# plumber 1.2.0

## Breaking changes

* First line of endpoint comments interpreted as OpenAPI 'summary' field and subsequent comment lines interpreted as 'description' field. (@wkmor1 #805)

## New features

* Static file handler now serves HEAD requests. (#798)

* Introduces new GeoJSON serializer and parser. GeoJSON objects are parsed into `sf` objects and `sf` or `sfc` objects will be serialized into GeoJSON. (@josiahparry, #830)

* Add new Octet-Stream serializer. This is a wrapper around the Content Type serializer with type `application/octet-stream`. (#864)

* Update feather serializer to use the arrow package. The new default feather MIME type is `application/vnd.apache.arrow.file`. (@pachadotdev #849)

* Add parquet serializer and parser by using the arrow package (@pachadotdev #849)

* Updated example `14-future` to use `promises::future_promise()` and added an endpoint that uses `{coro}` to write _simpler_ async / `{promises}` code (#785)

* Add `path` argument to `pr_cookie()` allowing Secure cookies to define where they are served (@jtlandis #850)

## Bug fixes

* OpenAPI specification collision when using `examples`. (@meztez #820)

* Static handler returns Last-Modified response header. (#798)

* OpenAPI response type detection had a scoping issue. Use serializer defined `Content-Type` header instead. (@meztez, #789)

* The default shared secret filter returns error responses without throwing an error. (#808)

* Remove response bodies (and therefore the Content-Length header) for status codes which forbid it under the HTTP specification (e.g. 1xx, 204, 304). (@atheriel #758, @meztez #760)

* Decode path URI before attempting to serve static assets (@meztez #754).


# plumber 1.1.0

## Breaking changes

* Force json serialization of endpoint error responses instead of using endpoint serializer. (@meztez, #689)

* When plumbing a Plumber file and using a Plumber router modifier (`#* @plumber`), an error will be thrown if the original router is not returned. (#738)

* `options_plumber()` now requires that all options are named. If no option name is provided, an error with be thrown. (#746)

## New features

* Added option `plumber.trailingSlash`. This option (which is **disabled** by default) allows routes to be redirected to route definitions with a trailing slash. For example, if a `GET` request is submitted to `/test?a=1` with no `/test` route is defined, but a `GET` `/test/` route definition does exist, then the original request will respond with a `307` to reattempt against `GET` `/test/?a=1`. This option will be _enabled_ by default in a future release. This logic executed for before calling the `404` handler. (#746)

* Added an experimental option `plumber.methodNotAllowed`. This option (which is enabled by default) allows for a status of `405` to be returned if an invalid method is used when requesting a valid route. This logic executed for before calling the default `404` handler. (#746)

* Passing `edit = TRUE` to `plumb_api()` will open the API source file. (#699)

* OpenAPI Specification can be set using a file path. (@meztez #696)

* Guess OpenAPI response content type from serializer. (@meztez #684)

* Undeprecated `Plumber$run(debug=, swaggerCallback=)` and added the parameters for `Plumber$run(docs=, quiet=)` and `pr_run(debug=, docs=, swaggerCallback=, quiet=)`. Now, all four parameters will not produce lingering effects on the `Plumber` router. (@jcheng5 #765)
  * Setting `quiet = TRUE` will suppress routine startup messages.
  * Setting `debug = TRUE`, will display information when an error occurs. See `pr_set_debug()`.
  * Setting `docs` will update the visual documentation. See `pr_set_docs()`.
  * Set `swaggerCallback` to a function which will be called with a url to the documentation, or `NULL` to do nothing. See `pr_set_docs_callback()`.

* To update a `PlumberEndpoint` path after initialization, call the new `PlumberEndpoint$setPath(path)`. This will update internal path matching meta data. (Active bindings were not used to avoid breaking changes.) (@blairj09 #770)

* `PlumberStep` (and `PlumberEndpoint` and `PlumberFilter`) received a new field `$srcref` and method `$getFunc()`. `$srcref` will contain the corresponding `srcref` information from original source file. `$getFunc()` will return the evaluated function. (#782)

* Allow for spaces in `@apiTag` and `@tag` when tag is surrounded by single or double quotes. (#685)

## Bug fixes

* Ignore regular comments in block parsing. (@meztez #718)

* Block parsing comments, tags and responses ordering match plumber api ordering. (#722)

* Fixed bug where `httpuv` would return a status of `500` with body `An exception occurred` if no headers were set on the response object. (#745)

