script.runInNewContext([contextObject[, options]])
contextObject
<Object> 将被上下文隔离化的对象。 如果为undefined
,则将创建新的对象。options
<Object>-
displayErrors
<boolean> 当为true
时,如果编译code
时出现Error
,则导致错误的代码行会附加到堆栈跟踪中。 默认值:true
。 -
timeout
<integer> 指定终止执行前执行code
的毫秒数。 如果执行终止,则将抛出Error
。 此值必须是严格的正整数。 -
breakOnSigint
<boolean>如果执行终止,则将抛出
Error
。 默认值:false
。 -
contextName
<string> 新创建的上下文的可读名称。 默认值:'VM Context i'
, 其中i
是创建的上下文的升序数字索引。 -
contextOrigin
<string> 对应于新创建的用于显示目的的上下文的来源。 来源的格式应该像 URL,但只有协议、主机和端口(如果需要),就像URL
对象的url.origin
属性的值。 最值得注意的是,该字符串应省略尾部斜杠,因为它表示路径。 默认值:''
。 -
contextCodeGeneration
<Object>
-
- 返回: <any> 脚本中执行的最后一条语句的结果。
首先对给定的 contextObject
进行上下文隔离化,在创建的上下文中运行 vm.Script
对象包含的编译代码,并返回结果。
运行代码无权访问本地作用域。
以下示例编译设置全局变量的代码,然后在不同的上下文中多次执行代码。
全局变量设置并包含在每个单独的 context
中。
const vm = require('vm');
const script = new vm.Script('globalVar = "set"');
const contexts = [{}, {}, {}];
contexts.forEach((context) => {
script.runInNewContext(context);
});
console.log(contexts);
// 打印: [{ globalVar: 'set' }, { globalVar: 'set' }, { globalVar: 'set' }]
contextObject
<Object> An object that will be contextified. Ifundefined
, a new object will be created.options
<Object>displayErrors
<boolean> Whentrue
, if anError
occurs while compiling thecode
, the line of code causing the error is attached to the stack trace. Default:true
.timeout
<integer> Specifies the number of milliseconds to executecode
before terminating execution. If execution is terminated, anError
will be thrown. This value must be a strictly positive integer.breakOnSigint
<boolean> Iftrue
, the execution will be terminated whenSIGINT
(Ctrl+C) is received. Existing handlers for the event that have been attached viaprocess.on('SIGINT')
will be disabled during script execution, but will continue to work after that. If execution is terminated, anError
will be thrown. Default:false
.contextName
<string> Human-readable name of the newly created context. Default:'VM Context i'
, wherei
is an ascending numerical index of the created context.contextOrigin
<string> Origin corresponding to the newly created context for display purposes. The origin should be formatted like a URL, but with only the scheme, host, and port (if necessary), like the value of theurl.origin
property of aURL
object. Most notably, this string should omit the trailing slash, as that denotes a path. Default:''
.contextCodeGeneration
<Object>
- Returns: <any> the result of the very last statement executed in the script.
First contextifies the given contextObject
, runs the compiled code contained
by the vm.Script
object within the created context, and returns the result.
Running code does not have access to local scope.
The following example compiles code that sets a global variable, then executes
the code multiple times in different contexts. The globals are set on and
contained within each individual context
.
const vm = require('vm');
const script = new vm.Script('globalVar = "set"');
const contexts = [{}, {}, {}];
contexts.forEach((context) => {
script.runInNewContext(context);
});
console.log(contexts);
// Prints: [{ globalVar: 'set' }, { globalVar: 'set' }, { globalVar: 'set' }]