Extending Craft CMS CP with Hooks and Events

When I’m work­ing in Craft CMS, I tend to have a lot of open tabs, and some­times tabs from dif­fer­ent envi­ron­ments of the same project. For that rea­son, it’s nice to be able to clear­ly see which envi­ron­ment I’m cur­rent­ly in, so I don’t test or update the incor­rect environment.

To solve this, we’ll build a cus­tom mod­ule that dis­plays the envi­ron­ment in the title tag/​tab name, and as a ban­ner at the top of the con­trol pan­el. Along the way, we will also learn about how to cus­tomize the con­trol pan­el with tem­plate hooks and events.

You might remem­ber that in a pre­vi­ous video, we talked about how to add cus­tom tem­plate hooks in Craft CMS to make it sim­pler to inject cus­tom code into your front-end templates. 

Craft CMS also has tem­plate hooks for inject­ing your own code into the con­trol pan­el templates.

How­ev­er, things have changed over the last cou­ple of major ver­sions of Craft CMS, and the empha­sis is now on using events instead of tem­plate hooks for cus­tomiz­ing Craft CMS con­trol panel.

Let’s take a look at this for some back­ground infor­ma­tion before we jump into how to cus­tomize the con­trol pan­el with our own code.

1. CP Tem­plate hook removal between Craft 3 and 4: https://​craftcms​.com/​d​o​c​s​/​4​.​x​/​e​x​t​e​n​d​/​u​p​d​a​t​i​n​g​-​p​l​u​g​i​n​s​.​h​t​m​l​#​t​e​m​p​l​a​t​e​-​hooks
2. CP tem­plate hooks in Craft 4: https://​craftcms​.com/​d​o​c​s​/​4​.​x​/​e​x​t​e​n​d​/​t​e​m​p​l​a​t​e​-​h​o​o​k​s​.html
3. CP tem­plate hooks in Craft 5: https://​craftcms​.com/​d​o​c​s​/​5​.​x​/​e​x​t​e​n​d​/​t​e​m​p​l​a​t​e​-​h​o​o​k​s​.html

Even though there aren’t that many CP hooks left to use, we’ll use one to manip­u­late the title tag and then move to Events in Craft CMS to add addi­tion­al changes to the Con­trol Panel.