SEARCH KEYWORD -- EVENT LOOP

  Select top 3 values from each group in a table with SQL

Yesterday, my friend Liu Bing asked me a question about how to select top 3 values for each person in a database table using SQL. I think this question is interesting and it deserves some thoughts. Here I record down how to solve this issue. Assume we have a table which has two columns, one column contains the names of some people and the other column contains some values related to each person. One person can have more than one value. Each value has a numeric type. The question is we want to se...

   SQL,Correlated query,top 3     2013-05-23 03:21:25

  Advanced event registration models

On this page I explain the two advanced event registration models: W3C’s and Microsoft’s. Since neither is cross–browser supported, their use is, for the moment, deprecated. W3C and Microsoft have both developed their own event registration model to replace Netscape’s traditional model. Though I’m not impressed by the Microsoft model, W3C’s is very good, except for one crucial vagueness. Unfortunately few browsers support it at the moment. W3C W3Cââ‚...

   JavaScript,Event model,this,bubble,capturing     2011-12-27 09:20:44

  PHP to get long running process progress dynamically

Frequently in web applications, we may have a request to the back end system which may trigger a long running process such as searching huge amount of data or a long running database process. Then the front end webpage may hang and wait for the process to be finished. During this process, if we can provide the user some information about the progress of the back end process, it may improve user experience. Unfortunately, in web applications, this seems not an easy task because web scripting lang...

   AJAX,PHP,progress,long process,demo     2012-06-04 07:29:37

  Ensure triggering transitionend event in JavaScript

CSS3 Transition has been widely used in modern web app development to offer users animations. Traditionally animations of element in HTML are controlled by JavaScript. If fancy animation is desired, then third party plugins can be installed in browsers such as Flash, Silverlight, Java Applet etc. With CSS3, animations can be easily achieved like a charm. Transition is one of the many features provided by CSS3. It can be used to transit one element from one state to another state smoothly within ...

   CSS3 TRANSITION, TRANSITIONEND, FORCE FIRE TRANSITIONEND     2015-05-09 08:56:51

  Data from iPhone 5 event

Apple finally unveils iPhone 5 on an event at the Moscone Center in San Francisco. At the beginning of the event, Apple showed us some data. There will be 380 Apple Retail Stores opened across 13 countries Last year Apple Retail Store welcomed 83 million customers 7 million Mountain Lion upgrades since last month It ranked the first place in sales for Macbook Air in United States, it has 27% market share in July From April to July, 17 million iPads are sold 84 million iPads are sold until thi...

   Apple,iPhone 5,event,data     2012-09-12 21:26:03

  Macro to change text color conditionally in Excel

Macros are small but very powerful VBA programs in Microsoft Office software. They can help us complete some repeated tasks automatically. Today, I will show you one macro example which is to change the text color conditionally. The excel file has a work sheet which contains some records of request. I want to check the status of each request, if the status of a request is approved, the text color of the status should be green; if the status of a request is rejected, the text color of the status ...

   Macro,Excel,Text color,Conditionally     2012-07-07 12:53:28

  JavaScript finite state machine

Finite state machine is a very useful design model, it can be used to simulate many events in the world. In short, finite state machine has three features: Number of states is finite At any moment, one object can only be in one state In some condition, it will transfer from one state to another state In JavaScript, finite state machine can be applied in many places. For example, one menu element on a webpage. When the mouse hovers on the menu, the menu will show up, while the mouse moves away...

   JavaScript,Finite state machine,State     2013-09-02 11:00:57

  Implementation of +,-,*,/ with bitwise operator

There is a question asked on Stackoverflow : Divide a number by 3 without using *,/,+,-,% operators. This question is an Oracle interview question. Some people give excellent answers. You can go there and take a look. Usually we need to use bitwise operators to do this kind of implementations. Here I want to show you ways to implement +,-,*,/ with bitwise operators. A bitwise operation operates on one or more bit patterns or binary numerals at the level of their individual bits. It is a fast, pr...

   Bitwise operator,Shift,Add,Subtract,Multiplication,Division     2012-08-05 01:52:47

  Extension context menu is missing in Firefox after restart

If you have experience of writing Chrome extension, you may be familiar with how you can add a context menu for your extension. The code would be similar to below: chrome.runtime.onInstalled.addListener(function() { chrome.contextMenus.removeAll(); chrome.contextMenus.create({ "id": "your_id", "title": "Your Title", "contexts": ["all"] }); }); You need to add a listener listening to the extension install event. Once the extension is installed, create a contex...

   CHROME,FIREFOX,EXTENSION,CONTEXT MENU     2018-11-16 20:58:20

  What's Wrong with the For Loop

Closures in Java are a hot topic of late. A few really smart people are drafting a proposal to add closures to a future version of the language. However, the proposed syntax and the linguistic addition are getting a lot of push back from many Java programmers. Today, Elliotte Rusty Harold posted his doubts about the merits of closures in Java. Specifically, he asks "Why Hate the for Loop?": I don’t know what it is some people have against for loops that they’re so eager to...

   For loop,Basic,Problem,Efficiency,Java     2012-02-24 05:06:15

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