在表达式语言中转义JavaScript [英] Escape JavaScript in Expression Language
问题描述
有时，我需要在JSF页面中使用EL渲染JavaScript变量。
例如
< script> var foo ='＃{bean.foo}';< / script>
或
< h：xxx ... onclick =foo（'＃{bean.foo}'）/>
当EL表达式计算为包含JS特殊字符的字符串（如撇号和换行。如何逃脱？
您可以使用 Apache Commons Lang 3.x StringEscapeUtils＃escapeEcmaScript（） 在EL中的方法
首先创建一个 /WEB-INF/functions.taglib.xml ，如下所示：
<？xml version =1.0encoding =UTF-8？>
< facelet-taglib
xmlns =http://java.sun.com/xml/ns/javaee
xmlns：xsi =http://www.w3.org / 2001 / XMLSchema-instance
xsi：schemaLocation =http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facelettaglibrary_2_0 .xsd
version =2.0>
< namespace> http：//example.com/functions< / namespace>
< function>
< name> escapeJS< / name>
< function-class> org.apache.commons.lang3.StringEscapeUtils< / function-class>
< function-signature> java.lang.String escapeEcmaScript（java.lang.String）< / function-signature>
< / function>
< / taglib>
然后在 /WEB-INF/web.xml 如下：
< context-param>
< param-name> javax.faces.FACELETS_LIBRARIES< / param-name>
< param-value> /WEB-INF/functions.taglib.xml< / param-value>
< / context-param>
然后你可以使用它如下：
< pre class =lang-xml prettyprint-override>
< html ... xmlns：func =http://example.com/functions>
...
< script> var foo ='＃{func：escapeJS（bean.foo）}';< / script>
...
< h：xxx ... onclick =foo（'＃{func：escapeJS（bean.foo）}'）/>
或者，如果您碰巧已经使用JSF实用程序库 OmniFaces ，那么你也可以使用它的内置 ：escapeJS（） 功能：
; html ... xmlns：of =http://omnifaces.org/functions>
...
< script> var foo ='＃{of：escapeJS（bean.foo）}';< / script>
...
< h：xxx ... onclick =foo（'＃{of：escapeJS（bean.foo）}'）/>
Sometimes, I need to render a JavaScript variable using EL in a JSF page.
E.g.
<script>var foo = '#{bean.foo}';</script>
or
<h:xxx ... onclick="foo('#{bean.foo}')" />
This fails with a JS syntax error when the EL expression evaluates to a string containing JS special characters such as apostrophe and newline. How do I escape it?
You can use Apache Commons Lang 3.x StringEscapeUtils#escapeEcmaScript() method for this in EL.
First create a /WEB-INF/functions.taglib.xml which look like this:
<?xml version="1.0" encoding="UTF-8"?>
<facelet-taglib
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facelettaglibrary_2_0.xsd"
version="2.0">
<namespace>http://example.com/functions</namespace>
<function>
<name>escapeJS</name>
<function-class>org.apache.commons.lang3.StringEscapeUtils</function-class>
<function-signature>java.lang.String escapeEcmaScript(java.lang.String)</function-signature>
</function>
</taglib>
Then register it in /WEB-INF/web.xml as follows:
<context-param>
<param-name>javax.faces.FACELETS_LIBRARIES</param-name>
<param-value>/WEB-INF/functions.taglib.xml</param-value>
</context-param>
Then you can use it as follows:
<html ... xmlns:func="http://example.com/functions">
...
<script>var foo = '#{func:escapeJS(bean.foo)}';</script>
...
<h:xxx ... onclick="foo('#{func:escapeJS(bean.foo)}')" />
Alternatively, if you happen to already use the JSF utility library OmniFaces, then you can also just use its builtin of:escapeJS() function:
<html ... xmlns:of="http://omnifaces.org/functions">
...
<script>var foo = '#{of:escapeJS(bean.foo)}';</script>
...
<h:xxx ... onclick="foo('#{of:escapeJS(bean.foo)}')" />
这篇关于在表达式语言中转义JavaScript的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
