Whenever I try to read about what are Hooks in Drupal, and how to manipulate forms or content with them, the text seem not to deal with the UI at all, but mostly with coding... Maybe I did not encounter the right reading material about UI-Hook relationship?  Can someone please detail in simple words and  a simple example?   What are Hooks? Do you use them via UI or only through Coding?  Do I need to know PHP to use a module such as Hook form-alter?
I am intermediate in PHP. To polish my skills I start learning Drupal 7. While learning Drupal architecture concepts, the terms hooks and bootstrapping puzzled me a lot. I read the "Pro Drupal development" book, and some documentation on drupal.org, but it is so advanced for me to learn how hooks work in Drupal to display the web page.  Can anyone tell me what hooks are in simple words?
What do the E and R prefixes stand for in the names of Intel 32-bit and 64-bit registers? What other languages have features and/or libraries similar to Perl's format? Proving Pascal's identity So I came across Pascal's identity: Prove that for any fixed $r\geq 1$, and all $n\geq r$, $$ \binom{n+1}{r}=\binom{n}{r}+\binom{n}{r-1}. $$  I know you can use basic algebra or even an inductive proof to prove this identity, but that seems really cumbersome. I was wondering if anyone had a "cleaner" or more elegant way of proving it. For example, I think the following would be a decent combinatorial proof.   Proof: Let $S$ be a set with $n+1$ elements, and consider some fixed $x\in S$. There are $\binom{n+1}{r}\;\; r$-subsets of $S$--count them according to whether or not they contain $x$: there are $\binom{n}{r}$ not containing $x$, (each formed by choosing $r$ of the remaining $n$ elements in $S\setminus\{x\}$), and there are $\binom{n}{r-1}\;\; r$-sets containing $x$, (each formed by selecting an additional $r-1$ elements in $S\setminus\{x\}$).   Is that right? Are there any other efficient ways of doing it? Why does C# disallow readonly local variables? Homework - set theory infinite union A question from my homework I'm having trouble understanding. We are given:  $A(1) = \{\varnothing\}$, $A(n+1) = A(n)\cup (A(n)\times A(n))$  $A=A(1)\cup A(2)\cup A(3)\cup \cdots \cup A(n)\cup A(n+1) \cup \cdots$ to infinity  The questions are:  1) show that $A\times A \subseteq A$  2) Is $A \times A = A$?  Thank you for your help.  I've tried writing $A(2)$ but it gets really complicated and I'm having trouble understanding what the sets are. Let alone solve the question. Okay setting the scene. I have three tables, (Table1, Table2 and DataTable) and I want to insert into Table1 and Table2 using DataTable as source. So for every row in DataTable I want a row in Table1 and Table2, and Table2 needs to have the inserted id (PK) from Table1...  If I were to do this...  INSERT INTO Table1 SELECT A, B, C FROM MyTable INSERT INTO Table2 SELECT IDENTITY_INSERT(), D, E, F FROM MyTable   I'd get the ID of the last inserted record into Table1.  Is a CURSOR or WHILE loop the only ways to do this? How do I pronounce "ratio 1:1"? How do I pronounce "ratio 1:1"?  Should I pronounce it "ratio 1 to 1"? Experience using dropdowns in-line of sentence "mad lib" style Do you have experience implementing text inputs or drop-downs in-line with other text or forms? Is this approach any better than just creating a separate field/label?  In the example below the user has the option to indicate when to be reminded again (in one, two, or three days). When they are reminded of an assignment, they simply get an email or text message. Show that one-sided limits always exist for a monotone function (on an interval) Search only for the currently active language So i've been working on a Page Object Model framework for a large web application for our current company. It's the first time i've made my own framework and implemented the page object model. Im using Ruby w/Capybara and Selenium-Webdriver for my language/driver of choice.  Currently i've divided each page (or obvious "section of the site") into a class file. This class file has methods for just about everything (or an API of sorts). The problem i've ran into is that I am literally writing a method for every single thing....and i've came across 2 ways people seem to do this:  Lets pretend for a section/page of the site is a widget creation form, the widget has a name/description and some sort of "type" dropdown. Also a save button to save the widget.  Option A (Which is what i've done so far): Make a method for each element (the save button, called save_widget, all the different inputs, etc...)  Option B: Have getter and setter methods for each element, then a larger method which uses these private getter and setter methods.   With Option A my test scripts end up being longer, and honestly not much different than using selenium calls themselves.   Option B would probably call one method (Such as create_widget which would pass in multiple items which that method would call all the smaller getter/setter methods). This would make the test script MUCH shorter and more abstracted. However the getter/setter methods would probably take more actual writing for the page objects themselves (but possibly easier to maintain).  Is there a certain style that favors one over the other? The more I think about it the more Option B seems better...but I wonder if in this case abstraction is a good thing. Why exactly can't a single resistor be used for many parallel LEDs? Execute shell commands in Python Can "who" as a relative pronoun sometimes be omitted? I work on a HP laptop plugged in most of the time, and after a few months the battery went off-duty.  Of course, I could remove the battery each time the laptop is plugged and replace it each time I must move to where no sockets are around. But I think that:   It would be really BORING! The computer would not avail itself of the useful backup power supply a battery can provide in case of black out.   It should simply switch off the battery charging when a safe power level is reached (i.e. 95%) and start recharging it, not every five minutes, but only under a certain safe threshold (i.e. 40% - 50%).  In its energy-saving profiles, Windows 7 only allows for setting up screen brightness, screen fadeout, screen deactivation and the suspension, not managing any charging issue.  Is there a way to accomplish this? How do I automatically restart docky after a crash? Found this when subscribing to jQuery tag. "unsubscribe | rss" is not shown correctly. How do I save/remember last-used window position and size for applications? Suppose we have a random variable $X \sim f(x|\theta)$. If $\theta_0$ were the true parameter, the the likelihood function should be maximized and the derivative equal to zero. This is the basic principle behind the maximum likelihood estimator.   As I understand it, Fisher information is defined as   $$I(\theta) = \Bbb E \Bigg[\left(\frac{\partial}{\partial \theta}f(X|\theta)\right)^2\Bigg ]$$  Thus, if $\theta_0$ is the true parameter, $I(\theta) = 0$. But if it $\theta_0$ is not the true parameter, then we will have a larger amount of Fisher information.   my questions    Does Fisher information measure the "error" of a given MLE? In other words, doesn't the existence of positive Fisher information imply my MLE can't be ideal?  How does this definition of "information" differ from that used by Shannon? Why do we call it information? When typing &lt; or &gt; in LaTeX and compiling with pdflatex, the less than and greater than symbols appear at upside down exclamation points. I'm not in math mode.