* Fixed bug where all `pr_*()` returned invisibly. Now all `pr_*()` methods will print the router if displayed in the console. (#740)

* When calling `Plumber$handle()` and defining a new `PlumberEndpoint`, `...` will be checked for invalid names. (@meztez, #677)

* `/__swagger__/` now always redirects to `/__docs__/`, even when Swagger isn't the selected interface. Use `options(plumber.legacyRedirects = FALSE)` to disable this behavior. (@blairj09 #694)

* Fixed `available_apis()` bug where all packages printed all available APIs. (@meztez #708)

* Fixed Plumber `$routes` resolution bugs. Routes are now returned in lexicographical order. (@meztez #702)

* Plumber will now display a circular reference if one is found while printing. (#738)

* Changed `future::plan()` from `multiprocess` to `multisession` in example API `14-future` as "Strategy 'multiprocess' is deprecated in future (>= 1.20.0)". (#747)

* Setting options `plumber.docs.callback` to `NULL` will also set deprecated but supported option `plumber.swagger.url`. (#766)

# plumber 1.0.0

## New features

### Plumber router

* Added support for promises in endpoints, filters, and hooks.  This allows for multi-core execution when paired with `future`. See `plumb_api("plumber", "13-promises")` and `plumb_api("plumber", "14-future")` for example implementations. (#248)
* Added a Tidy API for more natural usage with magrittr's `%>%`. For example, a plumber object can now be initiated and run with `pr() %>% pr_run(port = 8080)`. For more examples, see [here](https://www.rplumber.io/articles/programmatic-usage.html) (@blairj09, #590)

* Added support for `#' @plumber` tag to gain programmatic access to the `plumber` router via `function(pr) {....}`. See `system.file("plumber/06-sessions/plumber.R", package = "plumber")` and how it adds cookie support from within `plumber.R`. (@meztez and @blairj09, #568)

* Added `plumb_api()` for standardizing where to locate (`inst/plumber`) and how to run (`plumb_api(package, name)`) plumber apis inside an R package. To view the available Plumber APIs, call `available_apis()`. (#631)

* Improved argument handling in Plumber Endpoint route definitions. See `system.file("plumber/17-arguments/plumber.R", package = "plumber")` to view an example with expected output and `plumb_api("plumber", "17-arguments")` to retrieve the api. Improvements include:
  * The value supplied to `req` and `res` arguments in a route definition are now _always_ Plumber request and response objects. In the past, this was not guaranteed. (#666, #637)
  * To assist with conflicts in argument names deriving from different locations, `req$argsQuery`, `req$argsPath`, and `req$argsBody` have been added to access query, path, and `req$body` parameters, respectively. For this reason, we suggest defining routes with only `req` and `res` (i.e., `function(req, res) {}`) and accessing argument(s) under these new fields to avoid naming conflicts. (#637)
  * An error is no longer thrown if multiple arguments are matched to an Plumber Endpoint route definition. Instead, Plumber now retains the first named argument according to the highest priority match (`req$argsQuery` is 1st priority, then `req$argsPath`, then `req$argsBody`). (#666)
  * Unnamed elements that are added to `req$args` by filters or creating `req$argsBody` will no longer throw an error. They will only be passed through via `...` (#666)


### OpenAPI

* API Documentation is now hosted at `/__docs__`. If `swagger` documentation is being used, `/__swagger__` will redirect to `/__docs__`. (#654)

* Added OpenAPI support for array parameters using syntax `name:[type]` and new type `list` (synonym df, data.frame). (@meztez, #532)

* Added user provided OpenAPI Specification handler to Plumber router. Use `$setApiSpec()` to provide a function to alter the Plumber generated OpenAPI Specification returned by Plumber router method `$getApiSpec()`. This also affects `/openapi.json` and `/openapi.yaml` (#365)(@meztez, #562)

* Added `validate_api_spec()` to validate a Plumber API produces a valid OpenAPI Specification. (Experimental!) (#633)

### Serializers

* Added `as_attachment(value, filename)` method which allows routes to return a file attachment with a custom name. (#585)

* Serializer functions can now return `PlumberEndpoint` `preexec` and `postexec` hooks in addition to a `serializer` function by using `endpoint_serializer()`.  This allows for image serializers to turn on their corresponding graphics device before the route executes and turn the graphics device off after the route executes. (#630)

