Configuration Files
General Information
ENiGMA½ configuration files such as the system config, menus and themes are formatted in the HJSON format.
Hot-Reload
Nearly all of ENiGMA½’s configuration can be hot-reloaded. That is, a live system can have it’s configuration modified and it will be loaded in place.
Monitoring live logs is useful when making live changes. The system will complain if something is wrong!
Common Directives
Includes
Most configuration files offer an includes
directive that allows users to break up large configuration files into smaller and organized parts. For example, consider a system with many menus/screens. Instead of a single menu.hjson
, the SysOp may break this into message-base.hjson
, file-base.hjson
, etc.
The includes
directive may be used the top-level scope of a configuration file:
// menu.hjson
{
includes: [
message-base.hjson
file-base.hjson
]
menus: {
someOtherMenu: {
// ...
}
}
}
// message-base.hjson
{
menus: {
someMessageMenu: {
// ...
}
}
}
References
Often times in a configuration you will find that you’re repeating yourself quite a bit. ENiGMA½ provides an @reference
that can help with this in the form of @reference:dot.path.to.section
.
Consider actionKeys
in a menu. Often times you may show a screen and the user presses Q
or ESC
to fall back to the previous. Instead of repeating this in many menus, a generic block can be referenced:
{
// note that 'recycle' here is arbitrary;
// only 'menus' and 'prompts' is reserved at this level.
recycle: {
prevMenu: [
{
keys: [ "escape" ]
action: @systemMethod:prevMenu
}
]
}
menus: {
someMenu: {
form: {
0: {
actionKeys: @reference:recycle.prevMenu
}
}
}
}
}
An unresolved @reference
will be left intact.
Environment Variables
Especially in a container environment such as Docker, environment variable access in configuration files can become very handy. ENiGMA½ provides a flexible way to access variables using the @environment
directive. The most basic form of @environment:VAR_NAME
produces a string value. Additionally a :type
suffix can be supplied to coerece the value to a particular type. Variables pointing to a comma separated list can be turned to arrays using an additional :array
suffix.
Below is a table of the various forms:
Form | Variable Value | Produces |
---|---|---|
@environment:SOME_VAR |
“Foo” |
"Foo" (without quotes) |
@environment:SOME_VAR |
“123” |
"123" (without quotes) |
@environment:SOME_VAR:string |
“Bar” |
"Bar" (without quotes) |
@environment:SOME_VAR:string:array |
“Foo,Bar” | [ 'Foo', 'Bar' ] |
@environment:SOME_VAR:boolean |
“1” | true |
@environment:SOME_VAR:boolean |
“True” | true |
@environment:SOME_VAR:boolean |
“false” | false |
@environment:SOME_VAR:boolean |
“cat” | false |
@environment:SOME_VAR:boolean:array |
“True,false,TRUE” | [ true, false, true ] |
@environment:SOME_VAR:number |
“123” | 123 |
@environment:SOME_VAR:number:array |
“123,456” | [ 123, 456 ] |
@environment:SOME_VAR:number |
“kitten” | (invalid) |
@environment:SOME_VAR:object |
’{“a”:”b”}’ | { 'a' : 'b' } |
@environment:SOME_VAR:object:array |
’{“a”:”b”},{“c”:”d”}’ | [ { 'a' : 'b' }, { 'c' : 'd' } ] |
@environment:SOME_VAR:timestamp |
“2020-01-05” | A moment object representing 2020-01-05 |
@environment:SOME_VAR:timestamp:array |
“2020-01-05,2016-05-16T01:15:37’” | An array of moment objects representing 2020-01-05 and 2016-05-16T01:15:37 |
bool
may be used as an alias to boolean
.
timestamp
values can be in any form that moment can parse.
An unresolved or invalid @environment
will be left intact.
Consider the following fragment:
{
foo: {
bar: @environment:BAR_VAR:number
}
}
If the environment has BAR_VAR=1337
, this would produce:
{
foo: {
bar: 1337
}
}