I have a parent-child LWC: &lt;template&gt;     &lt;template if:true={isInitialized}&gt;         &lt;lightning-layout multiple-rows=&quot;false&quot;&gt;             &lt;template if:true={showCustomerQuote}&gt;                 &lt;lightning-layout-item size=&quot;6&quot;&gt;                     &lt;c-customer-quote-builder record-id={customerLoadId}                                                object-api-name={objectApiName}                                                customer-load-list={customerLoadList}                                               oncustomerloadchanged={customerLoadChangedHandler}                                               onaddtocarrierquote={addToCarrierQuoteHandler}&gt;&lt;/c-customer-quote-builder&gt;                 &lt;/lightning-layout-item&gt;             &lt;/template&gt;             &lt;template if:true={showCarrierQuote}&gt;                 &lt;lightning-layout-item size=&quot;6&quot;&gt;                     &lt;c-carrier-quote-builder record-id={carrierLoadId}                                               object-api-name={objectApiName}                                               carrier-load-list={carrierLoadList}                                              oncarrierquotechanged={carrierQuoteChangedHandler}                                              onaddtocustomerquote={addToCustomerQuoteHandler}&gt;&lt;/c-carrier-quote-builder&gt;                 &lt;/lightning-layout-item&gt;             &lt;/template&gt;         &lt;/lightning-layout&gt;     &lt;/template&gt; &lt;/template&gt;  I want the child to send an event to the parent, which changes @api parameters on the same child: Child Event Dispatcher: customerLoadChanged(event) {     const e = new CustomEvent('customerloadchanged', { detail: { loadId: event.target.value }});     this.dispatchEvent(e);                     }  Parent Event Handler changes @api parameter on the child who sent the event: customerLoadChangedHandler(event) {     this.customerLoadId = event.detail.loadId; }  Event though customerLoadId/recordId is an @api parameter on the child the child does not re-render: @api recordId;                                  // Load__c or CustomerQuote__c Id  Why doesn't the update of an @api parameter by a parent pushed to a child NOT redraw the child?? Thanks.
Let's say we have this code for a LWC:  &lt;!-- helloExpressions.html --&gt; &lt;template&gt;     &lt;div class="slds-m-around_medium"&gt;         &lt;lightning-input name='firstName' label="First Name" onchange={handleChange}&gt;&lt;/lightning-input&gt;         &lt;lightning-input name='lastName' label="Last Name" onchange={handleChange}&gt;&lt;/lightning-input&gt;         &lt;p class="slds-m-top_medium"&gt;Uppercased Full Name: {uppercasedFullName}&lt;/p&gt;     &lt;/div&gt; &lt;/template&gt;   and this is the JS file:  // helloExpressions.js import { LightningElement, track } from 'lwc';  export default class HelloExpressions extends LightningElement {     @track firstName = '';     @track lastName = '';      handleChange(event) {         const field = event.target.name;         if (field === 'firstName') {             this.firstName = event.target.value;         } else if (field === 'lastName') {             this.lastName = event.target.value;         }     }      get uppercasedFullName() {         return `${this.firstName} ${this.lastName}`.toUpperCase();     } }   firstName and lastName have been decorated with @track. Now as per the documentation, decorating a property with @track makes it private and reactive, while to mark a property public and reactive, use @api.  So if I just change the decorator to @api for both these variables, it should work. I am referring these from the same component only. But it's not working.  UPDATE: 27th Feb -------------------- Somehow it's working today. I just changed the decorator of the variables to api.  import { LightningElement, api } from 'lwc';  export default class HelloExpressions extends LightningElement {     @api firstName = '';     @api lastName = '';      handleChange(event) {         const field = event.target.name;         if (field === 'firstName') {             this.firstName = event.target.value;         } else if (field === 'lastName') {             this.lastName = event.target.value;         }     }      get uppercasedFullName() {         return `${this.firstName} ${this.lastName}`.toUpperCase();     } }   So it's working.
