What's New In DevTools (Chrome 71)
New features and major changes coming to Chrome DevTools in Chrome 71 include:
- Hover over a Live Expression to highlight a DOM node
- Store DOM nodes as global variables
- Initiator and priority information now in HAR imports and exports
- Access the Command Menu from the Main Menu
- Picture-in-Picture breakpoints
- (Bonus Tip) Run monitorEvents() in the Console to watch an element's events fire
Read on, or watch the video version of this page:
Hover over a Live Expression to highlight a DOM node #
When a Live Expression evaluates to a DOM node, hover over the Live Expression result to highlight that node in the viewport.
Figure 1. Hovering over a Live Expression result to highlight the node in the viewport
Store DOM nodes as global variables #
To store a DOM node as a global variable, run an expression in the Console that evaluates to a node, right-click the result, and then select Store as global variable.
Figure 2. Store as global variable in the Console
Or, right-click the node in the DOM Tree and select Store as global variable.
Figure 3. Store as global variable in the DOM Tree
Initiator and priority information now in HAR imports and exports #
If you'd like to diagnose network logs with colleagues, you can export the network requests to a HAR file.
Figure 8. Exporting network requests to a HAR file
To import the file back into the Network panel, just drag and drop it.
When you export a HAR file, DevTools now includes initiator and priority information in the HAR file. When you import HAR files back into DevTools, the Initiator and Priority columns are now populated.
_initiator field provides more context around what caused the resource to be requested. This maps to the Initiator column in the Requests table.
Figure 9. The initiator column
You can also hold Shift and hover over a request to view its initiator and dependencies.
Figure 10. Viewing initiators and dependencies
_priority field states what priority level the browser assigned to the resource. This maps to the Priority column in the Requests table, which is hidden by default.
Figure 11. The Priority column
Right-click the header of the Requests table and select Priority to show the Priority column.
Figure 12. How to show the Priority column
_priority fields begin with underscores because the HAR spec states that custom fields must begin with underscores.
Access the Command Menu from the Main Menu #
Use the Command Menu for a fast way to access DevTools panels, tabs, and features.
Figure 13. The Command Menu
You can now open the Command Menu from the Main Menu. Click the Main Menu button and select Run command.
Figure 14. Opening the Command Menu from the Main Menu
Picture-in-Picture breakpoints #
Picture-in-Picture is a new experimental API that enables a page to create a floating video window over the desktop.
resize checkboxes in the Event Listener Breakpoints pane to pause whenever one of these picture-in-picture events fires. DevTools pauses on the first line of the handler.
Figure 16. Picture-in-Picture events in the Event Listener Breakpoints pane
(Bonus Tip) Run monitorEvents() in the Console to watch an element's events fire #
Note: This section covers a lesser-known feature that has been in DevTools for a long time.
Suppose you want to add a red border around a button after focusing it and pressing
D, but you don't know what events to add listeners to. Use
monitorEvents() to log all of the element's events to the Console.
Get a reference to the node.
Figure 17. Using Store as global variable to get a reference to the node
Pass the node as the first argument to
Figure 18. Passing the node to
Interact with the node. DevTools logs all of the node's events to the Console.
Figure 19. The node's events in the Console
unmonitorEvents() to stop logging events to the Console.
Pass an array as the second argument to
monitorEvents() if you only want to monitor certain events or types of events:
monitorEvents(temp1, ['mouse', 'focus']);
mouse type tells DevTools to log all mouse-related events, such as
click. Other supported types are
Check out Command Line Reference for other handy functions that you can call from the Console.