* PNG, JPEG, and SVG image serializers have been exported in methods `serializer_png()`, `serializer_jpeg()`, and `serializer_svg()` respectively.  In addition to these methods, `serializer_tiff()`, `serializer_bmp()`, and `serializer_pdf()` have been added. Each graphics device serializer wraps around `serializer_device()`, which should be used when making more graphics device serializers. (#630)

* New serializers
  * `serializer_yaml()`: Return an object serialized by `yaml` (@meztez, #556)
  * `serializer_csv()`: Return a comma separated value (@pachamaltese, #520)
  * `serializer_tsv()`: Return a tab separated value (#630)
  * `serializer_feather()`: Return a object serialized by `feather` (#626)
  * `serializer_text()`: Return text content (#585)
  * `serializer_cat()`: Return text content after calling `cat()` (#585)
  * `serializer_print()`: Return text content after calling `print()` (#585)
  * `serializer_format()`: Return text content after calling `format()` (#585)
  * `serializer_svg()`: Return an image saved as an SVG (@pachamaltese, #398)
  * `serializer_headers(header_list)`: Method which sets a list of static headers for each serialized value. Heavily inspired from @ycphs (#455). (#585)
  * `serializer_write_file()`: Method which wraps `serializer_content_type()`, but orchestrates creating, writing serialized content to, reading from, and removing a temp file. (#660)

### Body parsing

* Added support for request body parsing (@meztez, #532)

* New request body parsers
  * `parser_csv()`: Parse request body as a commas separated value (#584)
  * `parser_json()`: Parse request body as JSON (@meztez, #532)
  * `parser_multi()`: Parse multi part request bodies (@meztez, #532) and (#663)
  * `parser_octet()`: Parse request body octet stream (@meztez, #532)
  * `parser_form()`: Parse request body as form input (@meztez, #532)
  * `parser_rds()`: Parse request body as RDS file input (@meztez, #532)
  * `parser_text()`: Parse request body plain text (@meztez, #532)
  * `parser_tsv()`: Parse request body a tab separated value (#584)
  * `parser_yaml()`: Parse request body as `yaml` (#584)
  * `parser_none()`: Do not parse the request body (#584)
  * `parser_yaml()`: Parse request body (@meztez, #556)
  * `parser_feather()`: Parse request body using `feather` (#626)
  * Pseudo parser named `"all"` to allow for using all parsers. (Not recommended in production!) (#584)

* The parsed request body values is stored at `req$body`. (#663)

* If `multipart/*` content is parsed, `req$body` will contain named output from `webutils::parse_multipart()` and add the parsed value to each part. Look here for access to all provided information (e.g., `name`, `filename`, `content_type`, etc). In addition, `req$argsBody` (which is used for route argument matching) will contain a named reduced form of this information where `parsed` values (and `filename`s) are combined on the same `name`. (#663)

### Visual Documentation

* Generalize user interface integration. Plumber can now use other OpenAPI compatible user interfaces like `RapiDoc` (https://github.com/mrin9/RapiDoc) and `Redoc` (https://github.com/Redocly/redoc). Pending CRAN approbations, development R packages are available from https://github.com/meztez/rapidoc/ and https://github.com/meztez/redoc/. (@meztez, #562)

* Changed Swagger UI to use [swagger](https://github.com/rstudio/swagger) R package to display the swagger page. (#365)

* Added support for swagger for mounted routers (@bradleyhd, #274).

## Security improvements

* Secret session cookies are now encrypted using `sodium`.
  All prior `req$session` information will be lost.
  Please see `?session_cookie` for more information.
  (#404)

* Session cookies set the `HttpOnly` flag by default to mitigate cross-site scripting (XSS).
  Please see `?session_cookie` for more information.
  (#404)

* Wrap `jsonlite::fromJSON` to ensure that `jsonlite` never reads
  input as a remote address (such as a file path or URL) and attempts to parse
  that. The only known way to exploit this behavior in plumber unless an
  API were using encrypted cookies and an attacker knew the encryption key in
  order to craft arbitrary cookies. (#325)

## Breaking changes

* When `plumb()`ing a file (or `Plumber$new(file)`), the working directory is set to the file's directory before parsing the file. When running the Plumber API, the working directory will be set to file's directory before running.(#631)

* Plumber's OpenAPI Specification is now defined using
  [OpenAPI 3](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.3.md),
  upgrading from Swagger Specification. (#365)

