vm.runInContext(code, contextifiedObject[, options])
code
<string> 要编译和运行的 JavaScript 代码。contextifiedObject
<Object> 编译和运行code
时将用作global
的上下文隔离化的对象。options
<Object> | <string>filename
<string> 指定此脚本生成的堆栈跟踪中使用的文件名。 默认值:'evalmachine.<anonymous>'
。lineOffset
<number> 指定在此脚本生成的堆栈跟踪中显示的行号偏移量。 默认值:0
。columnOffset
<number> 指定在此脚本生成的堆栈跟踪中显示的第一行列号偏移量。 默认值:0
。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> 如果为true
,则接收SIGINT
(Ctrl+C)将终止执行并抛出Error
。 已通过process.on('SIGINT')
附加的事件的现有句柄在脚本执行期间被禁用,但在此之后继续工作。 默认值:false
。cachedData
<Buffer> | <TypedArray> | <DataView> 为所提供的源提供可选的Buffer
或TypedArray
或DataView
,其中包含 V8 的代码缓存数据。 当提供时,cachedDataRejected
值将设置为true
或false
,具体取决于 V8 对数据的接受程度。produceCachedData
<boolean> 当true
且没有cachedData
存在时,则 V8 将尝试为code
生成代码缓存数据。 当成功后,会生成带有 V8 代码缓存数据的Buffer
并存储在返回的vm.Script
实例的cachedData
属性中。cachedDataProduced
值将设置为true
或false
,这取决于代码缓存数据是否成功生成。 此选项已弃用,支持script.createCachedData()
。 默认值:false
。importModuleDynamically
<Function> 在调用import()
时在评估此模块期间调用。 如果未指定此选项,则调用import()
将使用ERR_VM_DYNAMIC_IMPORT_CALLBACK_MISSING
拒绝。 此选项是实验模块 API 的一部分。 不建议在生产环境中使用它。specifier
<string> 传给import()
的说明符script
<vm.Script>- 返回: <Module Namespace Object> | <vm.Module> 建议返回
vm.Module
以利用错误跟踪,并避免包含then
函数导出的命名空间出现问题。
- 返回: <any> 脚本中执行的最后一条语句的结果。
vm.runInContext()
方法编译 code
,在 contextifiedObject
的上下文中运行它,然后返回结果。
运行代码无权访问本地作用域。
contextifiedObject
对象必须之前已经使用 vm.createContext()
方法上下文隔离化。
如果 options
是字符串,则指定文件名。
以下示例使用单个上下文隔离化的对象编译并执行不同的脚本:
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 first-line 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 }