v5

doc/constrain/constrain.xq

@@ -0,0 +1,29 @@
+(:~ 
+ :examples of constrain use
+:)
+import module namespace t="expkg-zone58:image.thumbnailator";
+declare variable $file-base:=file:parent(static-base-uri());
+
+declare variable $src:=file:resolve-path("A17057.jpg",$file-base);
+declare function local:wi($data as xs:base64Binary,$filename as xs:string)
+{
+  file:write-binary(file:resolve-path($filename,$file-base),$data)
+};
+declare function local:constrain($aspect as xs:boolean,$fit as xs:boolean,$exif as xs:boolean)
+{
+<thumbnail>
+  <size width="60" height="200"/>  
+  <constrain aspect="{$aspect}" fit="{$fit}" exif="{$exif}"/>
+</thumbnail>
+};
+let $s:=function($b){if($b) then ".+" else ".-"}
+let $img:= fetch:binary($src)
+let $ft:=(false(),true())
+for $fit in $ft,$aspect in $ft,$exif in $ft
+let $file:=("out.",
+           $s($aspect) , "aspect",
+           $s($fit), "fit",        
+           $s($exif), "exif",
+            ".jpg")=>string-join("")
+let $task:=local:constrain($aspect,$fit,$exif)
+return t:task($img,$task) => local:wi($file)