Talk:Command Block

"Conditional" Command Blocks
All command blocks use this feature, not just Chain command blocks. Furthermore, all command blocks check behind themselves, including Chain blocks, rather than in sequence ("previous"). In this image, #4 is set to conditional and requires #1 to be successful in output, not #3. It needs #3 in order to connect to the chain of commands.

Impulse blocks behave as expected (image); the command block on the right is conditional but cannot run its command unless the one "behind" it (opposite of its facing) is successful.

Repeating blocks are the same as Impulse blocks, except they will not constantly send a signal if the block behind them was unsuccessful.

And while a conditional command block does not run its command if the block behind it fails, it will still push a signal through chain blocks. That means in this image, if the Repeating block is conditional and fails, all the chain blocks are activated once. Since it's a Repeating block, it will not send a signal after that point until a block behind it is successful. It's the same for Impulse blocks, minus the fact that they can't clock.

Not in a position to do major edits though, so just relaying info. Skylinerw (talk) 20:08, 20 August 2015 (UTC)


 * I think I see what you're saying. I'll make a stab at correcting the article. &mdash;munin &middot; Grid_Book_and_Quill.png Grid_Stone_Pickaxe.png &middot; 20:20, 20 August 2015 (UTC)

DEFAULT Setting for Chain blocks
Chain command blocks all defaults to "always active", meaning they will activate depends on what chained to it, regardless the redstone. 221.221.224.140

Animated grid image
As with sea lanterns and prismarine, it would be nice if we could have an animated version of the grid image. —Fenhl 12:08, 12 September 2015 (UTC)

"Success" difference in Chain vs. Conditional not documented on this page?
There appears to be a small discrepancy in the page describing how the new command blocks work Two excerpts from the wiki: And the statement that:
 * "Conditional": The command block should only execute its command if the command block behind it executed successfully
 * "Chain" blocks are green. These execute only when the command block pointing to it executes successfully.
 * This differs from the Conditional option in that it detects what is pointing to it, instead of simply behind it. The command blocks pointing to it also need not be chain blocks themselves to trigger the chain.

This seems to imply that both options use the same type of 'success' and that it only differs between which block is checked, however a simple test shows this is not the case:

Setup: A button, a line of redstone weakly powering a command block, pointing into to another command block whose "back" correctly faces the previous. ( Images here ) ** CB1 is a regular impulse containing a 'testfor playernamehere' command CB2 contains 'say CB2 fired'

Tests:
 * 1) CB2 is a chain command block,  the player is NOT on the server, the button is pressed. - Results: 'CB2 fired' displayed
 * 2) CB2 is a conditional impulse command block,  the player is NOT on the server, the button is pressed. - Results: Nothing is displayed, CB2 is not activated.
 * 3) CB2 is a conditional chain command block,  the player is NOT on the server, the button is pressed. - Results: Nothing is displayed, CB2 is not activated.
 * 4) CB2 is a conditional repeat command block*,  the player is NOT on the server, the button is pressed. - Results: Nothing is displayed, CB2 is not activated.
 * 5) CB2 is a chain command block,  the player IS on the server, the button is pressed. - Results: 'CB2 fired' displayed
 * 6) CB2 is a conditional impulse command block,  the player IS on the server, the button is pressed. - Results: 'CB2 fired' displayed
 * 7) CB2 is a conditional chain command block,  the player IS on the server, the button is pressed. - Results: 'CB2 fired' displayed
 * 8) CB2 is a conditional repeat command block*,  the player IS on the server, the button is pressed. - Results: 'CB2 fired' is displayed repeatedly until the button unpowers CB1

(1.9/vanilla) (* not shown in image, ** Alternatively, you can power a block next to CB1 for the chain-block tests.)

Because of the alignment, both the conditional and chain draw their 'success' check from the same preceding block, which means they determine success differently if the wiki's description is true. However, this information is not present on the wiki page.

In particular, it appears the Chain command block executes whenever the previous command block is executed, regardless of the command's success value,

and the Conditional block executes when the previous command block is executed AND the command has succeeded.

-- 72.214.181.74 02:57, 12 March 2016 (UTC)


 * Alternatively, for the chain-block tests only, you can power a solid block next to CB1 with the same results. -- 72.214.181.74 03:19, 12 March 2016 (UTC)


 * I think the solution here would be to reword one of the "successfully"s as they obviously don't mean the same thing - one is that the command actually ran (not necessarily with a successcount) - the other is that the command ran and had a successcount -- 72.214.181.74 03:17, 12 March 2016 (UTC)


 * Fixed the page for clarification about chain execution to not include "successfully", however be aware that you have run into a bug on how a conditional Impulse/Repeating block can't execute until the next tick. See MC-99343 for more information. Skylinerw (talk) 14:36, 12 March 2016 (UTC)