---
title: "Getting Started with cdiscdata"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{Getting Started with cdiscdata}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r setup, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
library(cdiscdata)
```

## Overview

`cdiscdata` provides versioned CDISC reference data as a standard R package:

- **Controlled Terminology (CT)**: SDTM and ADaM CT from the NCI EVS FTP site,
  all historical versions in a single compact table.
- **Define-XML schemas (XSD)**: For validating define.xml files.
- **XSLT stylesheets**: For rendering define.xml as HTML.

## Discovering what is available

```{r}
list_datasets()
cdiscdata_versions()
```

## Controlled Terminology

Retrieve the latest CT:

```{r}
ct <- get_ct("sdtm")
nrow(ct)
head(ct[, c("codelist_code", "codelist_name", "term", "decoded_value")])
```

Retrieve a specific historical version:

```{r}
versions <- available_ct_versions("sdtm")
head(versions)

# Get CT as it was at the second-most-recent release
if (length(versions) >= 2) {
  ct_old <- get_ct("sdtm", version = versions[[2]])
  nrow(ct_old)
}
```

## Define-XML schemas and stylesheets

```{r}
schema_path("2.1")
stylesheet_path("2.1")
```

Use `get_dataset()` as a unified entry point:

```{r}
get_dataset("define_xml_schema", version = "2.1")

ct_via_generic <- get_dataset("ct_sdtm")
nrow(ct_via_generic)
head(ct_via_generic[, c("codelist_code", "term", "valid_from", "valid_to")])
```