rvest

• 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).

• Re-document to fix HTML issues in .Rd.

• Fixes for CRAN

• html_table() converts empty tables to empty tibbles (@epiben, #327).

• html_table() correctly handles tables with cells that contain blank values
  for rowspan and/or colspan, so that e.g. <td rowspan=""> is parsed as
  <td rowspan=1> (@epiben, #323).

• Fix broken example

(to be released as rvest 1.0.0)

New features

• New html_text2() provides a more natural rendering of HTML nodes into text,
  converting <br> into "\n", and removing non-significant whitespace (#175).
  By default, it also converts   into regular spaces, which you can
  suppress with preserve_nbsp = TRUE (#284).

• html_table() has been re-written from scratch to more closely mimic the
  algorithm that browsers use for parsing tables. This should mean that there
  are far fewer tables for which it fails to produce some output (#63, #204,
  #215). The fill argument has been deprecated since it is no longer needed.
  html_table() now returns a tibble rather than a data frame to be compatible
  with the rest of the tidyverse (#199). Its performance has been considerably
  improved (#237). It also gains a na.strings argument to control what values
  are converted to NA (#107), and a convert argument to control whether to
  run the conversion (#311).

• New html_form_submit() allows you to submit a form directly, without
  needing to create a session (#300).

• rvest is now licensed as MIT (#287).

API changes

Since this is the 1.0.0 release, I included a large number of API changes to make rvest more compatible with current tidyverse conventions. Older functions have been deprecated, so existing code will continue to work (albeit with a few new warnings).

• rvest now imports xml2 rather than depending on it. This is cleaner because
  it avoids attaching all the xml2 functions that you're less likely to use.
  To reduce the change of breakages, rvest re-exports xml2 functions
  read_html() and url_absolute(), but your code may now need an explicit
  library(xml2).

• html_form() now returns an object with class rvest_form (instead of form).
  Fields within a form now have class rvest_field, instead of a
  variety of classes that were lacking the rvest_ prefix. All functions for
  working with forms have a common html_form_ prefix: set_values() became
  html_form_set(). submit_form() was renamed to session_submit() because
  it returns a session.

• html_node() and html_nodes() have been superseded in favor of
  html_element() and html_elements() since they (almost) always return
  elements, not nodes (#298).

• html_session() is now session() and returns an object of class
  rvest_session (instead of session). All functions that work with session
  objects now have a common session_ prefix.

• Long deprecated html(), html_tag(), xml() functions have been removed.

• minimal_html() (which doesn't appear to be used by any other package)
  has had its arguments flipped to make it more intuitive.

• guess_encoding() has been renamed to html_encoding_guess() to avoid
  a clash with stringr::guess_encoding() (#209). repair_encoding() has
  been deprecated because it doesn't appear to work.

• pluck() is no longer exported to avoid a clash with purrr::pluck();
  if you need it use purrr::map_chr() and friends instead (#209).

• xml_tag(), xml_node(), and xml_nodes() have been formally deprecated
  in favor of their html_ equivalents.

Minor improvements and bug fixes

• The "harvesting the web" vignette has been rewritten to focus more on basics
  rvest, eliminating the screenshots to keep the installed package as svelte as
  possible. It's also been renamed to vignette("rvest") since it's the
  vignette that you should read first.

• The SelectorGadget vignette is now a web-only article,
  https://rvest.tidyverse.org/articles/articles/selectorgadget.html,
  so we can be more generous with screenshots since they're no longer bundled
  with every install of the package. Together with the rewrite of the other
  vignette, this means that rvest is now ~90 Kb instead of ~1.1 Mb.

• All uses of IMDB have been eliminated since the site explicitly prohibits
  scraping (#195).

• session_submit() errors if form doesn't have a url (#288).

• New session_forward() function to complement session_back().
  It now allows you to pick the submission button by position (#156).
  The ... argument is deprecated; please use config instead.

• html_form_set() can now accept character vectors allowing you to select
  multiple checkboxes in a set or select multiple values from a multi-<select>
  (#127, with help from @juba). It also uses dynamic dots so that you can use
  !!! if you have a list of values (#189).

• Remove failing example

• Use web archive to fix broken example.

• Remove unneeded read_xml.response() method (#242).

• Fix R CMD check failure

• submit_request() now checks for empty form-field-types to select the
  correct submit fields (@rentrop, #159)

• Fixes to follow_link() and back() to correctly manage session history.
• If you're using xml2 1.0.0, html_node() will now return a "missing node".
• Parse rowspans and colspans effectively by filling using repetition from
  left to right (for colspan) and top to bottom (rowspan) (#111)
• Updated a few examples and demos where the website structure has
  changed.
• Made compatible with both xml2 0.1.2 and 1.0.0.

• Fix invalid link for SSA example.
• Parse <options> that don't have value attribute (#85).
• Remove all remaining uses of html() in favor of read_html() (@jimhester,
  #113).

• rvest has been rewritten to take advantage of the new xml2 package. xml2
  provides a fresh binding to libxml2, avoiding many of the work-arounds
  previously needed for the XML package. Now rvest depends on the xml2
  package, so all the xml functions are available, and rvest adds a thin
  wrapper for html.
• A number of functions have change names. The old versions still work,
  but are deprecated and will be removed in rvest 0.4.0.
  • html_tag() -> html_name()
  • html() -> read_html()
• html_node() now throws an error if there are no matches, and a warning
  if there's more than one match. I think this should make it more likely to
  fail clearly when the structure of the page changes.
• xml_structure() has been moved to xml2. New html_structure() (also in
  xml2) highlights id and class attributes (#78).
• submit_form() now works with forms that use GET (#66).
• submit_request() (and hence submit_form()) is now case-insensitive,
  and so will find <input type=SUBMIT> as well as<input type="submit">.
• submit_request() (and hence submit_form()) recognizes forms with
  <input type="image"> as a valid form submission button per
  http://www.w3.org/TR/html-markup/input.image.html

New features

• html() and xml() pass ... on to httr::GET() so you can more
  finely control the request (#48).
• Add xml support: parse with xml(), then work with using xml_node(),
  xml_attr(), xml_attrs(), xml_text() and xml_tag() (#24).
• xml_structure(): new function that displays the structure (i.e. tag
  and attribute names) of a xml/html object (#10).

Bug fixes

• follow_link() now accepts css and xpath selectors. (#38, #41, #42)
• html() does a better job of dealing with encodings (passing the
  problem on to XML::parseHTML()) instead of trying to do it itself
  (#25, #50).
• html_attr() returns default value when input is NULL (#49)
• Add missing html_node() method for session.
• html_nodes() now returns an empty list if no elements are found (#31).
• submit_form() converts relative paths to absolute URLs (#52).
  It also deals better with 0-length inputs (#29).

Initial release