LaxarJS Glossary

While reading LaxarJS manuals and API documentation you will from time to time stumble over terms, that have a certain meaning within the context of LaxarJS. To prevent from defining these terms over and over again, this document is a collection of all terms and our definition. If you deem something important is missing here, feel free to contact us.


In the context of LaxarJS Patterns, an event expressing user intent.

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An artifact in a LaxarJS application, implementing business logic or providing supporting service functionality. Similar to a widget, but without any user interface.

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LaxarJS distinguishes the following application artifacts:

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Secondary resources (HTML, CSS, images) that may belong to certain application artifacts (widgets, controls, layouts).

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Attribute Path

An attribute path is a JavaScript string that references a property in an object or array, possibly deeply nested. It consists of a list of keys denoting the path to follow within the object hierarchy. The keys are written as a string, where each key is separated by a dot from each other.


Consider the following object:

   "items": [
      { "user": { "name": "Tom" } },
      { "user": { "name": "Pete" } }

When evaluated against this object, the attribute path "" would yield the string "Pete".

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Bootstrap CSS

The CSS framework used by default for LaxarJS applications, widgets and controls. Not to be confused with the .bootstrap()-method used to initialize a LaxarJS Bootstrapping Instance.

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Bootstrapping Instance

A runtime context within which LaxarJS instantiates and configures a flow, pages and widgets. Multiple bootstrapping instances may run within the same browser window at the same time in complete isolation from each other. Each instance may use a flow that displays one page at a time. Not to be confused Bootstrap CSS.

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Generally, a basic UI building block to be used within widgets. More specifically, a LaxarJS artifact consisting of a JavaScript module (possibly loading an HTML template) and an optional CSS stylesheet, which may be themed.

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Advanced concept: A partial page definition that can be instantiated from within other pages. Supports feature configuration, similar to widgets.

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Apart from the page and flow definitions, LaxarJS supports application-level configuration which is passed directly to each bootstrapping instance. Use this for deployment-dependent configuration, such as service URLs.

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JSON file containing meta information about a LaxarJS artifact, most importantly its canonical name. A descriptor is required for the following artifact types:

  • Widgets/Activities: widget.json, see also: Widget Descriptor
  • Layouts: layout.json
  • Themes: theme.json
  • Controls: control.json

The name field is used to resolve the implementation module (only for widgets and controls), and to determine the default location for CSS and HTML assets. The styleSource and templateSource attributes of the descriptor can be used to specify non-default stylesheet (such as SCSS) or template (e.g. pug) assets.

Event Bus

Central event broker within each LaxarJS application. Connects widgets and activities through publish/subscribe events.

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Feature Path

Most commonly used as function argument called featurePath

This is an attribute path for a widget feature. If not said otherwise, the path starts after the features key. You'll find this being used very frequently when working with the LaxarJS Patterns library.


In the context of LaxarJS Patterns, a publish/subscribe event announcing a Boolean state to collaborators. Often used to toggle visibility of context-dependent UI items, or to enable/disable form elements.

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Routing configuration for a LaxarJS application. Associates URL patterns with pages, and defines their parameters.

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Internationalization: LaxarJS allows to broadcast changes to application locales and offers a small set of helpers for selecting the correct localization from internationalized values.

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I18n Object

For internationalization purposes, many LaxarJS libraries, widgets and controls support so-called i18n objects instead of primitive values, in order to support multiple localizations. An i18n object is a map from language tag (en-US, de, etc.) to plain text or HTML markup. Depending on the selected locale and resulting language tag, the correct message localization is used.

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Integration Technology

A string that identifies which UI technology a widget or control is built upon. LaxarJS comes with support for a single integration technology, "plain", meaning that an artifact is built using vanilla HTML5/CSS/JavaScript. For any other technology, an appropriate technology adapter must be passed to LaxarJS when bootstrapping the application. The LaxarJS project provides adapters for the following integration technologies: "angular" (for AngularJS v1), "angular2" (for Angular 2 and beyond), "react" (for React) and "vue" (for Vue.js v2).

