How to set the JSTL variable value in javascript

Question

How to set the JSTL variable value in java script    lt script gt    function function1           var val1   document getElementById  userName   value      lt c set var  user  value     gt      how do i set val1 here           lt  script gt    How do I set the  user  variable  JSTL  value from  val1   Java script

User · Answer

You have to use the normal string concatenation but you have to make sure the value is a Valid XML string  you will find a good practice to write XML in this source http   oreilly com pub h 2127  or if you like you can use an API in javascript to write XML as helma for example

User · Answer

This variable can be set using value    val1   inside c set if you have used jquery in your system

User · Answer

It is not possible because they are executed in different environments  JSP at server side  JavaScript at client side   So they are not executed in the sequence you see in your code   var val1   document getElementById  userName   value     lt c set var  user  value     gt      how do i set val1 here     Here JSTL code is executed at server side and the server sees the JavaScript Html codes as simple texts  The generated contents from JSTL code  if any  will be rendered in the resulting HTML along with your other JavaScript HTML codes  Now the browser renders HTML along with executing the Javascript codes  Now remember there is no JSTL code available for the browser   Now for example    lt script type  text javascript  gt   lt c set var  message  value  Hello   gt   var message     lt c out value    message    gt     lt  script gt    Now for the browser  this content is rendered    lt script type  text javascript  gt  var message    Hello    lt  script gt    Hope this helps

User · Answer

As an answer I say No  You can only get values from jstl to javascript  But u can display the user name using javascript itself  Best ways are here  To display user name  if u have html like   lt div id  uName  gt  lt  div gt    You can display user name as follows   var val1   document getElementById  userName   value  document getElementById  uName   innerHTML   val1    To get data from jstl to your javascript     var userName     lt c out value    user    gt      here   user  is the data you get as response from backend    Asigning number array length  var arrayLength    lt c out value    details size      gt     Advanced   function advanced        var values   new Array         lt c if test    empty details users   gt         values push  No user found          lt  c if gt                 lt c if test     empty details users   gt           lt c forEach var  user  items    details users   varStatus  stat  gt              values push    user name                 lt  c forEach gt       lt   c if gt      alert  values 0    values 0

User · Answer

Just don t  Don t write code with code  Write a JSON object or a var somewhere but for the love of a sensible HTTP divide  don t write JavaScript functions or methods hardcoded with vars properties provided by JSTL  Generating JSON is cool  It ends there or your UI dev hates you   Imagine if you had to dig into JavaScript to find something that was setting parameters in the middle of a class that originated on the client-side  It s awful  Pass data back and forth  Handle the data  But don t try to generate actual code

User · Answer

lt script       function       var someJsVar     lt c out value    someJstLVarFromBackend    gt          lt  script gt    This works even if you dont have a hidden non-hidden input field set somewhere in the jsp

User · Answer

You can save the whole jstl object as a Javascript object by converting the whole object to json  It is possible by Jackson in java   import com fasterxml jackson databind ObjectMapper   public class JsonUtil     public static String toJsonString Object obj         ObjectMapper objectMapper           jackson object mapper       return objectMapper writeValueAsString obj             WEB-INF tags util-functions tld    lt  xml version  1 0  encoding  ISO-8859-1    gt   lt taglib xmlns  http   java sun com xml ns j2ee     xmlns xsi  http   www w3 org 2001 XMLSchema-instance     xsi schemaLocation  http   java sun com xml ns j2ee http   java sun com xml ns javaee web-jsptaglibrary 2 1 xsd     version  2 1  gt       lt tlib-version gt 1 0 lt  tlib-version gt     lt uri gt http   www your url util-functions lt  uri gt      lt function gt         lt name gt toJsonString lt  name gt         lt function-class gt your package JsonUtil lt  function-class gt         lt function-signature gt java lang String toJsonString java lang Object  lt  function-signature gt     lt  function gt      lt  taglib gt     web xml   lt jsp-config gt     lt tablib gt       lt taglib-uri gt http   www your url util-functions lt  taglib-uri gt       lt taglib-location gt  WEB-INF tags util-functions tld lt  taglib-location gt     lt  taglib gt   lt  jsp-confi gt    mypage jsp    lt    taglib prefix  uf  uri  http   www your url util-functions    gt     lt script gt     var myJavaScriptObject   JSON parse    uf toJsonString myJstlObject       lt  script gt

User · Answer

one more approach to use   first  define the following somewhere on the page    lt div id  valueHolderId  gt   someValue  lt  div gt    then in JS  just do something similar to  var someValue       valueHolderId   html      it works great for the cases when all scripts are inside  js files and obviously there is no jstl available

[javascript] How to set the JSTL variable value in javascript?

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