Accessing Index From Within Then()

Question

I am using OBS Websockets to connect to multiple OBS instances. As a result, I have a foreach() loop to loop over each instance, and call a connect function. This should connect to OBS and populate a dropdown list for each instance, showing available scenes.

My problem is I need to know which sheet I am on (index is part of the for loop, but because the function is async by the time it completes, the index has moved on:

for(sheetIndex = 0; sheetIndex  < 8; sheetIndex++)
{
    connect(sheetIndex);
}

function connect(sheetIndex)
{
    const obs = new OBSWebSocket();
        
    obs.connect({ address: address })
    .then(() => {
        console.log(`${name} connected on ${address}`);
          
        // get a list of the scenes
        await obs.send("GetSceneList").then((data) => {

        console.log("New sheet index: " + sheetIndex);

        data.scenes.forEach((scene) => {

              var sceneListSelect = document.getElementById("SceneListSheet" + sheetIndex);
              var opt = document.createElement("option");
              opt.innerHTML = scene.name;
              sceneListSelect.appendChild(opt);
        }
    });
}

The value of sheetIndex is unpredictable within the "then", as the for loop has moved on to the next iteration before the call to GetSceneList completes. How can I pass in the value of sheetIndex in to the "then" function so its value is frozen at the time of calling?

Answer 1

You need to declare the dependency. If you're using maven add the following to pom.xml

<!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
<dependencies>
  <dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-api</artifactId>
    <version>2.17.0</version>
  </dependency>
  <dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.17.0</version>
  </dependency>
</dependencies>

Or if you're using gradle, add the following to build.gradle:

dependencies {
  compile group: 'org.apache.logging.log4j', name: 'log4j-api', version: '2.17.0'
  compile group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.17.0'
}