Native Node Modules

原生Node.js模块由Electron支持，但由于Electron具有与给定Node.js不同的 应用二进制接口 (ABI)(由于使用Chromium的 BoringSL 而不是 OpenSSL 等 差异)，您使用的原生 模块需要为Electron重新编译。 否则，当您尝试运行您的应用程序时， 将会遇到以下的错误：

  1. Error: The module '/path/to/native/module.node'
  2. was compiled against a different Node.js version using
  3. NODE_MODULE_VERSION $XYZ. This version of Node.js requires
  4. NODE_MODULE_VERSION $ABC. Please try re-compiling or re-installing
  5. the module (for instance, using `npm rebuild` or `npm install`).

如何安装原生模块

有多种不同的方法来安装原生模块：

为 Electron 安装并重新编译模块

您可以像其他 Node 项目一样安装模块，然后用 electron-rebuild 包重建这些模块以适配 Electron 。 这个包可以自动识别当前 Electron 版本，为你的应用自动完成下载 headers、重新编译原生模块等步骤。 如果您正在使用 Electron Forge，这个工具将在开发模式和发布时自动使用。

For example, to install the standalone electron-rebuild tool and then rebuild modules with it via the command line:

  1. npm install --save-dev electron-rebuild
  3. # Every time you run "npm install", run this:
  4. ./node_modules/.bin/electron-rebuild
  6. # If you have trouble on Windows, try:
  7. .\node_modules\.bin\electron-rebuild.cmd

For more information on usage and integration with other tools such as Electron Packager, consult the project’s README.

通过 npm 安装

只要设置一些系统环境变量，你就可以通过 npm 直接安装原生模块。

例如，要安装所有Electron的依赖：

  1. # Electron 的版本。
  2. export npm_config_target=1.2.3
  3. # Electron的目标架构, 可用的架构列表请参见
  4. # https://electronjs.org/docs/tutorial/support#supported-platforms
  5. export npm_config_arch=x64
  6. export npm_config_target_arch=x64
  7. # 下载 Electron 的 headers。
  8. export npm_config_disturl=https://electronjs.org/headers
  9. # 告诉 node-pre-gyp 我们是在为 Electron 生成模块。
  10. export npm_config_runtime=electron
  11. # 告诉 node-pre-gyp 从源代码构建模块。
  12. export npm_config_build_from_source=true
  13. # 安装所有依赖，并缓存到 ~/.electron-gyp。
  14. HOME=~/.electron-gyp npm install

为 Electron 手动编译

如果你是一个原生模块的开发人员，想在 Electron 中进行测试， 你可能要手动编译 Electron 模块。 你可以 使用 node-gyp 直接编译：

  1. cd /path-to-module/
  2. HOME=~/.electron-gyp node-gyp rebuild --target=1.2.3 --arch=x64 --dist-url=https://electronjs.org/headers
  • HOME=~/.electron-gyp 设置去哪找头文件
  • --target=1.2.3 设置了 Electron 的版本。
  • --dist-url=...设置了 Electron 的 headers 的下载地址。
  • --arch=x64 设置了该模块为适配64位操作系统而编译。

为Electron的自定义编译手动编译

如果是为一个与公共发行版不匹配的Electron自定义版本编译原生Node模块，需要让npm使用你的Electron自定义版本所对应的Node版本。

  1. npm rebuild --nodedir=/path/to/src/out/Default/gen/node_headers

故障排查

如果您安装了本机模块并发现它无法正常工作，则需要检查以下内容：

  • 当有疑问时，请先执行 electron-rebuild。
  • 确保原生模块与Electron应用程序的目标平台和体系结构兼容。
  • 确保在该模块的binding.gyp中win_delay_load_hook没有被设置为false。
  • 如果升级了 Electron，你通常需要重新编译这些模块。

关于win_delay_load_hook的说明

在Windows上，默认情况下，node-gyp将原生模块与node.dll链接。 然而，在Electron 4.x和更高的版本中，原生模块需要的symbols由electron.exe导出，并且没有node.dll。 In order to load native modules on Windows, node-gyp installs a delay-load hook that triggers when the native module is loaded, and redirects the node.dll reference to use the loading executable instead of looking for node.dll in the library search path (which would turn up nothing). As such, on Electron 4.x and higher, 'win_delay_load_hook': 'true' is required to load native modules.

If you get an error like Module did not self-register, or The specified procedure could not be found, it may mean that the module you’re trying to use did not correctly include the delay-load hook. If the module is built with node-gyp, ensure that the win_delay_load_hook variable is set to true in the binding.gyp file, and isn’t getting overridden anywhere. If the module is built with another system, you’ll need to ensure that you build with a delay-load hook installed in the main .node file. Your link.exe invocation should look like this:

  1.  link.exe /OUT:"foo.node" "...\node.lib" delayimp.lib /DELAYLOAD:node.exe /DLL
  2.      "my_addon.obj" "win_delay_load_hook.obj"

In particular, it’s important that:

  • you link against node.lib from Electron and not Node. If you link against the wrong node.lib you will get load-time errors when you require the module in Electron.
  • you include the flag /DELAYLOAD:node.exe. If the node.exe link is not delayed, then the delay-load hook won’t get a chance to fire and the node symbols won’t be correctly resolved.
  • win_delay_load_hook.obj is linked directly into the final DLL. If the hook is set up in a dependent DLL, it won’t fire at the right time.

See node-gyp for an example delay-load hook if you’re implementing your own.

依赖于 prebuild 的模块

prebuild provides a way to publish native Node modules with prebuilt binaries for multiple versions of Node and Electron.

If the prebuild-powered module provide binaries for the usage in Electron, make sure to omit --build-from-source and the npm_config_build_from_source environment variable in order to take full advantage of the prebuilt binaries.

依赖于 node-pre-gyp 的模块

node-pre-gyp 工具 提供一种部署原生 Node 预编译二进制模块的方法， 许多流行的模块都是使用它。

Sometimes those modules work fine under Electron, but when there are no Electron-specific binaries available, you’ll need to build from source. Because of this, it is recommended to use electron-rebuild for these modules.

If you are following the npm way of installing modules, you’ll need to pass --build-from-source to npm, or set the npm_config_build_from_source environment variable.