htmlunit/README.Rmd

---
output: rmarkdown::github_document
---
```{r include=FALSE}
knitr::opts_chunk$set(message=FALSE, warning=FALSE)
```
# htmlunit

Tools to Scrape Dynamic Web Content via the 'HtmlUnit' Java Library

## Description

`HtmlUnit` (<http://htmlunit.sourceforge.net/>) is _a "'GUI'-Less 
browser for 'Java' programs". It models 'HTML' documents and provides an 'API' 
that allows one to invoke pages, fill out forms, click links and more just like 
one does in a "normal" browser. The library has fairly good and constantly
improving 'JavaScript' support and is able to work even with quite complex 'AJAX' 
libraries, simulating 'Chrome', 'Firefox' or 'Internet Explorer' depending on
the configuration used. It is typically used for testing purposes or to retrieve 
information from web sites._

Tools are provided to work with this library at a higher level than provided by
the exposed 'Java' libraries in the [`htmlunitjars`](https://gitlab.com/hrbrmstr/htmlunitjars)
package.

## What's Inside The Tin

The following functions are implemented:

- `hu_read_html`:	Read HTML from a URL with Browser Emua;tion & in a JavaScript Context

## Installation

```{r eval=FALSE}
devtools::install_github("hrbrmstr/htmlunitjars")
devtools::install_github("hrbrmstr/htmlunit")
```

```{r message=FALSE, warning=FALSE, error=FALSE, include=FALSE}
options(width=120)
```

## Usage

```{r message=FALSE, warning=FALSE, error=FALSE}
library(htmlunit)

# current verison
packageVersion("htmlunit")

```

Something `xml2::read_html()` cannot do, read the table from <https://hrbrmstr.github.io/htmlunitjars/index.html>:

![](man/figures/test-url-table.png)

```{r}
test_url <- "https://hrbrmstr.github.io/htmlunitjars/index.html"

pg <- xml2::read_html(test_url)

html_table(pg)
```

☹️

But, `hu_read_html()` can!

```{r}
pg <- hu_read_html(test_url)

html_table(pg)
```

All without needing a separate Selenium or Splash server instance.