vm.runInContext(code, contextifiedObject[, options])
code
<string> 将被编译和运行的 JavaScript 代码。contextifiedObject
<Object> 一个被上下文隔离化过的对象,会在code
被编译和执行之后充当global
对象。options
<Object> | <string>filename
<string> 定义供脚本生成的堆栈跟踪信息所使用的文件名。默认值:'evalmachine.<anonymous>'
。lineOffset
<number> 定义脚本生成的堆栈跟踪信息所显示的行号偏移。默认值:0
。columnOffset
<number> 定义脚本生成的堆栈跟踪信息所显示的列号偏移。默认值:0
。displayErrors
<boolean> 当值为true
的时候,假如在解析代码的时候发生错误Error
,引起错误的行将会被加入堆栈跟踪信息。默认值:true
。timeout
<integer> 定义在被终止执行之前此code
被允许执行的最大毫秒数。假如执行被终止,将会抛出一个错误Error
。该值必须是严格正整数。breakOnSigint
<boolean> 若值为true
,接收到SIGINT
(Ctrl+C)会终止执行并抛出Error
。 通过process.on('SIGINT')
方法所设置的消息响应机制在代码被执行时会被屏蔽,但代码被终止后会被恢复。 默认值:false
。cachedData
<Buffer> | <TypedArray> | <DataView> 为源码提供一个可选的存有 V8 代码缓存数据的Buffer
、TypedArray
或TypedArray
。 如果提供了,则cachedDataRejected
的值将会被设为要么为true
要么为false
,这取决于 v8 引擎对数据的接受状况。produceCachedData
<boolean> 当值为true
且cachedData
不存在的时候,V8 将会试图为code
生成代码缓存数据。 一旦成功,则一个有 V8 代码缓存数据的Buffer
将会被生成和储存在返回的vm.Script
实例的cachedData
属性里。cachedDataProduced
的值会被设置为true
或者false
,这取决于代码缓存数据是否被成功生成。 不推荐使用此选项,而应该使用script.createCachedData()
。默认值:false
。importModuleDynamically
<Function> 在调用import()
时评估此模块期间调用。 如果未指定此选项,则对import()
的调用将拒绝ERR_VM_DYNAMIC_IMPORT_CALLBACK_MISSING
。 此选项是实验的模块的 API 的一部分,不应被视为稳定。specifier
<string> 传给import()
的说明符。module
<vm.Module>- 返回: <Module Namespace Object> | <vm.Module> 返回
vm.Module
以利用错误跟踪,并避免出现包含then
函数导出的命名空间问题。
- 返回: <any> 脚本中执行的最后一个语句的结果。
vm.runInContext()
方法会编译 code
,然后在指定的 contextifiedObject
的上下文里执行它并返回其结果。
被执行的代码无法获取本地作用域。
contextifiedObject
必须是事先被 vm.createContext()
方法上下文隔离化过的对象。
如果 options
是字符串,则它指定文件名。
以下例子使用一个单独的上下文隔离化过的对象来编译并运行几个不同的脚本:
const vm = require('vm');
const contextObject = { globalVar: 1 };
vm.createContext(contextObject);
for (let i = 0; i < 10; ++i) {
vm.runInContext('globalVar *= 2;', contextObject);
}
console.log(contextObject);
// 打印: { globalVar: 1024 }
code
<string> The JavaScript code to compile and run.contextifiedObject
<Object> The contextified object that will be used as theglobal
when thecode
is compiled and run.options
<Object> | <string>filename
<string> Specifies the filename used in stack traces produced by this script. Default:'evalmachine.<anonymous>'
.lineOffset
<number> Specifies the line number offset that is displayed in stack traces produced by this script. Default:0
.columnOffset
<number> Specifies the column number offset that is displayed in stack traces produced by this script. Default:0
.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
, receivingSIGINT
(Ctrl+C) will terminate execution and throw anError
. Existing handlers for the event that have been attached viaprocess.on('SIGINT')
are disabled during script execution, but continue to work after that. Default:false
.cachedData
<Buffer> | <TypedArray> | <DataView> Provides an optionalBuffer
orTypedArray
, orDataView
with V8's code cache data for the supplied source. When supplied, thecachedDataRejected
value will be set to eithertrue
orfalse
depending on acceptance of the data by V8.produceCachedData
<boolean> Whentrue
and nocachedData
is present, V8 will attempt to produce code cache data forcode
. Upon success, aBuffer
with V8's code cache data will be produced and stored in thecachedData
property of the returnedvm.Script
instance. ThecachedDataProduced
value will be set to eithertrue
orfalse
depending on whether code cache data is produced successfully. This option is deprecated in favor ofscript.createCachedData()
. Default:false
.importModuleDynamically
<Function> Called during evaluation of this module whenimport()
is called. If this option is not specified, calls toimport()
will reject withERR_VM_DYNAMIC_IMPORT_CALLBACK_MISSING
. This option is part of the experimental modules API. We do not recommend using it in a production environment.specifier
<string> specifier passed toimport()
script
<vm.Script>- Returns: <Module Namespace Object> | <vm.Module> Returning a
vm.Module
is recommended in order to take advantage of error tracking, and to avoid issues with namespaces that containthen
function exports.
- Returns: <any> the result of the very last statement executed in the script.
The vm.runInContext()
method compiles code
, runs it within the context of
the contextifiedObject
, then returns the result. Running code does not have
access to the local scope. The contextifiedObject
object must have been
previously contextified using the vm.createContext()
method.
If options
is a string, then it specifies the filename.
The following example compiles and executes different scripts using a single contextified object:
const vm = require('vm');
const contextObject = { globalVar: 1 };
vm.createContext(contextObject);
for (let i = 0; i < 10; ++i) {
vm.runInContext('globalVar *= 2;', contextObject);
}
console.log(contextObject);
// Prints: { globalVar: 1024 }