• implement Crossref's REST API updates for the public and polite pool
• change of maintainer

MINOR IMPROVEMENTS

• move bibtex package to Suggests as it has been orphaned, use it conditionally (#209)
• change all uses of tibble::tbl_df to tibble::as_tibble (#206)
• additional fields now parsed in the cr_works() output: short-container-title, references-count, is-referenced-by-count, language, content-domain, and update-to (#208)

MINOR IMPROVEMENTS

• docs page vignette has names (#197)
• query.title field query is no longer supported by Crossref, removed from package (#198)
• fix some links in readme (#199)
• improve documentation for how to do deep paging (new section "Deep paging"), and how to use the cursor specifically (#190)

BUG FIXES

• fix error when progress used and when limit param not used (#190)
• encoding fix for the Crossref RStudio Addin (#194) (#201)

NEW FEATURES

• cr_funders(), cr_journals(), cr_licenses(), cr_members(), cr_prefixes(), cr_types(), cr_works() gain ability to show a progress bar when using deep pagination when using works=TRUE (#186) (#188)

MINOR IMPROVEMENTS

• fix a test fixture that had non-ascii characters (#187)
• cr_works() returned a tibble in the $data slot in each case except for when a single DOI was passed to the doi parameter. now fixed (#184) thanks @martinjhnhadley

NEW FEATURES

• big Crossref Addin update (#171) all work by @haozhu233
• Async HTTP introduced for cr_works(), cr_works_(), and cr_citation_count(). See the new parameter async (logical) in those functions. For cr_citation_count(), it now accepts more than 1 DOI, and the output has changed from a numeric value to a data.frame (columns: doi and count). With async=TRUE for cr_works() you get a list of data.frame's; while for cr_works_() you get a list of JSON's (#121) (#160) (#182)

MINOR IMPROVEMENTS

• package tests now using vcr for HTTP request/response caching (#178) (#179)
• in works data, now returning published-print and published-online fields (#181)
• add new filters for /works routes (when works = TRUE): isbn, reference_visibility, has_content_domain, and has_domain_restriction (#176) (#177)
• add new return element in /works routes (when works = TRUE): $reference gives the references cited in the article (these are not the articles citing the target article, sorry) (#176)
• improve documentation on the "polite pool". If you supply an email address Crossref will put you in the polite pool (#173) (#175) thanks @poldham
• added example to cr_abstract() of handling many DOIs while allowing for failures without stopping progress (#174) thanks @zackbatist

BUG FIXES

• fix internal parsing of funder data in cr_works() (#180) thanks @nicholasmfraser for the bug report
• fix for cr_citation_count(): when given a bad/invalid/malformed DOI, throw warning and give back an NA (#164) thanks for the report @chreman
• Fix for instances in the package where we incorrectly were doing logical comparison's; detected via R_CHECK_LENGTH_1_LOGIC2

NEW FEATURES

• The RStudio Addin now includes ability to search by article metadata, e.g., title (#148) (#152)
• you can now set a different base url for cr_cn() (#168)

MINOR IMPROVEMENTS

• better behavior for cr_cn() when bibentry not valid, that is not parseable. before the package we use to parse bibtex would stop on invalid bibentry data, but now we get around the invalid bits and give back the bibentry (#147)
• updated and improved documentation for filters (#161)
• improved description of the dois parameter (#162) thanks @ms609
• Much improved error behavior for cr_* functions. We now give errors like 404 (client error): /works/blblbl - Resource not found., which includes HTTP status code, major class of error (success, redirect, client, server), the route requested, and the error message (#163)

BUG FIXES

• fixed bug in cr_works() in which field queries should have been possible for title and affilitation, but were not. Fixed now. (#149)
• cr_journals() was not correctly parsing data when more than 1 ISSN given and works set to TRUE, fixed now (#156)
• cr_journals() was not correctly parsing data when no ISSN found and works set to TRUE, fixed now (#150)
• cr_journals() was not correctly handling queries with multiple ISSN's and works set to FALSE, fixed now (#151)
• fixed bug in cr_works(), and any other cr_* function that set works=TRUE. the license slot can have more than 1 result, and we were only giving the first back. fixed the parsing on this to give back all license results (#170)