* Plumber router `$run()` method arguments `swagger`, `swaggerCallback` and `debug` are now deprecated. User interface and url callback are now enabled by default and managed through Plumber router `$setDocs()`, `$setDocsCallback()`, and `$setDebug()` methods and options `plumber.docs` and `plumber.docs.callback`. (@meztez, #562)

* `plumb()` now returns an object of class `"Plumber"` (previously `"plumber"`). To check if an object is a Plumber router, use new method `is_plumber()`. (#653)

* `PlumberStatic` objects now have a class of `"PlumberStatic"` (previously `"plumberstatic"`). (#653)

* The source files used in plumber **must use** the UTF-8 encoding if they contain
  non-ASCII characters (@shrektan, #312,
  #328).

* `options(plumber.debug)` is not set anymore when running the plumber application. Instead retrieve the debug value using `$getDebug()` on the Plumber router directly. Ex: `function(req, res) { req$pr$getDebug() }`. (#639)

* `PlumberEndpoint`'s method `$exec()` now has a shape of `$exec(req, res)` (vs `$exec(...)`).  This allows for fine tune control over the arguments being sent to the endpoint function.

* When creating a `PlumberFilter` or `PlumberEndpoint`, an error will be thrown if `expr` does not evaluate to a function. (#666)

## Deprecations

* Shorthand serializers are now deprecated. `@html`, `@json`, `@png`, `@jpeg`, `@svg` should be replaced with the `@serializer` syntax. Ex: `@serializer html` or `@serializer jpeg` (#630)

* `plumber` R6 object has been deprecated and renamed to `Plumber`. `PlumberStatic`'s `inherit`ed class has been updated to `Plumber`. (#653)
* `hookable` R6 object has been deprecated and renamed to `Hookable`.  `Plumber` and `PlumberStep`'s `inherit`ed class has been updated to `Hookable`. (#653)

* `addSerializer()` has been deprecated in favor of `register_serializer()` (#584)
* `getCharacterSet()` has been deprecated in favor of `get_character_set()` (#651)
* `randomCookieKey()` has been deprecated in favor of `random_cookie_key()` (#651)
* `sessionCookie()` has been deprecated in favor of `session_cookie()` (#651)

* DigitalOcean helper functions are now defunct (`do_*()`). The functionality and documentation on how to deploy to DigitalOcean has been moved to [`plumberDeploy`](https://github.com/meztez/plumberDeploy) (by @meztez) (#649)


## Minor new features and improvements

* Documentation is updated and now presented using `pkgdown` (#570)

* New hex logo! Thank you @allisonhorst ! (#570)

* Added helper method `is_plumber(pr)` to determine if an object is a Plumber router. (#653)

* Added support for the `SameSite` Cookie attribute. (@chris-dudley, #640)

* When calling `include_file()`, the `content_type` is automatically inferred from the file extension if `content_type` is not provided. (#631)

* When `plumb()`ing a file, arguments supplied to parsers and serializers may be values defined earlier in the file. (@meztez, #620)

* Updated Docker files. New Docker repo is now [`rstudio/plumber`](https://hub.docker.com/r/rstudio/plumber/tags). Updates heavily inspired from @mskyttner (#459). (#589)

* Support HTTP 405 Code. (@meztez, #554)

* Attached the Plumber router to the incoming request object at `req$pr`. (@meztez, #554)

* Documented plumber options. Added `options_plumber()`. (@meztez, #555)

* Update documentation on R6 objects (@meztez, #530)

* Fix `plumb()` function when `plumb()`ing a directory so that `plumber.R` is not a requirement if a valid `entrypoint.R` file is found. (@blairj09, #471).

* If cookie information is too large (> 4093 bytes), a warning will be displayed. (#404)

* Added new shorthand types for url parameters. (@byzheng, #388)

* Plumber files are now only evaluated once.  Prior plumber behavior sourced endpoint functions twice and non-endpoint code blocks once. (#328)

* Improve speed of `canServe()` method of the `PlumberEndpoint` class (@atheriel, #484)

* Get more file extension content types using the `mime` package. (#660)

* Endpoints that produce images within a `promises::promise()` will now use the expected graphics device. (#669)

## Bug fixes

* Handle plus signs in URI as space characters instead of actual plus signs (@meztez, #618)

* Paths that are missing a leading `/` have a `/` prepended to the path location. (#656)
* Fix possible bugs due to mounted routers without leading slashes (@atheriel, #476 #501).

