Piston API gives blocks a way to have position & world sensitive interactions with pistons! Mainly the block's pushability, and its stickiness.

IPushableBehavior:

• This interface adds one method getPushReaction (which takes in the block source & piston info, and returns the EnumPushReaction). Blocks should implement this if they have advanced push reaction logic. This interface overrides vanilla's getPushReaction(IBlockState) method, blocks that don't implement the interface fallback on vanilla's method. For modpack devs: Each block's push reaction can be overriden by calling PushReactionHanlder.overridePushReaction through Groovyscript during postInit (mod devs should not do this!)
• Grovvyscript examples:

import static git.jbredwards.piston_api.mod.asm.PushReactionHandler.overridePushReaction
import net.minecraft.block.material.EnumPushReaction

//makes dirt be destroyed by pistons when pushed (like grass or leaves)
overridePushReaction(block('minecraft:dirt'), EnumPushReaction.DESTROY)

//makes orange wool not pushable by pistons, while leaving the rest pushable
def orangeWool = blockstate('minecraft:wool', 1)
overridePushReaction(block('minecraft:wool'), {source, pistonInfo -> orangeWool == source.getBlockState() ? EnumPushReaction.BLOCK : EnumPushReaction.NORMAL})

IStickyBehavior:

• This interface adds two methods: getStickReaction (which takes in the block source, the neighbor block to test, and piston info, and returns the EnumStickReaction), and hasStickySide (which takes in the block source & piston info, and returns whether the block has any potentially sticky sides). Blocks should implement this if they have advanced stickiness logic. This interface overrides forge's isStickyBlock(IBlockState) method, blocks that don't implement the interface fallback on forge's method. For modpack devs: Each block's stick result can be overriden by calling StickReactionHanlder.overrideStickReaction through Groovyscript during postInit (mod devs should not do this!)
• Groovyscript examples:

import static git.jbredwards.piston_api.mod.asm.StickReactionHandler.overrideStickReaction
import git.jbredwards.piston_api.api.piston.EnumStickReaction

//makes slime blocks not sticky
overrideStickReaction(block('minecraft:slime'), EnumStickReaction.PASS)

//makes crafting tables sticky
overrideStickReaction(block('minecraft:crafting_table'), EnumStickReaction.STICK)

//makes bookshelves never stick to anything
overrideStickReaction(block('minecraft:bookshelf'), EnumStickReaction.NEVER)

//makes stained glass sticky, but only to the same color
overrideStickReaction(block('minecraft:stained_glass'), {source, other, pistonInfo -> source.getBlockState() == other.getBlockState() ? EnumStickReaction.STICK : EnumStickReaction.PASS})

//a more complicated example, makes the open part of logs sticky
import static git.jbredwards.piston_api.api.block.IStickyBehavior.getConnectingSide
import net.minecraft.block.BlockLog
overrideStickReaction([block('minecraft:log'), block('minecraft:log2')], {source, other, pistonInfo ->
    def connectingAxis = BlockLog.EnumAxis.fromFacingAxis(getConnectingSide(source, other).getAxis())
    def logAxis = source.getBlockState().getValue(BlockLog.LOG_AXIS)

    connectingAxis == logAxis ? EnumStickReaction.STICK : EnumStickReaction.PASS
})