如何运行JavaScript文件-V8

Question

I have embedded v8 into my c++ application. Referring https://chromium.googlesource.com/v8/v8/+/master/samples/hello-world.cc I am able to run a javascript. Tested and works fine.

I access the links from my c++ application, download html data, download javascript. Some embedded scripts in the html call functions in external script files. How do I ensure that the external scripts are available for the embedded ones?

The downloaded JavaScript files (one or more) may be of large size. In such a context, how do I execute the JavaScript api present in HTML using v8? Code to run a JavaScript in v8 is below,

  // Create a string containing the JavaScript source code.
  v8::Local<v8::String> source =
      v8::String::NewFromUtf8(isolate, "'Hello' + ', World!'",
                              v8::NewStringType::kNormal)
          .ToLocalChecked();
  // Compile the source code.
  v8::Local<v8::Script> script =
      v8::Script::Compile(context, source).ToLocalChecked();
  // Run the script to get the result.
  v8::Local<v8::Value> result = script->Run(context).ToLocalChecked();

Assuming downloaded javascript is 200KB, how can I feed such a large buffer to v8::Script::Compile api. And when I have more than one file present, how can feed I them to v8 ?

Answer 1

How do I ensure that the external scripts are available for the embedded ones?

You load the external scripts first.

How do I execute the JavaScript API present in HTML using v8?

Do you mean the DOM? window , document and the like? The DOM is not part of ECMAScript, so V8 knows nothing about it; it is provided by the embedder (ie usually Chrome). In your own embedding you need to provide all those objects yourself, using V8's API. Needless to say, this is a huge amount of work. If what you're after is a way to render websites, then I recommend that you use some existing component/library for that, for example the Chromium Embedded Framework, or your favorite GUI toolkit's WebView (or whatever it is called).

Assuming downloaded JavaScript is 200KB, how can I feed such a large buffer to v8::Script::Compile API?

Just like you feed a small script to V8: put it into a v8::Local<v8::String> , then call v8::Script::Compile and v8::Script::Run .

And when I have more than one file present, how can feed I them to v8 ?

Call v8::Script::Compile and v8::Script::Run repeatedly, possibly using a loop. For an example, see V8's shell sample , specifically the function RunMain .

As I receive partial JavaScript in HTTP packets (chunks), can I pass the partial JavaScript to V8?

Yes, V8 has a script streaming interface. See the API documentation for v8::ScriptCompiler::ExternalSourceStream . For examples on how to use it, you can study the tests . Streaming may or may not be worth it for scripts as small as 200KB; it is definitely not required.