从 JSTL 代码在 javascript 中设置数组值
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/13190306/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Set array values in javascript from JSTL code
提问by Marcus Dryice Koh
I have a code that looks like this:
In AnalyzeUserClient.jsp:
我有一个如下所示的代码：
在 AnalyzeUserClient.jsp 中：
<c:set var="arrayList"><%= (ArrayList<String>)request.getSession().getAttribute("arrayList") %></c:set>
var sessionId = [];
<c:forEach items=${arrayList} var="id">
sessionId.push("${id}"); // add them one at a time, assuming string values
</c:forEach>
However,this line:
但是，这一行：
sessionId.push("${id}");
does not seem to be passing the values into the array "sessionId" (I viewed the source code on browser).So the question is,what can I do to pass the values into the array?
EDIT:I just realised that there are some problems as JSTL is server-side and JavaScript is client-side.So is there a workaround on it?
似乎没有将值传递到数组“sessionId”中（我在浏览器上查看了源代码）。所以问题是，我该怎么做才能将值传递到数组中？
编辑：我刚刚意识到存在一些问题，因为 JSTL 是服务器端而 JavaScript 是客户端。所以有解决方法吗？
回答by JB Nizet
Don't mix EL and scriptlets. In fact, forget about scriptlets completely:
不要混合使用 EL 和 scriptlet。事实上，完全忘记 scriptlet：
var sessionId = [];
<c:forEach items="${sessionScope.arrayList}" var="id">
sessionId.push("${id}");
</c:forEach>
Note though that this will generate invalid JavaScript if one of the IDs happens to contain a double quote. So you'd better JavaScript-escape the IDs before, in your controller. And I would suggest a completely different approach: serialize the list of IDs to a JSON string in your controller, and store this JSON string in request attribute. The JSP page will just need
但请注意，如果 ID 之一恰好包含双引号，这将生成无效的 JavaScript。所以你最好在你的控制器中对 ID 进行 JavaScript 转义。我建议采用完全不同的方法：将 ID 列表序列化为控制器中的 JSON 字符串，并将此 JSON 字符串存储在请求属性中。JSP 页面只需要
var sessionId = ${jsonEncodedSessionIds};
which will translate to the following generated code:
这将转换为以下生成的代码：
var sessionId = ["id1", "id2"];
