Tutorial by Examples: w

With XML::Rabbit it is possible to consume XML files easily. You define in a declarative way and with an XPath syntax what you are looking for in the XML and XML::Rabbit will return objects according to the given definition. Definition: package Bookstore; use XML::Rabbit::Root; has_xpath_object_...

I always think it is nice to have a very simple, self-contained example so that nothing is assumed when I am learning a new task. This answer is that for deleting UITableView rows. The project performs like this: This project is based on the UITableView example for Swift. Add the Code Create a ...

If you're going to be designing layouts with fixed size screens for different mobile devices, you may want to mirror that design when running your app on a desktop. The following method fixes the size of the window OUTSIDE of PhoneGap, giving a fixed-sized window on the desktop. Sometimes it's easie...

You'll need to separate out your application layer from your database layer, and that means specifying the MONGO_URL. Which means running your app through the bundle command, uncompressing it, setting environment variables, and then launching the project as a node app. Here's how... #make sure you...

Same thing as before, but you have to copy the info into the mongodump command. You have to run the following commands rediculously fast, and it requires hand/eye coordination. Be warned! This is a rediculously hacky! But fun! Think of it as a video game! :D # get the MONGO_URL string for your app ...

Mongo supports database-to-database copying, which is useful if you have large databases on a staging database that you want to copy into a local development instance. // run mongod so we can create a staging database // note that this is a separate instance from the meteor mongo and minimongo ins...

db.posts.find().forEach(function(doc){ if(doc.oldField){ db.posts.update({_id: doc._id}, {$set:{'newField':doc.oldField}}, false, true); } });

db.posts.find().forEach(function(doc){ if(doc.commenters){ var firstCommenter = db.users.findOne({'_id': doc.commenters[0]._id }); db.clients.update({_id: doc._id}, {$set:{'firstPost': firstCommenter }}, false, true); var firstCommenter = db.users.findOne({'_id': do...

db.posts.find().forEach(function(doc){ if(doc.foo === 'bar'){ db.posts.update({_id: doc._id}, {$set:{'foo':'squee'}}, false, true); } });

This project is a self-contained example done completely in the Interface Builder. You should be able to work through it in 10 minutes or less. Then you can apply the concepts you learned to your own project. Here I just use UIViews but they can represent whatever view you like (ie, button, label...

Using Dynamic Arrays in VBA can be quite clunky and time intensive over very large data sets. When storing simple data types in a dynamic array (Strings, Numbers, Booleans etc.), one can avoid the ReDim Preserve statements required of dynamic arrays in VBA by using the Split() function with some cl...

Use $state.transitionTo to go form one state to another. This is a low level method to transition and $state.go is the recommended way for most common use cases as it uses this method internally. $state.transitionTo(toState [, toParams] [, options]) toState - the state to transition to toPara...

Webhook Overview A WebHook is an HTTP callback: an HTTP POST that occurs when something happens; a simple event-notification via HTTP POST. A web application implementing WebHooks will POST a message to a URL when certain things happen. PubNub Presence Pubnub presence all about the user prese...

For programs with a single source file, using gcc is simple. /* File name is hello_world.c */ #include <stdio.h> int main(void) { int i; printf("Hello world!\n"); } To compile the file hello_world.c from the command line: gcc hello_world.c gcc will then compil...

There are three ways to set the classpath. It can be set using the CLASSPATH environment variable : set CLASSPATH=... # Windows and csh export CLASSPATH=... # Unix ksh/bash It can be set on the command line as follows java -classpath ... javac -classpath ... Note ...

The content mode property of a view tells how its content should be laid out. In the Interface Builder, the various modes can be selected in the Attributes Inspector. Let's use two image views to see how the various modes work. Scale to Fill The image heights and widths are stretched to mat...

Create a new project It can be just a Single View Application. Add the code Create a new Cocoa Touch Class file (File > New > File... > iOS > Cocoa Touch Class). Name it MyCollectionViewCell. This class will hold the outlets for the views that you add to your cell in the storyboard. ...

Using generics to define the type in instanceof Consider the following generic class Example declared with the formal parameter <T>: class Example<T> { public boolean isTypeAString(String s) { return s instanceof T; // Compilation error, cannot use T as class type here ...

The following might have undefined behavior due to incorrect pointer alignment: char *memory_block = calloc(sizeof(uint32_t) + 1, 1); uint32_t *intptr = (uint32_t*)(memory_block + 1); /* possible undefined behavior */ uint32_t mvalue = *intptr; The undefined behavior happens as the pointer...

An extension to PHP called Xdebug is available to assist in profiling PHP applications, as well as runtime debugging. When running the profiler, the output is written to a file in a binary format called "cachegrind". Applications are available on each platform to analyze these files. To...