Tutorial by Examples: n

You can use either DOM Level 2 Core methods getAttribute(), getAttributeNS(), setAttribute(), and setAttributeNS() to read and write values from SVG elements, or you can use custom properties and methods specified in the SVG 1.1 IDL (Interface Definition Language). Simple Numeric Attributes For ex...
Using the mouse to drag an SVG element (or group of elements) can be accomplished by: Adding mousedown handler to starts the drag: adding a translation on the element to use during dragging (if needed), tracking mousemove events, and adding a mouseup handler to end the drag. During mousemove, tr...
# Set The Formatting $xmlsettings = New-Object System.Xml.XmlWriterSettings $xmlsettings.Indent = $true $xmlsettings.IndentChars = " " # Set the File Name Create The Document $XmlWriter = [System.XML.XmlWriter]::Create("C:\YourXML.xml", $xmlsettings) # Write the XML ...
The instance_eval method is available on all objects. It evaluates code in the context of the receiver: object = Object.new object.instance_eval do @variable = :value end object.instance_variable_get :@variable # => :value instance_eval sets self to object for the duration of the c...
Many languages feature a with statement that allows programmers to omit the receiver of method calls. with can be easily emulated in Ruby using instance_eval: def with(object, &block) object.instance_eval &block end The with method can be used to seamlessly execute methods on object...
All objects are instances of a class. However, that is not the whole truth. In Ruby, every object also has a somewhat hidden singleton class. This is what allows methods to be defined on individual objects. The singleton class sits between the object itself and its actual class, so all methods defi...
To detect multiple features at once, use the and operator. @supports (transform: translateZ(1px)) and (transform-style: preserve-3d) and (perspective: 1px) { /* Probably do some fancy 3d stuff here */ } There is also an or operator and a not operator: @supports (display: flex) or (display...
To better understand the semantics of conses and lists, a graphical representation of this kind of structures is often used. A cons cell is usually represented with two boxes in contact, that contain either two arrows that point to the car and cdr values, or directly the values. For instance, the re...
To consume a REST API with RestTemplate, create a Spring boot project with the Spring boot initialzr and make sure the Web dependency is added: <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dep...
The qsort() standard library function is a good example of how one can use void pointers to make a single function operate on a large variety of different types. void qsort ( void *base, /* Array to be sorted */ size_t num, /...
JSON_VALUE function enables you to take a data from JSON text on the path specified as the second argument, and use this value in any part of the select query: select ProductID, Name, Color, Size, Price, JSON_VALUE(Data, '$.Type') as Type from Product where JSON_VALUE(Data, '$.Type') = 'part' ...
Once JSON values are extracted from JSON text, you can use them ina any part of the query. You can create some kind of report on JSON data with grouping aggregations, etc: select JSON_VALUE(Data, '$.Type') as type, AVG( cast(JSON_VALUE(Data, '$.ManufacturingCost') as float) ) as cost from...
If some JSON text might not be properly formatted, you can remove those entries from query using ISJSON function. select ProductID, Name, Color, Size, Price, JSON_VALUE(Data, '$.Type') as Type from Product where JSON_VALUE(Data, '$.Type') = 'part' and ISJSON(Data) > 0
JSON_MODIFY function can be used to update value on some path. You can use this function to modify original value of JSON cell in UPDATE statement: update Product set Data = JSON_MODIFY(Data, '$.Price', 24.99) where ProductID = 17; JSON_MODIFY function will update or create Price key (if it do...
JSON_MODIFY function can be used to append new value to some array inside JSON: update Product set Data = JSON_MODIFY(Data, 'append $.tags', "sales") where ProductID = 17; New value will be appended at the end of the array, or a new array with value ["sales"] will be create...
If you have a "child table" formatted as JSON collection and stored in-row as JSON column, you can unpack this collection, transform it to table and join it with parent row. Instead of the standard JOIN operator, you should use CROSS APPLY. In this example, product parts are formatted as ...
In this example, Tags array may contain various keywords like ["promo", "sales"], so we can open this array and filter values: select ProductID, Name, Color, Size, Price, Quantity from Product CROSS APPLY OPENJSON(Data, '$.Tags') where value = 'sales' OPENJSON will op...
JSON is textual format, so it is stored in standard NVARCHAR columns. NoSQL collection is equivalent to two column key value table: CREATE TABLE ProductCollection ( Id int identity primary key, Data nvarchar(max) ) Use nvarchar(max) as you are not sure what would be the size of your JSON ...
Since JSON is stored textual column, you might want to ensure that it is properly formatted. You can add CHECK constraint on JSON column that checks is text properly formatted JSON: CREATE TABLE ProductCollection ( Id int identity primary key, Data nvarchar(max) CONSTRAINT [Data shoul...
You can expose values from JSON column as computed columns: CREATE TABLE ProductCollection ( Id int identity primary key, Data nvarchar(max), Price AS JSON_VALUE(Data, '$.Price'), Color JSON_VALUE(Data, '$.Color') PERSISTED ) If you add PERSISTED computed column, value from JSON tex...

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