(1.11.2) can you give the player a potions effect while standing on a modded block

[J_Dev]

I added a new block to Minecraft and I was wondering if I could possibly give the player an effect while standing on said block. If it is possible, how would i go about setting it up? 

[Choonster]

Block#onEntityWalk is called when an entity (that can trigger walking) walks on top of a block. If a block has a collision bounding box smaller than a full block, Block#onEntityCollidedWithBlock is called when an entity collides with the block.

 

You can override one of these two methods to check if the entity is an instance of EntityLivingBase and then use EntityLivingBase#addPotionEffect to add a potion effect to the entity.

[Draco18s]

I will note, however, that onEntityWalk is not 100% reliable.

[jeffryfisher]

How you have your block detect an entity depends on what area of effect you want. Do you want the effect if a player walks on top of a carpet laid on top of your block? If so, then you need to look beyond collision.

 

If your block is going to be rare (not spawning by the thousands or millions in the world), then you could use a tile entity to do a short-range living entity search and apply the status effect to those you deem worthy. Alternatively, you could add randomness (and avoid using a TE) by setting your block to tick randomly and doing your short-range search then.

 

You might find other ideas by looking at vanilla coding for  beacons.

[J_Dev]

Thank you everyone! with your help, I was able to figure out what to do.