* Modified images serialization to use content-type serializer. Fixes issue with images pre/postserialize hooks (@meztez, #518).

* Fix bug preventing error handling when a serializer fails (@antoine-sachet, #490)

* Fix URL-decoding of query parameters and URL-encoding/decoding of cookies. Both now use `httpuv::decodeURIComponent` instead of `httpuv::decodeURI`. (@antoine-sachet, #462)

* Fixed bug where functions defined earlier in the file could not be found when `plumb()`ing a file.  (#416)

* A multiline request body is now collapsed to a single line (@robertdj, #270 #297).

* Bumped version of httpuv to >= 1.4.5.9000 to address an unexpected segfault (@shapenaji, #289)

* Date response header is now supplied by httpuv and not plumber. Fixes non standard date response header issues when using different locales. (@shrektan, #319, #380)

* Due to incompatibilities with `multipart` body values, `req$postBody` will only be calculated if accessed. It is strongly recommended to use `req$bodyRaw` when trying to create content from the input body. (#665)



# plumber 0.4.6

* BUGFIX: Hooks that accept a `value` argument (`postroute`, `preserialize`,
  and `postserialize`) now modify the incoming value as documented.
* BUGFIX: The `postserialize` hook is now given the serialized data as its
  `value` parameter.
* BUGFIX: properly handle cookie expiration values (#216).
* Add support for tags in Swagger docs (#230).
* Optional `swaggerCallback` parameter for `run()` to supply a callback function
  for reporting the url for swagger page.
* Add [RStudio Project Template](https://rstudio.github.io/rstudio-extensions/rstudio_project_templates.html) to package.


# plumber 0.4.4

* Support Expiration, HTTPOnly, and Secure flags on cookies (#87). **EDIT**:
  see #216 which prevented
  expiration from working.
* BUGFIX: properly handle named query string and post body arguments in
  mounted subrouters.
* Added support for static sizing of images. `@png` and `@jpeg` now accept a
  parenthetical list of arguments that will be passed into the `png()` or
  `jpeg()` call. This enables annotations like
  `#' @png (width = 200, height=500)`.
* Enable `ByteCompile` flag
* Set working directory for DigitalOcean APIs.
* Respect `setErrorHandler`
* BUGFIX: export `PlumberStatic`
* Case-insensitive matching on `plumber.r` and `entrypoint.r` when
  `plumb()`ing a directory.
* Support query strings with keys that appear more than once
  (#165)
* Fix the validation error warning at the bottom of deployed Swagger files
  which would have appeared any time your `swagger.json` file was hosted in
  such a way that a hosted validator service would not have been able to access
  it. For now we just suppress validation of swagger.json files. (#149)
* Support for floating IPs in DNS check that occurs in `do_configure_https()`
* Make adding swap file idempotent in `do_provision()` so you can now call that
  on a single droplet multiple times.
* Support an `exit` hook which can define a function that will be
  evaluated when the API is interrupted. e.g.
  `pr <- plumb("plumber.R"); pr$registerHook("exit", function(){ print("Bye bye!") })`
* Fixed bug in which a single function couldn't support multiple paths for a
  single verb (#203).
* Support negative numbers in numeric path segments (#212)
* Support `.` in string path segments


# plumber 0.4.2

* Development version for 0.4.2. Will be working to move to even/odd release
  cycles, but I had prematurely bumped to 0.4.0 so that one might get skipped,
  making the next CRAN release 0.4.2.


