{"id":818,"date":"2012-08-24T12:29:44","date_gmt":"2012-08-24T10:29:44","guid":{"rendered":"http:\/\/hasselba.ch\/blog\/?p=818"},"modified":"2012-08-24T12:31:25","modified_gmt":"2012-08-24T10:31:25","slug":"ssjs-whats-this","status":"publish","type":"post","link":"https:\/\/hasselba.ch\/blog\/?p=818","title":{"rendered":"SSJS: What’s „this“?"},"content":{"rendered":"

In Serverside JavaScript the keyword this<\/em> always refers to the \u201cowner\u201d of the function\u00a0which is executing,\u00a0 or rather, to the object that a function is a method of.<\/p>\n

This means f.e. that this<\/em> refers to the UIComponent which contains the SSJS code. If you add a label to a XPage and compute the value…<\/p>\n

<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n<xp:view xmlns:xp=\"http:\/\/www.ibm.com\/xsp\/core\">\r\n   <xp:label id=\"label1\">\r\n\u00a0\u00a0\u00a0\u00a0\u00a0 <xp:this.value>\r\n\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0 <![CDATA[#{javascript:return this;}]]>\r\n      <\/xp:this.value>\r\n   <\/xp:label>\r\n<\/xp:view><\/pre>\n
… this<\/em> will always return the current corresponding instance of the XspOutputLabel:<\/p>\n
\"\"<\/p>\n
But if you are inside a function this<\/em> will return the current JavaScript object instead:<\/p>\n
<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n<xp:view xmlns:xp=\"http:\/\/www.ibm.com\/xsp\/core\">\r\n\r\n\u00a0\u00a0 <xp:label id=\"label1\">\r\n\u00a0\u00a0\u00a0\u00a0\u00a0 <xp:this.value>\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <![CDATA[#{javascript:\r\n\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 \u00a0var arr = [1, 2];\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 function callMe(){\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 var obj = this;\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 for( var p in obj ){\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 print( p + \" -> \" + obj[p] + \" [\" + typeof(obj[p]) + \"]\" );\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }\u00a0\u00a0 \u00a0\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 callMe()\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }]]>\r\n\u00a0\u00a0\u00a0\u00a0\u00a0 <\/xp:this.value>\r\n\u00a0\u00a0 <\/xp:label>\r\n\r\n<\/xp:view><\/pre>\n
The result on the console looks like this:<\/p>\n
\"\"<\/p>\n
If you are using call<\/em> or apply<\/em>, you can overwrite the this object:<\/p>\n
<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n<xp:view xmlns:xp=\"http:\/\/www.ibm.com\/xsp\/core\">\r\n\r\n\u00a0\u00a0 <xp:label id=\"label1\">\r\n\u00a0\u00a0\u00a0\u00a0\u00a0 <xp:this.value>\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <![CDATA[#{javascript:\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 function callMe(){\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 println(this);\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 for( p in arguments ){\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 println( arguments[p] );\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 } \r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }\r\n\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 callMe.call(\"1\",\"2\",\"3\");\r\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }]]>\r\n\u00a0\u00a0\u00a0\u00a0\u00a0 <\/xp:this.value>\r\n\u00a0\u00a0 <\/xp:label>\r\n<\/xp:view><\/pre>\n
Now this<\/em> is set to „1<\/em>„. The arguments are „2<\/em>“ and „3<\/em>„, as you can see on the server console:<\/p>\n
\"\"<\/p>\n","protected":false},"excerpt":{"rendered":"
In Serverside JavaScript the keyword this always refers to the \u201cowner\u201d of the function\u00a0which is executing,\u00a0 or rather, to the object that a function is a method of. This means f.e. that this refers to the UIComponent which contains the … Weiterlesen →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,9,76,74],"tags":[7,4,5,3],"class_list":["post-818","post","type-post","status-publish","format-standard","hentry","category-allgemein","category-javascript","category-ssjs","category-xpages","tag-domino","tag-js","tag-ssjs","tag-xpages"],"_links":{"self":[{"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=\/wp\/v2\/posts\/818","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=818"}],"version-history":[{"count":13,"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=\/wp\/v2\/posts\/818\/revisions"}],"predecessor-version":[{"id":831,"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=\/wp\/v2\/posts\/818\/revisions\/831"}],"wp:attachment":[{"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=818"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=818"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hasselba.ch\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=818"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}