How to pass the value of one variable in the JSP to another in Javascript?

Question

How to pass the value of one variable in the JSP to another in Javascript?

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#1 by (4 votes)

4

I'm trying to set the value of a variable inside a script tag with JSP expression language. I tried this way to check if the value was not empty:

<c:if test="${!empty newsletter.id}">
<script>
   $(function(){
      alert("Entrou no 'if'");
   })
</script>
</c:if>

And it worked, alert was normally displayed (so the newsletter.id attribute is not empty). I then tried to set the value of the variable like this:

<c:if test="${!empty newsletter.id}">
<script>
   $(function(){
      var foo = ${newsletter.content}; /* aqui... */
      alert(foo);
   });
</script>
</c:if>

And then the alert stopped appearing. I even thought it was something because of the ${...} syntax with that of jQuery $(...) and I tried this way:

<c:if test="${!empty newsletter.id}">
<script>
   var foo = ${newsletter.content}; /* tentei fora do document.ready(...) */
   $(function(){
      alert(foo);
   });
</script>
</c:if>

alert did not appear either.

The problem is that it is time to assign the value of newsletter.content to the foo variable in Javascript. How do I assign a value of a JSP variable to a variable within the script tag?

jsp

asked by anonymous 08.05.2015 / 18:18

1 answer

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score 4 · Accepted Answer

var foo = '${newsletter.content}';

When placing the apostrophes, everything in newsetter.content will be placed inside a String. Actually you are using Java to generate Javascript code, so if the content of newsletter.content was "hello world" for example, the way it was would generate the following js code:

var foo = olá mundo;

Now with the apostrophes the generated code is:

var foo = 'olá mundo';