F12 updates in Developer Channel

Internet Explorer Developer Channel features a number of cool updates to F12 developer tools, both large and small. Downloads are available for Windows 8.1 and Windows 7 SP1 customers running Internet Explorer 11. Please try out the features detailed below and provide feedback via Microsoft Connect.

What's new?

Let's look at what's new in the overall F12 tools user interface, then run down the updates by tool.

• Changes to the F12 user interface
• Console
• DOM Explorer
• Debugger
• Emulation
• UI Responsiveness
• Memory

Changes to the F12 user interface

• New icons and notifications

  The icons for the Memory and Profiler tools have changed.

  There are now indicators on the icon bar for errors in the Console, changes in Emulation settings, and for active profiling sessions in the Memory, Profiler, and UI Responsiveness tools. The image below shows the new icons with notifications on the Console and Memory tool icons, indicating there are two Console errors displaying and that a Memory profiling session is currently in progress.

  

• F6 superset navigation within tools

  Using F6 is like using the tab key to navigate around a tool, but it "tabs" through a selected set of the most commonly used elements in a tool pane, rather than through every selectable item. This is part of an overall cleaner system for using the keyboard to navigate within and between tools.

• Move back and forth between recently used tools using the keyboard

  Use CTRL + [ to move backwards in your tool navigation history, CTRL + ] to go forward, much like the back and forward arrows when you're browsing.

• Quick access to document mode

  Want to access the Document mode without switching tools? We added a new dropdown at the top that gives you access to the document mode from any tool.

  

Console changes

• Console.timeStamp()

  When called from the Console or within code, it outputs to the Console the number of milliseconds the current browser tab has been open. If called while running a profiling session with the UI Responsiveness tool, it creates a user mark on the session's timeline with a timestamp based on the time since the session started.

• CTRL+L clears the console of all messages

• Accurate autocomplete

  Console's autocomplete no longer includes indexer properties, making for a cleaner and more accurate selection of autocomplete suggestions.

  $, $$, $x, $0-$5, and $_ have been added to the Console autocomplete list for the convenience for those who use them and to make the Console's behavior more consistent with other browsers.

• Stale message indicator

  If you have chosen to turn off the Clear on navigate option, older console messages have their icons greyed out to help distinguish between messages for the active page and messages from prior pages in your history.

  

DOM Explorer changes

• Change bars in Computed pane

  The change bars (different colors for changed properties, added properties, and deleted properties) users have been enjoying the Styles pane, now appear in the Computed styles pane.

  

Debugger changes

• Sourcemaps designate

  Right-click on a document's tab in the Debugger and you can specify a source map. This makes it possible to use source maps with shipped code that has had the source map comment removed.

  

• Autocomplete in watches

  Now, when adding a watch, you get autocomplete options suggested.

  

• Return value inspection

  When breaking on a function with a return value, step into the function until you've stepped to the closing curly bracket. The return value will be displayed in the Locals portion of the Watches pane. Step again and the value will be returned to the code that called for it.

  For a quick demonstration, try this code in the Console:

  function showval() { var x = 0; x++; debugger; return x; } showval();

  It will call the function, break on debugger, and you can step into it to see the return value.

• Multi-select for breakpoints

  CTRL + CLICK, SHIFT + CLICK, and CTRL + A work to select multiple breakpoints in the Breakpoints pane.

• Continue and ignore breaks

  Press F5 to continue to the next break. Hold F5 to continue past multiple breaks until you release F5.

• Event breakpoints and tracepoints

  These work much like the breakpoints and tracepoints already present in F12 tools, but instead of being triggered when a specific block of code is executed, they are triggered when a specific event fires. Each has an optional conditional filter to help you narrow down their scope to the specific instance of an event that you want to inspect. They can be added using the Add event tracepoint and Add event breakpoint icons highlighted in the image below.

