Work with valid configurations

S7schema() provides a generic way of working with yaml configuration files.

The object is created by supplying both an initial YAML configuration (file) and the JSON schema definition (schema) of the configuration file.

The initial configuration is validated before the new object is returned. If not valid the first error is thrown, together with a path to the entry in the YAML file, and a description of the error.

The S7schema class inherits from list, ensuring that the content of the YAML file can be accessed as if read directly with yaml::read_yaml(), and supports the below workflow:

1. Read and validate config file: x <- S7schema(...)

2. Edit content as if it was a list: x$new_entry <- "new_value"

3. Validate new content against the original schema: validate(x)

4. Use values in downstream functions: x$new_entry

Usage

S7schema(file, schema, .data)

Arguments

file

character(1) path to a yaml file to be checked. Or NULL if created using .data.

schema

character(1) path to a JSON schema.

.data

list() input to create the object. Mutually exclusive with file.

Value

New S7schema object.

Details

See internal validator() documentation for more info on how the validation is done.

Properties

schema

character(1) path to JSON schema being used to validate against.

validator

Internal validator() used to validate the content (read-only).

file

character(1) path to the source YAML file (or NULL if not set).

Examples

# Work with yaml configuration file:
S7schema(
  file = system.file("examples/config.yml", package = "S7schema"),
  schema = system.file("examples/schema.json", package = "S7schema")
)
#> <S7schema::S7schema> List of 1
#>  $ my_config_var: int 1
#>  @ schema   : chr "/home/runner/work/_temp/Library/S7schema/examples/schema.json"
#>  @ validator: <S7schema::validator>
#>  .. @ context:Classes 'V8', 'environment' <environment: 0x561cc4e09678> 
#>  @ file     : chr "/home/runner/work/_temp/Library/S7schema/examples/config.yml"

# Create object in memory
S7schema(
  .data = list(my_config_var = 6),
  schema = system.file("examples/schema.json", package = "S7schema")
)
#> <S7schema::S7schema> List of 1
#>  $ my_config_var: num 6
#>  @ schema   : chr "/home/runner/work/_temp/Library/S7schema/examples/schema.json"
#>  @ validator: <S7schema::validator>
#>  .. @ context:Classes 'V8', 'environment' <environment: 0x561cc51e04c0> 
#>  @ file     : NULL