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What is Core Component Technical Specification CCTS

Hong Lam July 9,2021

To access references using constructor injection, constructor parameters are annotated with Reference. A ComponentInstance encapsulates a component instance of an activated component configuration. ComponentInstances are created whenever a component configuration is activated.

ExportedService – Component Property Type for the remote service properties for an exported service. ReferenceDTO – A representation of a declared reference to a service. Returns the ComponentDescriptionDTO declared with the specified name by the specified bundle. This is used to distinguish the default value for an element and should not otherwise be used. Component.reference() element – There is no parameter number. If specified and this reference annotates a field, the specified name must match the name of the annotated field.

OCM (Open Container Model)

ServiceDescription – Component Property Type for the service.description service property. The zero-based parameter number of the constructor parameter for the reference. This is declared in the class attribute of the implementation element. True if the specified component description is currently enabled. Returns whether the specified component description is currently enabled.

This name is local to the component and can be used to locate a bound service of this reference with one of the locateService methods of ComponentContext. Each reference element within the component must have a unique name. The default value of this attribute is the value of the interfaceattribute of this element. If multiple referenceelements in the component use the same interface name, then using the default value for this attribute will result in duplicate reference names.

IllegalArgumentException– If the specified service object was not provided by this ComponentServiceObjects object. A service object previously provided by this ComponentServiceObjects object. The bundle’s wiring has no required wire for an osgi.extender capability with the name osgi.component. The bundle’s wiring has a required wire for at least one osgi.extender capability with the name osgi.component and the first of these required wires is wired to SCR.

Unbind – The unbind method, if specified, is called when SCR needs to unbind the service. The elements in the component’s description are defined in Component Description. The XML grammar for the component declaration is defined by the XML Schema, see Component Description Schema. In simple words Plugins are foreign entities and their origin is not from the browser.

2 Components

In such a context, it is unreasonable to expect that most code created by end users will be callable in a black box manner through interfaces. Instead, end users will need alternate approaches for reusing one another’s code. The Reference annotation is updated to allow the field-collection-type to be set if the desired type cannot be properly inferred by the annotation processing tool. This is declared in the interface attribute of the reference element. This is declared in the immediate attribute of the component element.

• When used on a constructor, the constructor will be used to construct the component instances.
• If there is an updated method name, the component must contain a method with that name.
• From a programmer’s point of view the service component model provides a simplified programming model.
• The value of this attribute is used for the value of the target property of the reference.
• This reference field option can only be used for a dynamic reference with multiple cardinality.

An application event may access a data object and may be composed of other application events. The name of an application event should preferably be a verb definition of component specification in the perfect tense; e.g., “claim received”. An application event may have a time attribute that denotes the moment or moments at which the event happens.

Origin of Web Component

SCR must register a service after the component configuration becomes satisfied. The registration of this service must look to observers of the service registry as if the component’s bundle actually registered this service. This makes it possible to register services without creating a class loader for the bundle and loading classes, thereby allowing reduction in initialization time and a delay in memory footprint. The enabled state of a component can be controlled with the Component Context enableComponent and disableComponent methods. The purpose of later enabling a component is to be able to decide programmatically when a component can become enabled. For example, an immediate component can perform some initialization work before other components in the bundle are enabled.

For Character types, the conversion must be handled by Integer.valueOf method, a Character is always represented by its Unicode value. A corresponding configuration is a Configuration object where the PID is the name of the component. If enabled is set to false, the component is disabled until the method enableComponent is called on the ComponentContext object.

Application Layer

It has a purpose, which states this utility to the environment. This means, for example, that if this environment includes business processes, application services should have business relevance. An application service represents an explicitly defined exposed application behavior. An application event is an application behavior element that denotes a state change.

The deployer can also set the target property by establishing a configuration for the component which sets the value of the target property. This allows the deployer to override the target property in the component description. This collection can be set by the constructor of the component instance.

Composition involves integrating components with each other and with the component infrastructure. Normally you have to write ‘glue code’ to integrate components. CBSE essentialsIndependent components specified by their interfaces. This repository contains the contract and schema definition for Gardener’s CNUDIE Component model and its revised successor OCM . In addition to those language-independent specifications, it also features bindings for programming languages, relevant to the Gardener ecosystem. Automated behavior that can be performed by an application component.

A reference element has the attributes defined in the following table. The properties element references an entry in the bundle whose contents conform to a standard Java Properties File. The component Component annotation will define the implementation element automatically from the type it is applied to. The Deactivate annotation must be applied to at most one method which is to be used as the deactivate method. Component descriptions are defined in XML documents contained in a bundle and any attached fragments. If the update option is used when not permitted, SCR must log an error message with the Log Service, if present, and the field must not be modified.

5.13 Updated

The field-collection-type attribute of the reference element of a Component Description. Annotated field – The field option is based upon the policy and cardinality of the reference and the modifiers of the field. If the policy is ReferencePolicy.DYNAMIC, the cardinality is 0..n or 1..n, and the field is declared final, the field option is FieldOption.UPDATE. When the annotation is applied to a parameter of a constructor, the parameter will contain the bound service of the reference. The configuration-pid attribute of the component element of a Component Description. The configuration-policy attribute of the component element of a Component Description.

If there is a tie in ranking, the service with the lowest service id (as specified in its Constants.SERVICE_IDproperty); that is, the service that was registered first is returned. The component configuration was deactivated because the bundle was stopped. A component property that contains the generated id for a component configuration. A bundle that contains service components https://globalcloudteam.com/ should require the osgi.extender capability from SCR. This requirement will wire the bundle to the SCR implementation and ensure that SCR is using the same org.osgi.service.component package as the bundle if the bundle uses that package. Component property types for standard service properties are specified in the org.osgi.service.component.propertytypes package.

Fields

The component’s constructor can set the field with its choice of collection implementation. In this case, the field can be declared with the final modifier. The collection implementation used by the component should use identity rather than equals or hashCode to manage the elements of the collection. The collection implementation should also be thread-safe since SCR may update the collection from threads different than those used by the component instance. ComponentServiceObjects – A Component Service Objects for the bound service.

It emerged from the failure of object-oriented development to support effective reuse. Components are more abstract than object classes and can be considered to be stand-alone service providers. An encapsulation of application functionality aligned to implementation structure, which is modular and replaceable. An application interaction describes the collective behavior that is performed by the components that participate in an application collaboration. This may, for example, include the communication pattern between these components.

13 org.osgi.service.component.annotations

If the deactivate attribute is specified and no suitable method is located, SCR must log an error message with the Log Service, if present, and the deactivation of the component configuration will continue. The name of the deactivate method can be specified by the deactivateattribute. If the deactivate attribute is not specified, the default method name of deactivate is used. Activation fields must not be modified during deactivation. SCR must locate a suitable method as specified in Locating Component Methods and Fields. Modify the bound services for the dynamic references if the set of target services changed due to changes in the target properties.

More Definitions of Component Specifications

The enableComponent and disableComponentmethods must return after changing the enabled state of the named component. Any actions that result from this, such as activating or deactivating a component configuration, must occur asynchronously to the method call. In this case name, type, and value parts map to the attributes of the factory-property element. If multiple values must be specified then the same name can be repeated multiple times. The Reference annotation will use the type of the first parameter of the annotated method or the type of the annotated parameter or field to determine the servicevalue. If the type of the property is not String, parsing of the value is done by the static valueOf method in the given type.

This element consists of an array of strings where each string defines an entry. The order within the array is the order that must be used for the XML. However, the annotations do not support interleaving of the generated factory-property and factory-properties elements. At runtime, SCR reads the entry to obtain the factory properties and their values.