So the Glock is sort of half double action?
Yes and no. The striker is held back just short of the opening in the slide for the firing pin to protrude before the trigger is pulled. The striker is pulled to the rear when the trigger is pulled back, then released as the trigger bar drops down releasing the striker to go forward and hit the primer of the cartridge, assuming it is loaded. The trigger also depresses the striker blocking pin to allow the striker to move all the way forward. Unless and until the trigger is pulled, the striker blocking pin blocks the forward travel of the striker in much the same way as the firing pin block does on a series 80 1911 style pistol.
The term double action presumes the existence of a hammer. In rather crude and not quite correct terminology it is "similar" to a DA in that the trigger action is necessary for the striker or hammer to be moved to full cock by the trigger in order to fire. Like a standard bolt action rifle, there just ain't no hammer in a Glock. Just the spring that powers the striker forward with enough energy to fire the primer.
And you say the trigger must be pulled for disassembly?
Yup, yes, si, da, yeah, oui, hai, ja. Does that make it clear?