Does one work in or on an aeroplane? Discrepency in unanswered questions counts On , I notice that if I use the lower &quot;unanswered&quot; tab (the one in line with &quot;All Questions&quot;), the count is 1,432 questions. If I use the upper &quot;Unanswered&quot; tab (in line with the site title), I get 1,383 &quot;questions with no upvoted or accepted answers&quot;.  This changes the options in the lower tab, one of which is &quot;no answers&quot;.  Clicking here, I now get 1,083 &quot;questions with no answers&quot;. If I run select Id from Posts where PostTypeId=1 and AnswerCount=0;  in the , I get 1158 rows back. Which of these is correct, and why is the first one (1,432) so much higher than the others?  I understand that the numbers may only be updated periodically, but that difference in particular seems much too great for this to be the reason. To clarify:  1,432 is the number of &quot;unanswered questions&quot;. 1,383 is the number of &quot;questions with no upvoted or accepted answers&quot;. 1,083 is the number of &quot;questions with no answer&quot; 1,158 is the number of questions with no answer in the data explorer.  This is not live data, but that means it should be smaller, not larger, than 1,083.  I promise we did not offset this with answers to the tune of 80 questions this week.  The first three are obviously live because they fluctuate. The difference between the first two is ~50, implying they actually don't refer to the same thing, and the difference between the last two seems too great (and in the wrong direction) to be explained by the a live vs. data explorer source. Taking Seats on a Plane This is a neat little problem that I was discussing today with my lab group out at lunch. Not particularly difficult but interesting implications nonetheless  Imagine there are a 100 people in line to board a plane that seats 100. The first person in line realizes he lost his boarding pass so when he boards he decides to take a random seat instead. Every person that boards the plane after him will either take their "proper" seat, or if that seat is taken, a random seat instead.  Question: What is the probability that the last person that boards will end up in his/her proper seat.  Moreover, and this is the part I'm still pondering about. Can you think of a physical system that would follow this combinatorial statistics? Maybe a spin wave function in a crystal etc... If you cast Blindness/Deafness as a 3rd level spell, can you target one creature with both effects? What do you call a person who keeps talking about art; studies art, criticizes art, and thinks he'd be amazing with it. But he doesn't practice it Press-and-hold or Long-Press Gestures: Unintuitive? Often, I find people struggle with the usage of press-and-hold gestures on mobile/web platforms. The mere thought of having a user press on a defined object and hold for an arbitrary amount of time before the product reacts seems overtly complicated and unobtrusive. My questions are:   For what use cases do press-and-hold gestures best fit? Have there been published studies with regards to press-and-hold gesture intuition? Are there more viable alternatives to this system? I am under DDoS. What can I do? Contemporary written usage of "whom" in objective case Possible Duplicate:          I was writing a LinkedIn recommendation one day, and ended up pondering for a while which of these forms to use:     … is a great developer whom I always   found easy to work with.      … is a great developer who I always   found easy to work with.   Both are basically correct in contemporary English, right? But is one or the other preferable, and if so, why?   (In this case I went with the latter, as it seemed more common (Google)  and I wanted to avoid sounding unnecessarily “archaic”, although I’m not sure whether that would have been the case. Also note that I try to write in a “friendly professional” style instead of overly formal one. :-) One Time Pad Key Distribution For multiple OTP keys, why not do this:  Key = Hash[(EC)DH Shared Secret + Counter]  The counter will increase per message, and the output of the hash will be random for each new unique input into it. What are the problems or weaknesses with this design??  EDIT: For clarification: both parties will have the shared secret from an ECDH exchange, random numbers from Pythons os.urandom for generating the ECC key At page 17 of Munkres' Elements of Algebraic topology it says, referring to fig. 3.6, that "the diagram does not determine [the torus]. It does more than paste opposite edges together":   Is it so? I tried to glue them together, but end up with a normal torus. There is a remote Windows server on a private network which I can connect to via Remote Desktop Connection.  I would like to be able to make TCP/IP connections from my computer to other computers on that server's network.  Remote Desktop Connection makes it possible to share printers, drives, and other local resources through the connection.  Is there any way to "tunnel" a TCP/IP connection via RDC?  I'd like something similar to the port-forwarding provided by SSH.  