Ring utilities (ring.util, ring.middleware)

The commonly used pure-function part of Ring's ring-core (1.15.5) and ring-codec (1.3.0) is built in: require it like any library, and the same source runs on every backend. Each namespace is Clojure source shipped with rontolisp and loaded like a project file, so its vars behave like your own (:refer :all, #', function values); a file of the same name on your source path takes precedence, as a source directory precedes a dependency on the classpath. A handler built from them is served by the Ring adapter.

Namespace	Vars
`ring.util.response`	`response` `status` `header` `content-type` `charset` `redirect` `redirect-status-codes` `redirect-after-post` `created` `not-found` `bad-request` `find-header` `get-header` `update-header` `get-charset` `set-cookie` `response?` `file-response` `url-response` `resource-response` `resource-data`
`ring.util.request`	`request-url` `content-type` `content-length` `character-encoding` `urlencoded-form?` `body-string` `path-info` `in-context?` `set-context`
`ring.util.codec`	`url-encode` `url-decode` `percent-encode` `percent-decode` `form-encode` `form-decode` `form-decode-str` `form-decode-map` `assoc-conj` `base64-encode` `base64-decode`
`ring.util.mime-type`	`default-mime-types` `ext-mime-type`
`ring.middleware.params`	`wrap-params` `params-request` `assoc-query-params` `assoc-form-params`
`ring.middleware.keyword-params`	`wrap-keyword-params` `keyword-params-request`
`ring.middleware.content-type`	`wrap-content-type` `content-type-response`

The middleware wrap a handler as in Ring: wrap-params adds :query-params, :form-params (from a application/x-www-form-urlencoded body) and :params, and wrap-keyword-params turns the :params keys that read as keywords into keywords.

Hello, Jürgen!

Files and resources

file-response answers a response whose :body is the java.io.File a path names below :root, with Ring's Content-Length and Last-Modified headers, or nil when there is no such file or the path leaves :root; a directory answers its index.html, index.htm or first index.* unless :index-files? is false. resource-response does the same for a resource of the source path (a file of a directory or an entry of a jar the clojure.java.io resources come from), url-response for a clojure.java.io/resource URL, and resource-data answers the map they read. A jar's resource is a byte stream over its octets, and a directory answers nil. The Ring adapter sends either body as it is. These four load into ring.util.response where a program first names one, so a program naming none carries none of their code.

clojure> (require '[ring.util.response :as response])
nil
clojure> (:headers (response/file-response "a.txt" {:root "www"}))
{"Content-Length" "11", "Last-Modified" "Tue, 02 Jan 2024 03:04:05 GMT"}
clojure> (response/file-response "../secret.txt" {:root "www"})
nil

Not built in

These need a host the WebAssembly backends do not have, and are refused by name when a program names them:

The namespaces ring.middleware.cookies, session, flash, multipart-params, nested-params, not-modified, file, file-info, resource, head and content-length, ring.util.io, time, parsing, test and async, and ring.websocket. ring.adapter.jetty is refused with a pointer to ring.adapter.rontolisp/run-server.

Differences

A charset is named by a string: UTF-8, ISO-8859-1 or US-ASCII, or one of the JDK's aliases for them, in any case; any other name signals an IllegalArgumentException whose message is the name. The default is UTF-8, and malformed input decodes as the JDK replaces it.
body-string is a function of nil, a string, a seq or a stream, not a multimethod a program extends.
content-length reads ASCII digits only (Java's Long/valueOf also takes other scripts' digits).
A canonical path resolves every symbolic link, as the oracle's does, but stays relative where the file's path is (no WASM backend knows the working directory). On both WASM backends a link whose target is absolute is not followed (the WASI host refuses it), so the file is not found.
resource-data has the :file and :jar methods; a URL of another protocol signals No method in resource-data for dispatch value: :http, the words of every multimethod here.