I'm trying to make a map but I'm stuck on a command When a player crafts an item I want to let it only be placed on a block, like when a player crafts a crafting table, the command block will make so it's only placeable on gravel. I seen it in other maps. How do I do it? Also I want to make it so certain tools and break some blocks If anyone knows please tell me. P.S. not the /give command
I want to detect when someone is building a lever, then replace it with another lever that has the canplaceon tag so it can be placed on a redstone_lamp  How can I clear the crafting item and replace it with one that has a canplaceon tag?
Time Dilation When In Orbit Mapping of zero vector under a linear transformation Let $T$ be a linear transformation from a vector space $V$ to $W$ that are defined over a field $\mathbb F$.   Now, $T(\mathbf0)=\mathbf0$.   Which implies the zero vector in $V$ can't move or be transformed to a new vector in $W$. Why is it so?   Does it also have a geometrical significance? Getting the starting shortcut in c# Transparent textured planes produce black artifacts How to use "fit" to frame the nodes and labels Science Fiction novel or novels about starship that becomes a god, colonizes hostile planet Plot Summary/Details  The sharpest memory I have of this one is that it was unusually dense reading. Much more difficult going than most of the sci-fi stuff I'd read by that time (I was 10 or 11, I think).  What I remember in terms of plot is that there is a starship, sent either to explore, or colonize, a distant star system.  I don't remember the names of any of the characters, but I think maybe they discover they are clones?  In any case, something happens to the computer system that the onboard AI becomes sentient and develops a measure of omniscience and omnipotence.  It effectively becomes a god of sorts.  The next part I can remember, and I'm not sure this is the same book or not, is that the ship has forcibly settled the crew on a hostile planet.  All sorts of nasty indigenous life forms live here, and guards are post on the wall outside the settlement to destroy them as they try to enter.  I remember there is a female character standing watch, and she goes over the bestiary in her mind.  One particularly nasty creature paralyzes you, and then burrows up your spine into your brain (or something like that) if it gets a hold of you.  That's all I can recall.  Not a lot of detail, unfortunately, but I'm having a tough time remembering much about this one.  I never finished the book(s), as they were mostly "over my head" at that age. Design problem - Implement an approval process on case, which sends email to approver showing some additional info, which should not be visible to case owner/agent (who clicked on "Submit for approval" button).  Possible solution - All that additional info will not be stored on Case (otherwise agent will also be able to see it). I am creating a child object to case, where all that additional info be stored. We can make sure agent does not have access to that child object (lets call it ChildObj).   In the email template used, we can include info about that child object. From what i understand, standard email templates dont allow cross object reference. We probably need to use visualforce email templates.  Questions -  1) Can anyone see/point out any issues with that design? 2) I am very new to salesforce. Can anyone give me any example of how i will access child record's field? I mean there won't be any lookup or anything to child object, right? How do i access a field on the child object? Any clue would be helpful Much as I loathe Microsquish's Word, it does allow you to insert into a header or footer the automated text "Page X of Y."   When using InDesign, it's easy to set up the "Page X" part on a master page. But is there any placeholder character for the Y? That is, it will count the number of pages in the document, either in an absolute or a relative-to-the-section fashion? Every now and again I narrowly miss sending out something with a footer which reads "Page 4 of 3," and I would love to know if there's some way around that. Currently, once an edit by a user without full edit privilege is suggested, it can be either approved or rejected.  There is a known edge case that cause suggested edits to get auto rejected: (aka edit conflict)   User with full edit privilege click "edit" and start typing. Let's name this user Joe. Since the user from previous step did not yet send the edit, users without full edit privilege can still click the "edit" as well, oblivious to the fact someone else is editing the same post in those very seconds. Such user click "edit" too and start typing. Let's name this user Kenny. Kenny is faster than Joe: he send his edit first, creating new suggested edit. Joe is still typing. Joe finally done typing. He send his edit to its merry way oblivious to the consequences. As result of the full edit made by Joe, Kenny's suggested edit is kicked away and rejected. Boom.   This is all known and reported many times.  where the user got it hard with at least two auto rejections in short period of time. Some concrete examples: , , .  For edge case, it became pretty thick edge. This is not just minor hassle: enough rejections, and the user is banned from suggesting for a whole week: and remember we're talking here about good edits made by good users. The above used to count for the ban, but . Thanks Gilles for requesting such a change!   I know it was already suggested to lock edits and similar solutions, but I suggest whole different approach: instead of auto rejecting the suggested edit, dismiss it, i.e. cancel it like it never existed same way a bounty can be revoked by moderator.  In the edit suggestion page it will show "Dismissed" instead of Approved or Rejected maybe with a tooltip explaining what caused this. This will soften the blow from those edge cases, taking the edge out of them. :) Simulating Key Press C# Is it possible to use the laptop's audio via headphone jack and Bluetooth speakers at the same time? Lolo Joe wants earphone jack to plug and use big speakers but at the same time he wants to partner the music coming out the earphone jack and his Bluetooth system and speakers. Is it even possible to use the earplug connection and the Bluetooth system and devices at the same time? Can wizards create their own spells? In the Harry Potter series, are wizards capable of creating their own spells, or are they limited to the spells that they're taught/learn?  I seem to remember something about Snape creating sectumsempra, but I'm not sure if that really is the case. Why doesn't the Moon fall onto the Earth? Why doesn't the Moon fall onto the Earth? For that matter, why doesn't anything rotating a larger body ever fall onto the larger body? Are {/bin, /lib, /sbin} symlinks into /usr in Ubuntu? I do not have access to an Ubuntu system or chroot. I was hoping if someone could tell me if the  is accurate in saying:     For Quantal, merged /usr should be supported. On new systems installer should create {/bin, /lib, /sbin} symlinks into /usr. Materials for learning TikZ I have got the Client Cross Frame Scripting Attack alert in the recent CheckMarx scanner. However, it points to an auto generated ID.   I've seen the following links however, the I'm not sure about relavancy of the soluions given i.e.,          Regarding my visualforce component, I'm doing just one DML operation on a custom setting from a callout response. Also, I'm not passing any attribute to the component.   To give a background of the component, its just a list view of records from a different system retrieved through a callout on load via JavaScript.  Let me know if in case anything else is needed.   Thanks in Advance! Peace! What is the remainder of $\,3^{3^{3^{\:\!\phantom{}^{.^{.^.}}}}}\!\!\!$ divided by $46$?  The level of powers is $2020$.  First there is no parenthesis so it means 3 power of 3 which is also power 3 and so on 2020 times  Second I think that we can use Fermat's Little Theorem but I don't know how, and maybe there is a better way. Find & Delete duplicated files on multiple harddisks at once I have a 32-bit machine, can I use programs that are meant for 64-bit processors? I am using a 32-bit machine, but I am having to use a relatively obscure semantic database which only comes in 64-bit versions.  What are my options for running it in my local dev environment?  Currently when I try to run it, I get an error message that looks like this:  cannot execute binary file   and when I check my machine info, I get this:  $ uname -a Linux slabrams-desktop 2.6.32-29-generic #58-Ubuntu SMP Fri Feb 11 19:00:09 UTC 2011 i686 GNU/Linux Using a variable in a SELECT statement? public static void handleCaseComment(CaseComment caseComment) {    User[] users = [SELECT LastName FROM User WHERE Id = caseComment.CreatedById LIMIT 1]; }   This gives me the following error:  unexpected token: 'caseComment.CreatedById'   How do I use the value of the variable caseComment.CreatedById in a SELECT statement?