Call existing JS function from RenderProcess

[SteveMcFarlin]

Hello All,

I have a project that is mimicking a small subset of the Puppeteer API. I am looking for a way to call an existing JS function within a window/frame. Essentialy I am trying to duplicate this https://pptr.dev/api/puppeteer.page.evaluate. I see there is the Eval function on the CefV8Context, but that appears to simply evaluate JS in the string parameter. Please correct me if I am wrong here. Essentially I would like to do the following.

Given this JS function in a frame/page

Code: Select all

function someFunc({
   ...
}) {...}


Call the function from the render process

Code: Select all

context->Eval("someFunc", args, ...);


As an alternative I do see I could modify the page to register the function with the render process per the docs: https://bitbucket.org/chromiumembedded/cef/wiki/JavaScriptIntegration.md#markdown-header-executing-functions.

I am wondering if what I am trying to do is possible with CEF. Thanks for any Help.

[magreenblatt]

If you don’t need a return value you can just call ExecuteJavaScript. Otherwise, you’ll need to use something like MessageRouter to send the result back to the main/browser process. CefSharp has a EvaluateScriptAsync method that you can use as a model (implemented using the technologies mentioned above).

[magreenblatt]

I've also filed https://github.com/chromiumembedded/cef/issues/3631 (and result callback to ExecuteJavaScript)

[SteveMcFarlin]

Thanks. That works out good enough for my purposes. Luckily I do not need any return values currently I'll keep an eye on your issue.

[KatrinaS]

I've also filed https://github.com/chromiumembedded/cef/issues/3631 (and result callback to ExecuteJavaScript)

As you note it's unnecessary given the mechanisms already in place but if a user is only interested in a quick std::string / String etc value then it's still a handy addition to the toolbox

Oh,, it would be handy if it could return an Array too