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After following the instructions above and installing Leiningen, start a new project by running: lein new <project-name> This will setup a Clojure project with the default Leiningen template within the <project-name> folder. There are several templates for Leiningen, which affect the...

To refresh the page every five seconds, add this meta element in the head element: <meta http-equiv="refresh" content="5"> CAUTION! While this is a valid command, it is recommended that you do not use it because of its negative effects on user experience. Refreshing the...

This error appears while trying to update or delete records without including the WHERE clause that uses the KEY column. To execute the delete or update anyway - type: SET SQL_SAFE_UPDATES = 0; To enable the safe mode again - type: SET SQL_SAFE_UPDATES = 1;

Agents can be added to a JVM at runtime. To load an agent you will need to use the Attach API's VirtualMachine.attatch(String id). You can then load a compiled agent jar with the following method: public static void loadAgent(String agentPath) { String vmName = ManagementFactory.getRuntimeMXBe...

// This example creates a macro `set!` that functions similarly to the built-in // macro vec! use std::collections::HashSet; macro_rules! set { ( $( $x:expr ),* ) => { // Match zero or more comma delimited items { let mut temp_set = HashSet::new(); // Create a ...

If you are running Docker on OS X or Windows, docker-compose should be included in your Docker for Windows or Docker Toolbox installation. On Linux you can get the latest binaries straight from the GitHub release page: https://github.com/docker/compose/releases You can install the specific releas...

Create a .gitattributes file in the project root containing: * -text This is equivalent to setting core.autocrlf = false.

Create a .gitattributes file in the project root containing: * text=auto This will result in all text files (as identified by Git) being committed with LF, but checked out according to the host operating system default. This is equivalent to the recommended core.autocrlf defaults of: input o...

Props are used to transfer data from parent to child component. Props are read only. Child component can only get the props passed from parent using this.props.keyName. Using props one can make his component reusable.

Generally speaking, empty commits (or commits with state that is identical to the parent) is an error. However, when testing build hooks, CI systems, and other systems that trigger off a commit, it's handy to be able to easily create commits without having to edit/touch a dummy file. The --allow-e...

This is a type system extension that allows types that are existentially quantified, or, in other words, have type variables that only get instantiated at runtime†. A value of existential type is similar to an abstract-base-class reference in OO languages: you don't know the exact type in contains,...

Database transactions ensure that a set of data changes will only be made permanent if every statement is successful. Any query or code failure during a transaction can be caught and you then have the option to roll back the attempted changes. PDO provides simple methods for beginning, committing,...

In this example, documentation for the local function baz (defined in foo.m) can be accessed either by the resulting link in help foo, or directly through help foo>baz. function bar = foo %This is documentation for FOO. % See also foo>baz % This wont be printed, because there is a line w...

On OS X and MacOS, Elixir can be installed via the common package managers: Homebrew $ brew update $ brew install elixir Macports $ sudo port install elixir

The following will create dist/output.jar from the source code in src and the libraries in lib, and will use src/Main.java as the main class. <project name="Project" default="main" basedir="."> <property name="src.dir" value="src&quot...

If you want to use the latest code, you can install it from the repository. While you potentially get new features and fixes, only numbered releases are officially supported. pip install https://github.com/pallets/flask/tarball/master

If you want to develop and contribute to the Flask project, clone the repository and install the code in development mode. git clone ssh://github.com/pallets/flask cd flask python3 -m venv env source env/bin/activate pip install -e . There are some extra dependencies and tools to be aware ...

One of the very basic animations that you could come across is the NumberAnimation. This animation works by changing the numeric value of a property of an item from an initial state to a final state. Consider the following complete example: import QtQuick 2.7 import QtQuick.Controls 2.0 ...

Django's default authentication works on username and password fields. Email authentication backend will authenticate users based on email and password. from django.contrib.auth import get_user_model class EmailBackend(object): """ Custom Email Backend to perform authent...

iex(1)> h List.last def last(list) Returns the last element in list or nil if list is empty. Examples ┃ iex> List.last([]) ┃ nil ┃ ┃ iex> List.last([1]) ┃ 1 ┃ ┃ iex> List.last([1, 2, 3]) ┃ 3