Global Flags:
  -c, --config string        config file (default is $HOME/.scaffold.yaml)
  -o, --output-path string   Path to output

We will use this command to generate a basic boilerplate application. First create a new working directory on your machine that you can use to start a new project. You might want to do this in your home directory by using cd ~. It doesn't really matter where but you probably don't want to stay inside of your scaffold directory.

When it comes to starting your project with the scaffold app command, the parameter lvl should be filled with lvl-1 (which is currently the only lvl available). You should use your own github username for user and come up with a name for repo. I will be using scavenge as the repo name for this tutorial. Using my own github handle (okwme) the final command should look like:

scaffold app lvl-1 okwme scavenge

This should generate a folder structure inside of a directory called scavenge of your current working directory. Now that we have an app boilerplate we want to add some custom functionality to it and build our scavenge module. Change into the modules directory with cd scavenge/x. Now you can run the module command of the scaffold tool, but first check out the help screen of it with scaffold module --help:

Generate an empty module for use in the Cosmos-SDK

Usage:
  scaffold module [user] [repo] [moduleName] [flags]

Flags:
  -h, --help   help for module

Global Flags:
  -c, --config string        config file (default is $HOME/.scaffold.yaml)
  -o, --output-path string   Path to output

Similarly, it asks for your github username as user and the name repository name as repo. It also asks for the name you'd like to give to this new module. I will use the name scavenge for the module as well.

scaffold module okwme scavenge scavenge

Now that we have generated a boilerplate application with a boilerplate module, our next step will be to define our Messages.