I don't see any way to do this via RDC, but I'm hoping the capability is there and I just don't know about it. How and why do normalization and feature scaling work? I see that lots of machine learning algorithms work better with mean cancellation and covariance equalization. For example, Neural Networks tend to converge faster, and K-Means generally gives better clustering with pre-processed features. I do not see the intuition behind these pre-processing steps lead to improved performance. Can someone explain this me? What are the minimum requirements to run Windows 10? I am looking to upgrade my system to Windows 10 RTM, but I'm afraid of losing performance.  I researched on the site but found details (maybe I have not sought duty) on the hardware minimum.  What are the minimum and recommended requirements for running Windows 10 RTM? How can I change wallpaper automatically? I have found a guide for that but doesn't sure if it will work or it is safe to use. The guide:  I am asking if is these introductions safe and will work? If not, is there any other solutions for that? I am using Ubuntu 20.04 LTS Thank you. "To delete" is to "deletion" as "to discard" is to what? "To delete" is to "deletion" as "to discard" is to what? Showing that $A\cap B = A\setminus (A\setminus B)$ How does one show that $A\cap B = A\setminus (A\setminus B)$?  My thinking is that if $x\in A\setminus (A\setminus B)$ then this means that $x\in A$ and $x\notin A\setminus B$, which means that $x\in A$ and ($x\notin A$ and $x\in B$), but I don't see why the expression in parentheses should simplify to just $x\in B$. Any insight would be helpful.  Maybe $(x\in A^c$ and $x\in B)$, i.e, $x\in A^c\cap B$ is a possible simplification of the expression in parentheses, but still don't see why this simplifies to just $x\in B$. How to read off coefficients of tensor-like expression in a speedy way? When is "seems to be" used instead of "seems"? The baby seems happy/comfortable. The baby seems to be happy/comfortable.   Are these both correct? If both are correct, what are the differences between them? I've recently read a  from a local paper that included the following:     The pair was drinking prior to the shooting.   To me, this appears wrong and I would say that the proper way to make the statement would be:     The pair were drinking prior to the shooting.   Is the original article correct? A real solution to ambiguous tags Introduction Even within a site's relatively focused range of topics (it's unlikely anybody on SO will think  refers to the solar system's star), some tags are inherently ambiguous. There are currently two unsatisfying options:  Declare that the tag is only to be used for one of the possible meanings, write a tag wiki explaining it, and link from there to the newly created tags for the other meanings, and keep cleaning up the tag whenever someone ignores the tag wiki popup explaining the tag. Use alternative tags for all meanings (e.g. cd-command and compact-disk, instead of cd), and keep removing the undesired tag whenever it pops up again. And it will. The  is not deterring users from creating unnecessary or redundant tags.  Blacklisting tags is a complicated ritual occurring once in a blue moon, at most, and involves a dragon, a team member, and sacrifices to be burnt. It also makes those other, unambiguous tags not easier to discover, if it were applied to ambiguous tags. I don't consider this to be a viable option in this case. Proposal Here's the proposed : Just like a tag can be declared a synonym of another tag, basically changing all references to the synonym to references to that other, canonical tag, it should be possible to make it a disambiguation tag (or ambiguous tag) for multiple other tags. It's a logical progression from &quot;You entered a term with the same meaning as this other term&quot; to &quot;You entered a term with the same meaning as one of these other terms, please choose the correct meaning&quot;. Use of the tag should force the user to choose one of the alternatives presented:  &quot;, did you mean  or ?&quot; &quot;, did you mean , , or ?&quot; &quot;You entered 'vm', did you mean  or ?&quot; &quot;You entered 'sas', did you mean  or ?&quot; &quot;You entered 'kvm', did you mean  or ?&quot; &quot;You entered 'mono', did you mean  or ?&quot; &quot;You entered 'dsl', did you mean  or ?&quot;  Not all of these examples might be good (I'm not sure e.g. about the first two SO examples), but that's not really the point here anyway — they should just convey how this could be used. Note how some of these tags would probably never be used if users had to type them, and yet everything shorter is ambiguous. This could probably be mostly solved by extending the synonym/tag wiki excerpt dropdowns shown when a user enters the tags, proposing the alternatives for an ambiguous tag entered by the user (like a synonym suggestion, but with multiple options). If ignored, the user could still be shown an error message like with blacklisted tags, but by designing the selection dialog well, it should be possible to prevent that in most cases.  Related topics   This topic is related, but the user seems to have accepted the inclusion of tag wiki excerpts in the tag suggestions drop-down as sufficient.   This requires extensive discussion and team involvement (i.e. the status quo)   This topic has no real solution, except manual retagging.