Add process idea to README

README.md

@@ -9,3 +9,42 @@ Scripts to align a macOS system to Astzweig system configuration.
 
 ## What it does
 1. Run all setup from a temporary directory and delete it in the end
+
+## Process
+1. `install.sh` queries all modules for their required information
+1. The modules print their required information to stdout using the format as described below.
+1. `install.sh` parses those informations and tries to read them from a configuration file.
+1. If the configuration file does not have those informations, it asks the user.
+1. `install.sh` then runs the modules with their required informations passed in as parameter values.
+
+## Required Information Format
+Modules must print their required information to stdout if they're called with
+`--show-required-information` option. Required information are all information the
+module might want to ask the user in order to configure some aspect of the system.
+
+### Schema
+The general schema is:
+
+```zsh
+#(i|p|c|s) <PARAMETER NAME>=<QUESTION> [# (<arg name>: <arg value>) [(; <arg name>: <arg value>)...]]
+s: --highlight-color=What color shall your system highlight color be? # choose from: blue,red,light green;
+p: --user-password=What color shall your system highlight color be?
+```
+The letter at the beginning is the question type:
+
+| Question type | Description | Arguments |
+| ------------- | ----------- | --------- |
+| i (info) | A question where the user has no restrictions on input | - |
+| p (password) | A question where the user input is not printed to standard output. | - |
+| c (confirm) | A yes/no question where the user is allowed to answer yes or no. | - |
+| s (select) | A list of choices where the user can select one using numbers. | `choose from`: a comma separated list of possible select values. |
+
+`<PARAMETER NAME>` is the the parameter name, that will receive the user answer
+when the module is called. Single char parameter names will be prefixed with a
+single dash while multi char parameter names will be prefixed by double dashes.
+E.g. the parameter name `s` becomes `-s <user response>` on module call, while
+the parameter name `highlight-color` becomes `--highlight-color <user response>`.
+`<QUESTION>` must contain any punctuation you want to show.
+
+[^zshlib-askUser]: Currently supported: info, password, confirm, choose. They map to [zshlib/askUser][zshlib-overview] commands.
+[zshlib-overview]: https://github.com/astzweig/zshlib#whats-included