Custom Segments

Thanks to Inspector you are able to put everything you want in the transactions timeline getting a real-time feedback about the execution of a code block inside your application.

By default Inspector will report many different tasks based on the application's dependencies, but you are free to "wrap" some parts of your code that you consider relevant to create a more complete picture of what statements are executed during an execution cycle and its performance.

Short form

Just a few lines of code are needed:

inspector.addSegment(() => {
    
    // Your statements here...
    
}, 'type', 'label')

This will produce a new segment in the timeline:

As showed in the example above a new segment is built with three input parameters:

Think about how database queries is reported. That's one master category like mysql but each query has its own custom label that simply is an extract of the sql code executed for a better timeline consultation.

• mysql: master type

• select * from table...: label

In this way you can mark toghether the statements related to a specific task using something like csv-export as type parameter and use the filename as label for each statement of this type.

Get return

What you return from your callback will be returned back by addSegment() method.

/**
 * "result " will contains the string "Hello".
 * 
 * Note the use of "await".
 */
let result = await inspector.addSegment(() => {
    
    // Your statements here...
    
    return 'Hello'
    
}, 'csv-export', csvFileName)

Working with Promise

// Use await
await inspector.addSegment(...)
​
// Use then/catch
inspector.addSegment(...)
    .then()
    .catch()

Add contextual informations

If you need to report some contextual information, the new segment will be injected as callback parameter:

/**
 * "result " will contains the string "Hello"
 */
let result = await inspector.addSegment(segment => {
    
    // Your statements here...
    
    // Attach interesting data
    segment.addContext('payload', {
        foo: 'bar'
    })
    
    // return a result if needed
    return 'Hello'
    
}, 'csv-export', csvFileName)

Some ideas to use custom segments

Here are some scenarios where new segments can help you to anticipate bugs and bottlenecks:

• Http call to external services (webhooks, integration, etc.)

• Functions that deal with files (pdf, excel, images)

• Data manipulation processes (import/export, data aggregation, etc.)