configen

A command line tool to auto-generate configuration file code, for use in Xcode projects.

The configen tool is used to auto-generate configuration code from a property list. It is intended to create the kind of configuration needed for external URLs or API keys used by your app.

Usage

Before running the configen tool, you need to create a mapping file, in which you define the configuration variables you support. For example:

entryPointURL : NSURL
searchURL : NSURL
retryCount : Int
adUnitPrefix : String
pushKey : String
analyticsKey : String
environment : Environment

Then you need to create a property list file, in which you provide values for each of the keys defined in your mapping file, above.

Finally, invoke the configen tool as follows:

configen <plist> <mapping-file> <output-class-name> <output-directory>

# e.g.

configen EnvironmentConfig/EnvironmentConfig.plist EnvironmentConfig.map EnvironmentConfig EnvironmentConfig

Standard types supported

• Int: Expects integer type in plist
• String: Expects string type in plist
• Bool: Expects Boolean type in plist
• Double: Expects floating point type in plist
• NSURL: Expects a string in the plist, which can be converted to an NSURL (validated at compile time)

Custom types

Any other type is supported, by providing a string in the plist which compiles successfully when converted to code. For example:

enum Environment {
  case Development
  case UAT
  case Production
}

Providing the mapping type environment : Environment in the mapping file, and the string .Production in the plist, the property in your configuration class will be as follows:

  static let environment: Environment = .Production

This is powerful, because it allows you to work with optionals, which are not supported by the standard types. For example:

Mapping file:

retryCount : Int?

You have to make the type in your plist a string, and input either a number -- e.g. 1 -- or the word nil, so the output property becomes, for example:

  static let retryCount: Int? = nil

Supporting multiple environments

The best way to support multiple environments is to define a separate scheme for each one. Then create an external build step for each scheme. In the external build step, you run configen with different parameters depending on the environment being built.

To-do list

• Change the way arguments are passed to the script on the command line. We should pass named parameters.
• Support Objective-C code generation.