Some tips for smooth workflow and keeping developing in fast pace.

When the development is in front-end stage, developing it in GT environment is highly recommended.

Run the page in the GT Player (or the Coherent Player if you are using the Unreal Engine 4 Plugin) instead of Chrome or any other browser.

Run the GT Player from the package folder - .bat. Default location and name is set inside the .bat file:

SET _Url=coui://uiresources/sos/MainUI.html
SET _GTPlayerFolder=..\Samples\UI\bin\

With the Coherent Player (UE4 package), open Command Prompt where the CoherentPlayer.exe is located (package/CoherentPlayer/CoherentPlayer/Binaries/Win64). Next, run the player and set the coui root folder and page paths like so: CoherentPlayer.exe CoUIRoot="D:\package\CoUIGTTestFPS\Content\" -Page="coui://uiresources/MainUI.html". For full screen, press F11 after the scene loads or add -Fullscreen in the command line to start directly in full screen.

Use the debugger. While running the GT Player, open the Debugger and attach it to the page. To open the Debugger, click on the Tools button (top right corner) and click on Debugger.

For useful shortcuts click on the question mark icon on the Tools bar.

If running Coherent Player, in the command line add -InspectorPort=19999 and Make sure the inspector folder is inside package/CoherentPlayer/CoherentPlayer/Binaries/Win64 alongside CoherentPlayer.exe.

Do not enable "Show paint rectangles" and "Show composited layer borders" while profiling. This will add noise to the Recording.

More about the Debugger - UI Debugging and live editing

While developing the page, make sure vsync is set to 1 inside the .bat. Running without vsync puts high load to the CPU to show how fast the page can run in GT.
Loading external page inside the GT Player - inside the .bat file:

SET _Url=http://www.example.com/

This is the fastest way to check if something online is running as expected in GT.

Note: filter property works in GT only with prefix -webkit-filter.

Watch for Performance warnings while or after you close the GT Player. Open the CoherentUIGT.log inside the package folder \Samples\UI\bin\.