get Har Log as java object from selenium

[joshhe]

Hi,

I am wondering if there is way to get the har log as a string or object using selenium in java? Currently I would have to read from the saved har file and read that in as a string. I know we can trigger the har export through java script, but I don't know how to get it in the java code...

Something like this?
driver.get("https://google.com");
if(driver instanceof JavascriptExecutor) {
((JavascriptExecutor) driver).executeScript(
" var options = { token: "mySpecialValue", getData: true, title: "Title for the HAR log", jsonp: false,};" +
"HAR.triggerExport(options).then(result => { var har = JSON.parse(result.data); console.log("HAR log: ", har.log);}, err => { console.error(err);});");
}

then, how do I get it in java code...
Thanks!

[janodvarko]

I don't have much experience with Java and Selenium, but could you just store the HAR log (as a text) inside an element on the page:

  var options = {
    token: "test",
    getData: true,
  };

  HAR.triggerExport(options).then(result => {
    var harNode = document.getElementById("content");
    harNode.textContent = result.data;
  });

...and then do something like as follows in Java:

WebElement harNode = driver.findElement(By.id("content"));
String harLog = harNode.getText();

Honza

[joshhe]

That's awesome! Thanks for the tip. It works!

[janodvarko]

Excellent, out of curiosity, can you paste the full example here?
Honza

[joshhe]

Here is code I have, it uses sessionStorage to store the har.
String harLog = null;
if(driver instanceof JavascriptExecutor) {
((JavascriptExecutor) driver).executeScript(
" console.log("here"); var options = { token: "test", getData: true, jsonp: false}; console.log("here3"); " +
"HAR.triggerExport(options).then(result => { console.log(result.data); sessionStorage.har = result.data; });");
}

for(int i = 0; i < 20 && harLog == null; i++) {
  if (driver instanceof JavascriptExecutor) {
    harLog = (String) ((JavascriptExecutor) driver).executeScript(
            "return sessionStorage.har;");
  }
  Thread.sleep(1000);
}

This works for most of the websites I tested. But I ran into two edge cases.

1. http://www.asdfalsdfjkl.com
   When the host name cannot be resolved, no har is generated. Even though I have the "devtools.netmonitor.har.forceExport" set to true. An exception is thrown "HAR is not defined" when I try to get it through the API. However, when I have the ""devtools.netmonitor.har.enableAutoExportToFile" set to true, there is actually a .har file been exported. But there is not error indicating that the hostname cannot be resolved in the har.

2. http://cnet.com
   This site is loaded twice on a single driver.get(url) call, at the end, when I try to get the har string, it's always null through the API call. However, when I have the "devtools.netmonitor.har.enableAutoExportToFile" set to true, I actually see two .har files been exported. I don't know why it doesn't work when I call it using the API.

Do you know how to resolve those two edge cases when I try to get har through the API? autoExportToFile works for all cases, but I don't really want to read har file in as string if I don't have to.

Thanks!

[janodvarko]

Both these cases look like a bug. I'll investigate it

Honza

[tobli]

@chemicwepn - it should work if you use executeAsyncScript. I'm using a similar setup, but from node.js.
My async script is:

const script = `
var callback = arguments[arguments.length - 1];
function triggerExport() {
  HAR.triggerExport({'token':'test', 'getData':true})
  .then((result) => callback(result.data))
  .catch((e) => callback(e));
  };
if (typeof HAR === 'undefined') {
  addEventListener('har-api-ready', triggerExport, false);
} else {
  triggerExport();
}`;
return driver.executeAsyncScript(script);

I guess in you case replace the callback(result.data) with

{
  sessionStorage.har = result.data;
  callback();
}

to indicate that the async process of generating and storing the har is done.

[batmantest7]

Hi Team,

Is the issue for the case 2] solved?
2) http://cnet.com
This site is loaded twice on a single driver.get(url) call, at the end, when I try to get the har string, it's always null through the API call. However, when I have the "devtools.netmonitor.har.enableAutoExportToFile" set to true, I actually see two .har files been exported. I don't know why it doesn't work when I call it using the API.

My test case is:
1] Get url1
2] Do something
3] Get url1
4] Do something else

Result generated:

Only the step 3] and step 4] har logs are captured in the .har file

The step 1] and step 2] har logs are not captured.

Is there any tracking bug for this?

When I set "devtools.netmonitor.har.enableAutoExportToFile" set to true, logs are generated for all steps.

Thanks.