How to use [config.get]

The reference page of config.get has its arguments, constraints and declaration.

This slot allows you to retrieve configuration settings. To retrieve settings you can supply a “path” such as “foo:bar” to for instance an invocation to [config.get]. This will traverse into your “foo” config setting, find its “bar” key, and return the value of your “bar” key. Below is an example of usage.

config.get:"foo:bar"

Assuming your configuration file looks like the following.

{
   "foo": {
      "bar": 42
   }
}

… afterwards the value of your [config.get] node will be the following.

config.get:42

Notice - Due to implementation details of .Net and its IConfiguration specifically, values returned will always be strings, and you’ll have to manually convert these to other types, using for instance the [convert] slot from magic.lambda. This might change in a future release though. You can also provide a default value that will be returned if no configuration value is found, such as the following illustrates.

.foo:foo
config.get:"magic:foo:non-existing-key"
   get-value:x:@.foo

Since the above “non-existing-key” doesn’t exist in your configuration file, the above Hyperlambda will return the value “foo” being the result of the invocation to the [get-value] slot. This allows you to create default values your code resorts to if the specified configuration setting doesn’t exist.