NEW FEATURES

• Include documentation and internals to support passing a user
  supplied email to Crossref to get put into higher rate limit
  pool (#145) thanks @njahn82
• Functions that operate on the /works route gain a select
  parameter to select certain fields to return (#146)

MINOR IMPROVEMENTS

• Updated docs for additional options for the sort parameter (#142)
• Updated docs for additional options for doing field queries (the
  flq parameter) (#143)
• Filters: New filters added to the package, and some removed
  (e.g, publisher-name). You can see the filters with the
  functions filter_details/filter_names. Beware, some filters
  error sometimes with the Crossref API - they may not work, but they may, let me know at https://github.com/ropensci/rcrossref/issues or let Crossref know at https://github.com/CrossRef/rest-api-doc/issues (#136) (#139) (#141)

NEW FEATURES

• All text mining functionality moved into a new package: crminer
  https://github.com/ropensci/crminer . Functions that did
  text mining stuff now defunct, see ?rcrossref-defunct (#122)
• All Crossref API requests now using https instead of http (#133)

MINOR IMPROVEMENTS

• replace xml2::xml_find_one with xml2::xml_find_first (#128)
  thanks @njahn82
• replaced httr with crul for HTTP requests (#132)
• Now using markdown for documentation (#135)
• Added more documentation to cr_journals and cr_works
  about what the returned data fields backfile_dois and current_dois
  really mean (#105) thanks @SteveViss

BUG FIXES

• Fix to cr_prefixes to not fail when no results found (#130)
  thanks @globbestael
• Fixed cr_works to allow queries like facet = license:* to be
  passed to facet parameter (was always allowed by Crossref, but we
  neglected to allow it - previously only allowed a boolean) (#129)
• Fixed cr_funders and cr_journals to give back facet data along
  with other data (#134)
• Fix to cr_* functions to check for a missing content-type
  headers and instead of failing, we continue anyway and try to parse
  data as sometimes Crossref doesn't give back a content type header
  at all (#127)

NEW FEATURES

• Added support for field queries (see
  https://github.com/CrossRef/rest-api-doc/blob/master/rest_api.md#field-queries
  for information on them). Means that you can query on specific fields rather
  than using query parameter which queries across all fields (#111)
• Now using rappdirs for local storage and caching for cr_ft_text (#106)

MINOR IMPROVEMENTS

• Added to man files where appropriate new 10K max value for the
  offset parameter (#126)
• Added to pkg level man file new rate limit headers included,
  and how users can get to those, via config=verbose() call (#124)
• Better failure modes on input parameters, still more work to do
  surely (#101)
• sleeping now between tests to avoid making crossref rate
  limit gate keepers mad (#125)
• cr_search and cr_search_free are now defunct. They were marked
  deprecated in previous version, and warned of defunctifying, and now
  they are defunct. Similar functionality can be done with e.g., cr_works()
  (#102)
• crosscite is now defunct. The functionality of this function can be
  achieved with cr_cn() (#82)
• cr_fundref is now defunct. Crossref changed their name fundref
  to funders, so we've changed our function, see cr_funders() (#83)
• parameter sample maximum value is now 100, was previously 1000.
  documentation updated. (#118)
• New filters has-clinical-trial-number and has-abstract added to
  the package, see ?filters for help (#120)

NEW FEATURES

• Addded an RStudio Addin for searching for citations. See ?rcrossref for
  more. Addin authored by Hao Zhu @haozhu233 (#114)
• New function cr_abstract() that tries to get an abstract via XML provided by
  Crossref - NOTE: an abstract is rarely available though (#116)

BUG FIXES

• Fixed bug in cr_cn() where DOIs with no minting agency found were
  failing because we were previously stopping when no agency found.
  Now, we just assume Crossref and move on from there. (#117)
  thanks @dfalster !
• Fix to cr_r() when number requested > 100. Actual fix is in
  cr_works(). Max for sample used to be 1000, asked this on the
  Crossref API forum,
  see CrossRef/rest-api-doc#146 (#115)
• Fix to cr_journals() in internal parsing, was failing in cases
  where ISSN array was of length zero