Tutorial by Examples: ch

After your service worker is registered, the browser will try to install & later activate the service worker. Install event listener this.addEventListener('install', function(event) { console.log('installed'); }); Caching One can use this install event returned to cache the assets ne...

Character escaping is what allows certain characters (reserved by the regex engine for manipulating searches) to be literally searched for and found in the input string. Escaping depends on context, therefore this example does not cover string or delimiter escaping. Backslashes Saying that backsla...

Sometimes you doesn't want to simply replace or remove the string. Sometimes you want to extract and process matches. Here an example of how you manipulate matches. What is a match ? When a compatible substring is found for the entire regex in the string, the exec command produce a match. A match i...

Some regex engines (such as .NET) can handle context-free expressions, and will work it out. But that's not the case for most standard engines. And even if they do, you'll end up having a complex hard-to-read expression, whereas using a parsing library could make the job easier. How to find all p...

"The :nth-child(an+b) CSS pseudo-class matches an element that has an+b-1 siblings before it in the document tree, for a given positive or zero value for n" - MDN :nth-child pseudo-selector12345678910:first-child✔:nth-child(3)✔:nth-child(n+3)✔✔✔✔✔✔✔✔:nth-child(3n)✔✔✔:nth-child(3n+1)...

This program demonstrates how to run another process using fork() and wait its termination using waitpid(): fork() creates an identical copy of the current process. The original process is the parent process, while the newly created one is the child process. Both processes continue exactly afte...

The command :g/apples/y A will yank all lines containing the word apples into the a register, which can be pasted with "ap. Any regular expression can be used. Note the space before the A, and the capitalization of the register letter. If a capital letter is used as the yank register, matc...

SELECT s.name AS [schema], t.object_id AS [table_object_id], t.name AS [table_name], c.column_id, c.name AS [column_name], i.name AS [index_name], i.type_desc AS [index_type] FROM sys.schemas AS s INNER JOIN sys.tables AS t ON s.schema_id = t.schema_id I...

Whenever you change data, in a Data Manipulation Language(DML) command, you can wrap your changes in a transaction. DML includes UPDATE, TRUNCATE, INSERT and DELETE. One of the ways that you can make sure that you're changing the right data would be to use a transaction. DML changes will take a loc...

USE msdb Go SELECT dbo.sysjobs.Name AS 'Job Name', 'Job Enabled' = CASE dbo.sysjobs.Enabled WHEN 1 THEN 'Yes' WHEN 0 THEN 'No' END, 'Frequency' = CASE dbo.sysschedules.freq_type WHEN 1 THEN 'Once' WHEN 4 THEN 'Daily' ...

USE AdventureWorks2012; GO CREATE FULLTEXT INDEX ON Production.Document ( Title Language 1033, DocumentSummary Language 1033, Document TYPE COLUMN FileExtension Language 1033 ) KEY INDEX PK_Document_DocumentID ...

SELECT product_id FROM products WHERE CONTAINS(product_description, ”Snap Happy 100EZ” OR FORMSOF(THESAURUS,’Snap Happy’) OR ‘100EZ’) AND product_cost < 200 ; SELECT candidate_name,SSN FROM candidates WHERE CONTAINS(candidate_resume,”SQL Server”) AND candidate_division ...

Steps to Reproduce (Turbo Forms, CRM 2015.1, --> CRM 2016.2) Form (with or without other required fields) has one field that is empty and required. Lose focus on the empty field ("title" in this example), this triggers the Field Notification Icon: Wire up onChange Handler for emp...

Enable utf8 pragma In order to enable utf8 pragma in one-liner, perl interpreter should be called with -Mutf8 option: perl -Mutf8 -E 'my $人 = "human"; say $人' Unicode handling with -C switch The -C command line flag lets you control Unicode features. It can be followed by a list of o...

When rendering a form 'by hand', it can be useful to know if there are fields left to render or not. The function isRendered() from the FormView class returns true if there are still fields left to be rendered to the template. This snippet prints <h3>Extra fields</h3> if there are fiel...

There are dozens of character sets with hundreds of collations. (A given collation belongs to only one character set.) See the output of SHOW COLLATION;. There are usually only 4 CHARACTER SETs that matter: ascii -- basic 7-bit codes. latin1 -- ascii, plus most characters needed for Western Eur...

You can rename branch in local repository using this command: git branch -m old_name new_name

As a developer, you frequently find yourself dealing with strings that are not created by your own code. These will often be supplied by third party libraries, external systems, or even end users. Validating strings of unclear provenance is considered to be one of the hallmarks of defensive program...

A cached query is a query that has its results stored in the server's memory. The results are stored when the query is first run. From then on, whenever that query is requested again, ColdFusion will retrieve the results from memory. You can cache a query using the cachedAfter attribute. If the que...

create destination with <a id="destinationLinkName"></a> link to destination [link text](#destinationLinkName)