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Integration Technology Adapter

A JavaScript module that allows LaxarJS to load widgets and controls written in a specific integration technology. Must be passed to LaxarJS when bootstrapping an application.

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Integration Type

A string used in the widget descriptor to distinguish widgets (integration type "widget") from activities (integration type "activity").

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A piece of plain old HTML used to render scaffolding HTML, or to arrange widgets contained in page by including one or more widget areas.

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LaxarJS Patterns

A library helping to support several standard event patterns for widget collaboration, most importantly actions, resources, and flags.

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LaxarJS Mocks

A library that helps to write specification tests (spec tests) for widgets and activities.

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LaxarJS UiKit

A library containing the LaxarJS default theme (a slightly extended Bootstrap 3, plus Font Awesome) as well as JavaScript helper functions for locale-aware parsing and formatting of numbers and dates.

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Standard event sequence that is published by the LaxarJS runtime from the instant a page is entered...

  • beginLifecycleRequest
  • didNavigate

...until it is replaced by the next page:

  • navigateRequest
  • endLifecycleRequest.

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Fragment of an event name when split by . (dot). More specifically, the "middle" part of pattern event names (actions, resources, flags) that is used within page definitions in order to connect collaborating widgets. Also called topic ID in this context.


Configuration for a set of LaxarJS widgets, activities and possibly nested compositions that are run at the same time. Also contains a reference to a main layout, and possibly to additional nested layouts, in order to visually arrange the widgets.


An entry in a flow definition. Binds one or more URL patterns to either a page, or to a redirect.


Architectural pattern used for communication of components within LaxarJS applications.


In the context of LaxarJS Patterns, a publish/subscribe event broadcasting application state to collaborators.

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A named collection of CSS styles that define the look and feel of a LaxarJS application. By default, LaxarJS applications use the default.theme which is just Bootstrap 3 plus Font Awesome. Custom themes can modify the Bootstrap styling or completely replace it, e.g. by using Material Design. Widgets should always define styles for the default.theme.

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Main building block within a LaxarJS application. Provides and-user functionality within its area of the screen.

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Widget Adapter

See Integration Technology Adapter.

Widget Area

An anchor for nested widgets that is provided by layouts and sometimes by widgets. Each widget area is attached to a DOM node and its contents are determined by the page configuration. Widget areas even allow nesting widgets that were created in different integration technologies.

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Widget Descriptor

The contents of a JSON file (called widget.json) containing meta information about a widget. The descriptor defines the name, integration type and technology, and the widget features that may be configured. It may also specify a styleSource and/or templateSource if the widget deviates from the defaults, e.g. when using SCSS.

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Widget Directory

File system directory containing a widget with its descriptor, implementation module, and assets.

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Widget Features

When a widget is instantiated within a page, runtime configuration is passed to the widget controller through the axFeatures injection. The widget descriptor may specify and document what feature configuration is allowed by providing a JSON schema under its features property.

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Widget Instance

Each widget is a blueprint that can be instantiated on any number of pages, or even multiple times within a single page. Each of those instances has its own configuration, its own ID, and its own container node in the browser DOM.

Widget Services, Widget Injections

To use service APIs provided by LaxarJS, most importantly the event bus, widgets and activities request them to be injected into their controller. The specific syntax for this depends on the integration technology. LaxarJS does not use a fancy dependency injection (DI) framework for this, just a simple registry of known services. However, technology adapters may hook into the DI of their respective framework to enrich it with the LaxarJS services.

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Yeoman, Yeoman Generator

Yeoman is a general purpose scaffolding tool that allows to create new software artifacts based on a template, and interactive dialogues to fill in the blanks. The Yeoman Generator for LaxarJS is a plugin for Yeoman that helps to create LaxarJS applications, widgets, activities and controls.