# plumber 0.4.0

* BREAKING: Listen on localhost instead of listening publicly by default.
* BREAKING: We no longer set the `Access-Control-Allow-Origin` HTTP header to
  `*`. This was previously done for convenience but we've decided to prioritize
  security here by removing this default. You can still add this header to any
  route you want to be accessible from other origins.
* BREAKING: Listen on a random port by default instead of always on 8000. This
  can be controlled using the `port` parameter in `run()`, or by setting the
  `plumber.port` option.
* BREAKING: Removed `PlumberProcessor` class and replaced with a notion of
  hooks. See `registerHook` and `registerHooks` on the Plumber router.
* BREAKING: `addGlobalProcessor` method on Plumber routers now takes a list
  which are added as hooks instead of a Processor. Note that `sessionCookie`
  has also been updated to behave accordingly, meaning that the convention of
  `pr$addGlobalProcessor(sessionCookie("secret", "cookieName"))` will continue
  to work for this release.
* BREAKING: `sessionCookie` now returns a list instead of a Processor. Note
  that `addGlobalProcessor` has also been updated to behave accordingly,
  meaning that the convention of
  `pr$addGlobalProcessor(sessionCookie("secret", "cookieName"))` will continue
  to work for this release.
* DEPRECATION: Deprecated the `addAssets` method on Plumber routers. Use
  `PlumberStatic` and the `mount` method to attach a static router.
* DEPRECATION: Deprecated the `addEndpoint` method in favor of the `handle`
  method for Plumber routers. Removed support for the `processors`, `params`,
  and `comments` parameters are no longer supported.
* DEPRECATION: Deprecated the `addFilter` method on Plumber routers in favor
  of the new `filter` method. Removed support for the processor parameter.
* DEPRECATION: Deprecated the `addGlobalProcessor` method on Plumber routers.
* The undocumented `setDefaultErrorHandler` method on Plumber routers now takes
  a function that returns the error handler function. The top-level function
  takes a single param named `debug` which is managed by the `debug` parameter
  in the `run()` method.
* Added support for `OPTIONS` HTTP requests via the `@options` annotation.
* Add support for `entrypoint.R` when `plumb()`ing a directory. If this file
  exists, it is expected to return a Plumber router representing the API
  contained in this directory. If it doesn't exist, the behavior is unaltered.
  If both `plumber.R` and `entrypoint.R` exist, `entrypoint.R` takes precedence.
* `plumb()` the current directory by default if no arguments are provided.
* Added a `debug` parameter to the `run` method which can be set to `TRUE` in
  order to get more insight into your API errors.


# plumber 0.3.3

* `plumb()` now accepts an argument `dir`, referring to a directory containing
  `plumber.R`, which may be provided instead of `file`.


# plumber 0.3.2

* Introduced the `do_provision()`, `do_deploy_api()`, `do_remove_api()` and
  `do_configure_https()` functions to provision and manage your APIs on a
   cloud server running on DigitalOcean.
* `source()` the referenced R file to plumb inside of a new environment that
  inherits directly from the GlobalEnv. This provides more explicit control over
  exactly how this environment should behave.
* Added `@serializer htmlwidget` to support rendering and returning a
  self-contained htmlwidget from a plumber endpoint.
* Properly handle cookies with no value. (#88)
* Don't convert `+` character in a query string to a space.


# plumber 0.3.1

* Add a method to consume JSON on post (you can still send a query string in
  the body of a POST request as well).


# plumber 0.3.0

* BREAKING CHANGE: serializer factories are now registered instead of the
  serializer themselves. Thus, `addSerializer()` now expects a function that
  returns a serializer, and `Response$new()` now expects a serializer itself
  rather than a character string naming a serializer. Internally it is the
  serializer itself that is attached to the response rather than the name of
  the serializer. This allows for a serializer to customize its behavior.
* Accept an additional argument on the `@serializer` annotation -- R code that
  will be passed in as an argument to the serializer factory. See example
  `09-content-type`.


# plumber 0.2.4

* Add a filter which parses and sets req$cookies to be a list corresponding to
  the cookies provided with the request.
* Responses can set multiple cookies
* Bug Fix: convert non-character arguments in setCookie to character before URL-
  encoding.


# plumber 0.2.3

* Set options(warn=1) during execution of user code so that warnings are
  immediately visible in the console, rather than storing them until the server
  is stopped.


# plumber 0.2.2

* Add `sessionCookie` function to define a processor that can be used as a
  globalProcessor on a router to encrypt values from req$session and store them
  as an encrypted cookie in on the user's browser.
* Added `setCookie` method to response which (primitively) allows you to set
  a cookie to be included in the response.
* Add `addGlobalProcessor` method on `plumber` class to support a processor that
  runs a processor only a single time, before and then after all other filters
  and the endpoint.
* Document all public params so CHECK passes


# plumber 0.2.1

* Add more `roxygen2` documentation for exported functions
* Remove the warning in the README as the API seems to be stabilizing.


# plumber 0.2.0

* BREAKING: Changed variable-path routing to use bracketed format instead of
  just a colon.
* BREAKING: Renamed `PlumberRouter` R6 object to just `Plumber`.
* Support `addEndpoint()` and `addFilter()` on the `Plumber` object.
* Added support for the `#*` prefix.


# plumber 0.1.0

* Initial Release