  

UI Responsiveness tool changes

• Import/export performance sessions

  You shouldn't have to reproduce your test case every time you want to analyze data it produces or share that data with a colleague. The import (folder) and export (disk) icons on the UI Responsiveness tool's icon bar let you save your memory snapshots to a file that can be imported later.

• Image preview

  If you've seen an HTTP request for an image and wondered which image it was, the image is now previewed in the event details.

  

• Filtering events

  The Filter events button is small but mighty. Hidden behind that button is a menu that lets you filter events in multiple ways and each way has a significant impact.

  • Event name filter

    Filter for any event name containing a match for the filter text.

  • UI activity filter

    Using the checkboxes, you can exclude larger categories of events to make it easier to focus on the area you're investigating. For example, if you're just interested in network activity, you can filter out all the noise of the UI and garbage collection.

  • Time threshold filter

    This feature filters out top-level events less than 1ms in duration. In many scenarios, this dramatically simplifies the waterfall view and helps you focus on more impactful events.

  

• HTML5 scripting events

  If you use media query listeners or MutationObservers, you can now identify their respective costs when running a performance profiling session.

  

• Frame grouping

  The button between the Sort by dropdown and the Filter events menu toggles Frame grouping. This groups top-level events into their corresponding unit of work (or "frame") during periods of time where animations/visual updates were occurring. The frames are treated like other events, so they can be sorted and filtered, and they provide an Inclusive time summary.

  

• User measures

  If you use the performance.mark() API to add triangles to the timeline, indicating where specific events happened, the performance.measure() API extends the usefulness of performance marks. Use the performance.measure() to create a User measure event encompassing the time between two performance.mark() events, right click the event, and use the Filter to event option to select just the events between the two marks.

  

• Colorization for DOM

  This feature adds colorization to DOM elements, string literals and number literals. Besides making the content within the different F12 tools look and behave more alike, it adds a little more visual interest to the UI Responsiveness tool.

• Selection summary

  When you select a portion of the timeline, the event details pane will show a summary of the selection. Hover over different segments of the circular chart for a tooltip with the segment's event category.

  

• Support for console.timeStamp()

  Using the console.timeStamp() method in your code or in the console during a profiling session creates a user mark on the timeline with the time since the profiling session began.

Memory tool changes

• Dominator folding

  Dominator folding helps simplify the contents of a snapshot by removing objects from the top-level views that are logically components of another object (e.g. a <BR> within a <DIV>, a Scope held on to by a Function) and tend to be extra details that don’t improve your insight into the data, but could waste your time.

  For example, the image below shows before and after views, demonstrating how dominator folding improves the "story" the tool is telling. The folded view shows 30 HTML <DIV> elements, which account for 15.64 MB of memory, and are holding on to detached DOM nodes. In many cases, it isn’t important to know the composition of an object, so much as simply knowing that it is too large, or that it is leaking (especially when using third-party libraries).

  

• Colorization of DOM, String & Number literals

  This feature adds colorization to DOM elements, string literals, and number literals. Besides making the content within the different F12 tools look and behave more alike, it makes memory analysis a little more visually interesting.

• Roots cycle filtering

  Want to be able to investigate the composition of an object without getting unknowingly lost in a circular reference path? This feature detects child references which are circular and “trims” them, so that you don’t get confused by traversing them into infinity. Additionally, it annotates these references so that it’s clear when a reference has in fact been "trimmed."

• Import/export session

  You shouldn't have to reproduce your test case every time you want to analyze data it produces or share that data with a colleague. The import (folder) and export (disk) icons on the Memory tool's icon bar let you save your memory snapshots to a file that can be imported later.

  

Emulation tool changes

• Settings persistence and reset

  A Persist Emulation settings icon is added to the Emulation tool. This will maintain your current emulation settings until specifically disabled, allowing you to work, close the browser, and come back with your emulation settings intact. To its right is a Reset Emulation settings icon, which quickly resets the tool back to default values.

  

Related topics

Download Internet Explorer Developer Channel for Windows 8.1

Download Internet Explorer Developer Channel for Windows 7 SP1