Pendulum Effect: When you Ritual Summon a monster: draw a card for each monster that was Tributed for that Ritual Summon. 
Monster Effect: When this card is Pendulum Summoned: You can add 1 Ritual Monster Card or 1 Ritual Spell Card from your Graveyard to your hand.

Can someone show me how to code pendulum monsters?

As far as I know you need to script it like this:

function cXXXXXXXX.initial_effect(c)
--pendulum summon
aux.AddPendulumProcedure(c)
--Activate
local e1=Effect.CreateEffect(c)
e1:SetType(EFFECT_TYPE_ACTIVATE)
e1:SetCode(EVENT_FREE_CHAIN)
c:RegisterEffect(e1)

That would be the pendulum activation.
Now, you would need to give it effects depending on the location:
LOCATION_SZONE for the pendulum effect
LOCATION_MZONE for the monster effect