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context.globalAlpha=0.50 You can change the opacity of new drawings by setting the globalAlpha to a value between 0.00 (fully transparent) and 1.00 (fully opaque). The default globalAlpha is 1.00 (fully opaque). Existing drawings are not affected by globalAlpha. // draw an opaque rectangle co...

To begin, npm install the desired loaders for your project. Inside of the configuration object that is being exported in webpack.config.js, a module property will hold all of your loaders. const source = `${__dirname}/client/src/`; module.exports = { // other settings here module: { ...

With an input password type, you can also enable an icon that can show or hide the entire text using the passwordToggleEnabled attribute. You can also customize same default using these attributes: passwordToggleDrawable: to change the default eye icon passwordToggleTint: to apply a tint to the...

You can re-throw error that you catch in CATCH block using TRHOW statement: DECLARE @msg nvarchar(50) = 'Here is a problem! Area: ''%s'' Line:''%i''' BEGIN TRY print 'First statement'; RAISERROR(@msg, 11, 1, 'TRY BLOCK', 2); print 'Second statement'; END TRY BEGIN CATCH print...

You can throw exception in try catch block: DECLARE @msg nvarchar(50) = 'Here is a problem!' BEGIN TRY print 'First statement'; THROW 51000, @msg, 15; print 'Second statement'; END TRY BEGIN CATCH print 'Error: ' + ERROR_MESSAGE(); THROW; END CATCH Exception with be ...

Let's say you have a library that returns callbacks, for example the fs module in NodeJS: const fs = require("fs"); fs.readFile("/foo.txt", (err, data) => { if(err) throw err; console.log(data); }); We want to convert it to a promise returning API, with bluebird - ...

var firstItem = fetch("/api1").then(x => x.json()); var secondItem = fetch("/api2").then(x => x.json()); Promise.all([firstItem, secondItem]).spread((first, second) => { // access both results here, both requests completed at this point });

The PHP community has a lot of developers creating lots of code. This means that one library’s PHP code may use the same class name as another library. When both libraries are used in the same namespace, they collide and cause trouble. Namespaces solve this problem. As described in the PHP referenc...

configuration EnableIISFeature { node localhost { WindowsFeature IIS { Ensure = “Present” Name = “Web-Server” } } } If you run this configuration in Powershell (EnableIISFeature), it will produce a localho...

Passwords should never be stored as plain text! They should be hashed with a randomly generated salt (to defend against rainbow table attacks) using a slow password hashing algorithm. A high number of iterations (> 10k) can be used to slow down brute force attacks. A delay of ~100ms is acceptable...

import XCTest @testable import PersonApp class PersonTests: XCTestCase { func test_completeName() { let person = Person(firstName: "Josh", lastName: "Brown") XCTAssertEqual(person.completeName(), "Josh Brown") } } Now let's discuss wh...

Adding tags to "describe" or "it" blocks allows you to run only those examples with a given tag. Use the --tag (or -t) option to run examples that match a specified tag. The tag can be a simple name or a name:value pair. If a simple name is supplied, only examples with :name...

If you are only adding new rows in your RDBMS (not updating existing data) You need two additional parameters: --check-column : A column name that should be checked for newly appended data. Integer would be a suitable data type for this column. --last-value : The last value that successfully im...

If you are adding new rows and updating existing data. You need two additional parameters: --check-column : A column name that should be checked for newly appended and updated data. date, time, datetime and timestamp are suitable data types for this column. --last-value : The last value that su...

file:write_file("myfile.txt", ["Hi " [<<"there">>], $\n]).

["Guten Tag " | [<<"Hello">>]]. [<<"Guten Tag ">> | [<<"Hello">>]]. [$G, $u, $t, $e, $n , $T, $a, $g | [<<"Hello">>]]. [71,117,116,101,110,84,97,103,<<"Hello">>].

["Guten tag " | <<"Hello">>]. In the shell this will be printed as ["Guten tag "|<<"Hello">>] instead of ["Guten tag ",<<"Hello">>]. The pipe operator will create an improper list if the last element o...

The following example uses allow and receive to stub a Cart's call to a CreditCardService so that the example doesn't have to wait for a network call or use a credit card number that the processor knows about. class Cart def check_out begin transaction_id = CreditCardService.instance...

The following example uses expect and receive to mock an Order's call to a CreditCardService, so that the test passes only if the call is made without having to actually make it. class Order def cancel CreditCardService.instance.refund transaction_id end end describe Order do des...

HTML: <div class="container"> <div class="child"></div> </div> CSS: .container { height: 500px; width: 500px; display: flex; // Use Flexbox align-items: center; // This centers children vertically in the parent. ...