[#995] Add clojure.data.xml/alias-uri

feature-xml/babashka/impl/xml.clj

@@ -1,13 +1,48 @@
 (ns babashka.impl.xml
   {:no-doc true}
-  (:require [clojure.data.xml :as xml]
-            [sci.impl.namespaces :refer [copy-var]]
-            [sci.impl.vars :as vars]))
+  (:require [babashka.impl.common :refer [ctx]]
+            [clojure.data.xml :as xml]
+            [sci.core :as sci :refer [copy-var]]
+            [sci.impl.vars]))
 
-(def xns (vars/->SciNamespace 'clojure.data.xml nil))
+(def xns (sci/create-ns 'clojure.data.xml nil))
+
+(defn- clj-ns-name [ns]
+  (cond (instance? sci.impl.vars.SciNamespace ns) (str ns)
+        (keyword? ns) (name ns)
+        :else (str ns)))
+
+(defn alias-uri
+  "Define a Clojure namespace aliases for xmlns uris.
+  This sets up the current namespace for reading qnames denoted with
+  Clojure's ::alias/keywords reader feature.
+
+  ## Example
+  (alias-uri :D \"DAV:\")
+                           ; similar in effect to
+  ;; (require '[xmlns.DAV%3A :as D])
+                           ; but required namespace is auto-created
+                           ; henceforth, shorthand keywords can be used
+  {:tag ::D/propfind}
+                           ; ::D/propfind will be expanded to :xmlns.DAV%3A/propfind
+                           ; in the current namespace by the reader
+  ## Clojurescript support
+  Currently, namespaces can't be auto-created in Clojurescript.
+  Dummy files for aliased uris have to exist. Have a look at `uri-file` and `print-uri-file-command!` to create those."
+  {:arglists '([& {:as alias-nss}])}
+  [& ans]
+  (loop [[a n & rst :as ans] ans]
+    (when (seq ans)
+      #_(assert (<= (count ans)) (pr-str ans))
+      (let [xn (xml/uri-symbol n)
+            al (symbol (clj-ns-name a))]
+        (sci/eval-form @ctx `(create-ns (quote ~xn)))
+        (sci/eval-form @ctx `(alias (quote ~al) (quote ~xn)))
+        (recur rst)))))
 
 (def xml-namespace
   {'aggregate-xmlns (copy-var xml/aggregate-xmlns xns)
+   'alias-uri       (copy-var alias-uri xns)
    'as-qname        (copy-var xml/as-qname xns)
    'cdata           (copy-var xml/cdata xns)
    'element         (copy-var xml/element xns)

test/babashka/main_test.clj

@@ -430,7 +430,9 @@
 (deftest clojure-data-xml-test
   (is (= "<?xml version=\"1.0\" encoding=\"UTF-8\"?><items><item>1</item><item>2</item></items>"
          (bb nil "(let [xml (xml/parse-str \"<items><item>1</item><item>2</item></items>\")] (xml/emit-str xml))")))
-  (is (= "0.0.87-SNAPSHOT" (bb nil "examples/pom_version_get.clj" (.getPath (io/file "test-resources" "pom.xml"))))))
+  (is (= "0.0.87-SNAPSHOT" (bb nil "examples/pom_version_get.clj" (.getPath (io/file "test-resources" "pom.xml")))))
+  (is (= ":xmlns.DAV%3A/propfind"
+         (bb nil "(clojure.data.xml/alias-uri :D \"DAV:\") (str ::D/propfind)"))))
 
 (deftest uberscript-test
   (let [tmp-file (java.io.File/createTempFile "uberscript" ".clj")]