The code checks if client and $ are defined, and if so, executes a block of code. It also contains functions to execute an asynchronous method and handle client window handles, including sending results or errors through the $ object.

Cell 15

if(typeof client !== 'undefined' && typeof $ !== 'undefined') {
    $.async();
    client.windowHandles()
        .then(r => $.sendResult(r))
        .catch(e => $.sendError(e));
}

// Check if client and $ are defined
if (typeof globalThis.client!== 'undefined' && typeof globalThis.$!== 'undefined') {
    // Initialize async operation
    $.async();

    try {
        // Get window handles
        const windowHandles = await client.windowHandles();
        
        // Send result
        $.sendResult(windowHandles);
    } catch (error) {
        // Send error if any
        $.sendError(error);
    }
}

Code Breakdown

Conditional Statement

if (typeof client!== 'undefined' && typeof $!== 'undefined') {
  // code to be executed if condition is true
}

• Checks if client and $ are defined. If both are defined, the code inside the block is executed.

Execution of Async Function

$.async();

• Calls the async() method on the $ object.

Client Window Handles

client.windowHandles()
 .then(r => $.sendResult(r))
 .catch(e => $.sendError(e));

• Calls the windowHandles() method on the client object, which returns a promise.
• .then() block: If the promise is resolved, calls sendResult() on the $ object with the result r.
• .catch() block: If the promise is rejected, calls sendError() on the $ object with the error e.