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Standalone Use

Source: vignettes/standalone.Rmd
standalone.Rmd

Some packages want schemate functionality without taking a runtime dependency on schemate. For that use case, the project publishes a generated standalone bundle on the standalone branch.

Import

Run this from the target package:

usethis::use_standalone("hongyuanjia/schemate", "schema", ref = "standalone")

The imported file contains the same core schema_ API used by the package: schema_infer(), the edit helpers, schema_write(), schema_read(), and schema_validate().

The target package must still declare the standalone imports. Core schema inference, editing, printing, and validation need checkmate and S7. schema_read() and schema_write() use jsonlite at runtime, so packages that call those functions should list jsonlite in Suggests or Imports.

Imports:
    checkmate (>= 2.0.0),
    S7
Suggests:
    jsonlite

When jsonlite is not installed, JSON IO fails with an installation hint. Printing still works through a small base R fallback.

Register S7 classes and methods

Next, create a .onLoad() in zzz.R that calls S7::methods_register():

.onLoad <- function(libname, pkgname) {
    S7::methods_register()
}

This is S7’s way of registering methods.