Tutorial by Examples: d

Update an existing model

$user = User::find(1); $user->name = 'abc'; $user->save(); You can also update multiple attributes at once using update, which does not require using save afterwards: $user = User::find(1); $user->update(['name' => 'abc', 'location' => 'xyz']); You can also update a model(s)...

Throw 404 if entity not found

If you want to automatically throw an exception when searching for a record that isn't found on a modal, you can use either Vehicle::findOrFail(1); or Vehicle::where('make', 'ford')->firstOrFail(); If a record with the primary key of 1 is not found, a ModelNotFoundException is thrown. W...

Reading and writing DataObjects

DataObjects in SilverStripe represent a database table row. The fields in the model have magic methods that handle getting and setting data via their property names. Given we have a simple DataObject as an example: class Fruit extends DataObject { private static $db = ['Name' => 'Varchar'...

A View Bound to Existing HTML

Assuming this HTML in the page: <body> <div id="myPage"> </div> </body> A view can be bound to it with: var MyPageView = Backbone.View.extend( { "el": "#myPage", "template": _.template( "<p>This is m...

Defining Variadic Functions

A Clojure function can be defined to take an arbitrary number of arguments, using the symbol & in its argument list. All remaining arguments are collected as a sequence. (defn sum [& args] (apply + args)) (defn sum-and-multiply [x & args] (* x (apply + args))) Calling: =&gt...

Use Format to convert and format a numeric type as a string

Const zipCode As long = 10012 Dim zeroPaddedNumber As String zeroPaddedZipCode = Format(zipCode, "00000000") 'zeroPaddedNumber = "00010012"

Reload NGINX configuration file

As a root user: sudo nginx -s reload Ubuntu 14.04 example sudo service nginx reload Ubuntu 16.04 example sudo systemctl reload nginx Before reloading, it is a good idea to check config for syntax errors: sudo nginx -t Or sudo service nginx configtest

Shutdown NGINX

Run as a root user. Fast shutdown: nginx -s stop Graceful shutdown: nginx -s quit

Using LocalBroadcastManager

LocalBroadcastManager is used to send Broadcast Intents within an application, without exposing them to unwanted listeners. Using LocalBroadcastManager is more efficient and safer than using context.sendBroadcast() directly, because you don't need to worry about any broadcasts faked by other Applic...

AES encryption of data using password in a secure way

The following example encrypts a given data block using AES. The encryption key is derived in a secure way (random salt, 1000 rounds of SHA-256). The encryption uses AES in CBC mode with random IV. Note that the data stored in the class EncryptedData (salt, iv, and encryptedData) can be concatenate...

Filter items inside RecyclerView with a SearchView

add filter method in RecyclerView.Adapter: public void filter(String text) { if(text.isEmpty()){ items.clear(); items.addAll(itemsCopy); } else{ ArrayList<PhoneBookItem> result = new ArrayList<>(); text = text.toLower...

Separating distribution specific tasks and variables inside a role

We can easily separate distribution specific tasks and variables into different dedicated .yml files. Ansible helps us to automatically identify the target hosts distribution via {{ ansible_distribution }} and {{ ansible_distribution_version }}, so we just have to name the distribution dedicated .y...

SSL/TLS in Node.js

If you choose to handle SSL/TLS in your Node.js application, consider that you are also responsible for maintaining SSL/TLS attack prevention at this point. In many server-client architectures, SSL/TLS terminates on a reverse proxy, both to reduce application complexity and reduce the scope of secur...

Redux-thunk: basics

While redux itself is entirely synchronous, you can use a middleware such as redux-thunk to handle asynchronous actions. A "thunk" is another name for a callback. It is a function that is usually passed as an argument to be called at a later time. To use, apply the middleware to you...

Using an httpHandler (.ashx) to download a file from a specific location

Create a new httpHandler inside your ASP.NET project. Apply the following code (VB) to the handler file: Public Class AttachmentDownload Implements System.Web.IHttpHandler Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest ' pass an ID thr...

Using redux-thunk with jQuery.ajax

const loadUser = userId => dispatch => { dispatch({ type: 'USER_LOADING' }); $.ajax('/users/' + userId, { type: 'GET', dataType : 'json' }).done(response => { dispatch({ type: 'USER_LOADED', user: response }); }).fail((xhr, status, error) =>...

Using Bundling / Minification

The way the $scope is injected in the controller's constructor functions is a way to demonstrate and use the basic option of angular dependency injection but is not production ready as it cannot be minified. Thats because the minification system changes the variable names and anguar's dependency i...

Simple try..finally example to avoid memory leaks

Use try-finally to avoid leaking resources (such as memory) in case an exception occurs during execution. The procedure below saves a string in a file and prevents the TStringList from leaking. procedure SaveStringToFile(const aFilename: TFilename; const aString: string); var SL: TStringList; ...

Use InStr to determine if a string contains a substring

Const baseString As String = "Foo Bar" Dim containsBar As Boolean 'Check if baseString contains "bar" (case insensitive) containsBar = InStr(1, baseString, "bar", vbTextCompare) > 0 'containsBar = True 'Check if baseString contains bar (case insensitive) co...

Use InStr to find the position of the first instance of a substring

Const baseString As String = "Foo Bar" Dim containsBar As Boolean Dim posB As Long posB = InStr(1, baseString, "B", vbBinaryCompare) 'posB = 5

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