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We may use QML to build hybrid applications, since it's much more easier than C++. So we should know how they communicate with each other.

How to validade user inputs. Validation constrains the values a user can input into a cell, and/or set a combobox for the user select the value for the cell. Optionally, a message can be displayed when the user clicks in a cell and a message error, when the validation fails.

AppDelegate is a protocol which defines methods that are called by the singleton UIApplication object in response to important events in the lifetime of an app. Normally used to perform tasks on application startup (setup app environment, analitycs (ex.: Mixpanel/GoogleAnalytics/Crashlitics), DB st...

Strict Mode is a special class introduced in Android 2.3 for debugging. This developer tools detect things done accidentally and bring them to our attention so that we can fix them. It is most commonly used to catch the accidental disk or network access on the applications’ main thread, where UI ope...

In order to use custom tags in JSP,we used to have TLD files,along with a Java class to define the custom tags but post JSP 2.0 specs,the same can be achieved,without the need for any Source code files,making it easy to maintain and it can also be created by someone with basic knowledge of JSP tags ...

Regular non-capturing groups allow the engine to re-enter the group and attempt to match something different (such as a different alternation, or match fewer characters when a quantifier is used). Atomic groups differ from regular non-capturing groups in that backtracking is forbidden. Once the gro...

You can use hierarchical queries to retrieve data based on a natural hierarchical relationship between rows in a table

Example of how to copy existing table structure with/without data CREATE TABLE schemaName.table AS (SELECT columns FROM schemaName.table) WITH DATA

This topic is going to focus on the A* Pathfinding algorithm, how it's used, and why it works. Note to future contributors: I have added an example for A* Pathfinding without any obstacles, on a 4x4 grid. An example with obstacles is still needed.

Sometimes we need to share some component between some apps and publishing it in npm is one of the best ways of doing this. There are some tricks that we need to know to be able to use a normal component as npm package without changing the structure as inlining external styles. You can see a minim...

A field formatter specifies the way a field is rendered in Drupal templates. The formatter used by each field can be configured in the Manage display tab associated with the entity type that you are configuring. Fields can have different formatters depending on the view mode that is being displayed...

Internationalization (i18n) and Localization (L10n) are used to adapt software according to differences in languages, regional differences and target audience. Internationalization : the process of planning for future localization i.e. making the software design flexible to an extent that it can ad...

The goal of this topic is to document best practices when asking Apache Spark related questions.

This section provides an overview of what floating-point is, and why a developer might want to use it. It should also mention any large subjects within floating-point, and link out to the related topics. Since the Documentation for floating-point is new, you may need to create initial versions ...

The branching operation of sed can help control the flow of the program.

The fit command can fit a user-defined function to a set of data points (x,y) or (x,y,z), using an implementation of the nonlinear least-squares (NLLS) Marquardt-Levenberg algorithm. Any user-defined variable occurring in the function body may serve as a fit parameter, but the return type of the fu...

Creating a class in Pharo is as simple as sending subclass: message to another class object. But most of the classes are created and modified in a system browser (currently Nautilus).