Tutorial by Examples: l

Imagine the following XML: <root> <element foobar="hello_world" /> <element example="this is one!" /> </root> /root/element[@foobar] and will return the <element foobar="hello_world" /> element.

Imagine the following XML: <root> <element foobar="hello_world" /> <element example="this is one!" /> </root> The following XPath expression: /root/element[@foobar = 'hello_world'] will return the <element foobar="hello_world&quo...

Let's say you don't want the fields houseNum and street in the address field of the final populated doc, use the populate() as follows, Person.findOne({_id: req.params.id}) .populate('address', '-houseNum -street') // note the `-` symbol .exec(function(err, person) { // do somet...

If you only want the fields houseNum and street in the address field in the final populated doc, use the populate() function as follows in the above two methods, Person.findOne({_id: req.params.id}) .populate('address', 'houseNum street') .exec(function(err, person) { // do somet...

Assuming that you are running redis server on localhost you can type command redis-cli After this command appear redis command line prompt 127.0.0.1:6379>

If the built in attributes are not sufficient to validate your model data, then you can place your validation logic in a class derived from ValidationAttribute. In this example only odd numbers are valid values for a model member. Custom Validation Attribute public class OddNumberAttribute : Valid...

How do you handle errors, rather then log them to the console? Bad way: Router.route('/') .get((req, res) => { Request.find((err, r) => { if(err){ console.log(err) } else { res.json(r) } }) }) .post((req, res) => { const reque...

The simplest way to write a parser is to use the recursive descent technique. This creates a top-down parser (which may formally be described a LL(1)). To start the example we first have to establish the grammar rules for our language. In this example we will use simple arithmetic expression assignm...

The following example is a very useful basis when you are trying to convert transaction data to un-pivoted data for BI/reporting reasons, where the dimensions which are to be un-pivoted can have a dynamic set of columns. For our example, we suppose that the raw data table contains employee assessme...

When sending a notification to an iOS device, you must set priority: "high" for it to wake up. Otherwise, the notification will not be received while the phone is asleep. Sets the priority of the message. Valid values are "normal" and "high." On iOS, these correspond...

OpenCL is low level api so it must be implemented in "C space" first. For that, one needs to download header files from Khronos' site. My hardware is AMD and capable of version 1.2, downloading opencl.h cl_platform.h cl.h cl_ext.h cl_egl.h cl_dx9_media_sharing.h cl_d3d10.h c...

### Elixir ### /_build /cover /deps erl_crash.dump *.ez ### Erlang ### .eunit deps *.beam *.plt ebin rel/example_project .concrete/DEV_MODE .rebar

mongodump --db mydb --gzip --out "mydb.dump.$(date +%F_%R)" This command will dump a bson gzipped archive of your local mongod 'mydb' database to the 'mydb.dump.{timestamp}' directory

mongorestore --db mydb mydb.dump.2016-08-27_12:44/mydb --drop --gzip This command will first drop your current 'mydb' database and then restore your gzipped bson dump from the 'mydb mydb.dump.2016-08-27_12:44/mydb' archive dump file.

XML <Dashavatar> <Avatar name="Matsya"/> <Avatar name="Kurma"/> <Avatar name="Varaha"/> <Avatar name="Narasimha"/> <Avatar name="Vamana"/> <Avatar name="Balabhadra"/> ...

XML <Dashavatar> <Avatar name="Matsya"/> <Avatar name="Kurma"/> <Avatar name="Varaha"/> <Avatar name="Narasimha"/> <Avatar name="Vamana"/> <Avatar name="Balabhadra"/> ...

XML <Dashavatar> <Avatar name="Matsya"/> <Avatar name="Kurma"/> <Avatar name="Varaha"/> <Avatar name="Narasimha"/> <Avatar name="Vamana"/> <Avatar name="Balabhadra"/> ...

XML <House> <Rooms>10</Rooms> <People>4</People> <TVs>4</TVs> <Floors>2</Floors> </House> XPATH /House/child::node() OUTPUT <Rooms>10</Rooms> <People>4</People> <TVs>4</TVs&gt...

XML <House> <numRooms>4</numRooms> <Room name="living"/> <Room name="master bedroom"/> <Room name="kids' bedroom"/> <Room name="kitchen"/> </House> XPATH /House/child::Room or /...

XML <House> <numRooms>4</numRooms> <Floor number="1"> <Room name="living"/> <Room name="kitchen"/> </Floor> <Floor number="2"> <Room name="master bedroom&qu...