Provide chromote based scraping (#362)

New `read_html_live()` reads HTML into a real, live, HTML browser, meaning that you can scrape HTML generated by javascript. It returns a `LiveHTML` object which you can also use to simulate user interactions with the page, like clicking, typing, and scrolling 

Fixes #245.

.Rbuildignore

@@ -14,3 +14,4 @@
 ^LICENSE\.md$
 ^vignettes/articles$
 ^CRAN-SUBMISSION$
+^data-raw$

DESCRIPTION

@@ -23,6 +23,7 @@ Imports:
     tibble,
     xml2 (>= 1.3)
 Suggests:
+    chromote,
     covr,
     knitr,
     R6,
@@ -41,4 +42,4 @@ Config/testthat/parallel: true
 Encoding: UTF-8
 Language: en-US
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.3.0
+RoxygenNote: 7.3.1

NAMESPACE

@@ -3,14 +3,17 @@
 S3method(cookies,rvest_session)
 S3method(format,rvest_field)
 S3method(headers,rvest_session)
+S3method(html_element,LiveHTML)
 S3method(html_element,default)
 S3method(html_element,rvest_session)
+S3method(html_elements,LiveHTML)
 S3method(html_elements,default)
 S3method(html_elements,rvest_session)
 S3method(html_form,rvest_session)
 S3method(html_form,xml_document)
 S3method(html_form,xml_node)
 S3method(html_form,xml_nodeset)
+S3method(html_table,LiveHTML)
 S3method(html_table,rvest_session)
 S3method(html_table,xml_document)
 S3method(html_table,xml_node)
@@ -25,6 +28,7 @@ S3method(print,rvest_session)
 S3method(read_html,rvest_session)
 S3method(status_code,rvest_session)
 export("%>%")
+export(LiveHTML)
 export(back)
 export(follow_link)
 export(forward)
@@ -50,6 +54,7 @@ export(is.session)
 export(jump_to)
 export(minimal_html)
 export(read_html)
+export(read_html_live)
 export(repair_encoding)
 export(session)
 export(session_back)

NEWS.md

@@ -1,5 +1,10 @@
 # rvest (development version)
 
+* New `read_html_live()` reads HTML into a real, live, HTML browser, meaning 
+  that you can scrape HTML generated by javascript. It returns a `LiveHTML`
+  object which you can also use to simulate user interactions with the page,
+  like clicking, typing, and scrolling (#245).
+
 * `html_table()` discards rows without cells (@epiben, #360).
 
 # rvest 1.0.3