JADE is an object-oriented software development and application platform product from Jade Software Corporation based in New Zealand, first released in 1996. It consists of JADE programming language, IDE and debugger, integrated application server and object database management system.
Designed as a tip-to-edge development environment to allow the system to be encoded in one language from the database server down to the client, it also provides APIs for other languages, including.NET Framework, Java, C/C, and Web services.
Although free limited licenses are available for development, using the JADE platform requires a per-process cost to be paid.
Video JADE (programming language)
Languages ​​
Syntactically, JADE is very similar to Pascal; the syntax is based on the Modula-2 language, which comes from Pascal. While it includes less innovation in Pascal or Modula-2, it lacks certain features of other modern object-oriented languages ​​such as C # and Java.
JADE can import and run the 4GL LINC program and initially its main role.
Programming Model
Like all other popular programming languages ​​used to create database-based software, JADE is entirely object-oriented. JADE is designed to have all the most important features of object-oriented programming, but it does not support overloading methods or operators, and has no parameterised constructor.
The classes in JADE remain together in the scheme. Schemes serve the same purpose as Java packages or namespaces in.NET, but have a hierarchy, and inherit a class from superschemas. This becomes especially useful when programming uses a model-view-controller methodology, as a model class can be inserted into a single schema, then the controller and display class can be built on the model class in the subschema.
Program structure
The JADE program is developed using a user interface that allows programmers to create classes visually and define their properties and methods. Instead of searching for methods in large files, programmers choose the methods they want to edit and only the code for the particular method is displayed. Also instead of compiling all the program code at once, in JADE, each method is compiled individually as soon as the method completes, which means the code can be checked immediately.
All code for JADE application is stored in object oriented database. This allows for multi-user development as the database maintains concurrency control, and with each piece of code being a separate object in the database, it is often possible to recode the system while it is live and online as long as part of the system is being changed unused. Good. That's great for a program at once, in JADE, each method is compiled individually as soon as this method is myanmar. Myanmar is a programmer.
Maps JADE (programming language)
Features
The main purpose of JADE is to create an integrated programming language that allows developers to create one application that will run from end to end instead of having to write three separate applications for database servers, application servers and presentation clients and then write code for them communicating with each other other.
Database object
The most striking difference between JADE and other object-oriented programming languages ​​is that the object database is the original part of the language. For example, when creating objects in JADE, they can be created as temporary or persistent. Creating objects as transients is similar to creating objects in other object-oriented programming languages ​​- objects are only created in memory, and then disappear when the program ends. On the other hand, when an object is created as persistent , when the program ends, the object will remain and be there when the program is run. So when a persistent object JADE automatically works in the background to store and retrieve objects in the database when needed. Objects that can continuously be distributed across multiple co-operation servers, with JADE automatically handling object cache and cache coherence.
There is very little difference between manipulating temporary and persistent objects so JADE makes it appear to the programmer as if all objects in the entire database are in local memory. Most of the time, JADE object-oriented databases are used in multi-user systems, and JADE makes it seem to the programmer as if all objects in the database are stored in shared memory that all users connected to the system can access, even from different computers.
With all the centralized program code on the database server as well as the data, all client nodes can be programmed as if they were running on the database server.
The JADE database is inherently object oriented, and ACID-compliant, and has all the standard features such as atomic transactions, locking, rollback, damage recovery and the ability to store one or more secondary database servers that are synchronized with the primary database for backup, disaster recovery and performance reasons.
To interoperate with relational databases for reporting, business intelligence, and data storage purposes, JADE has since 2010 provided the "Relational Population Service" which allows automatic replication of objects from their original object-oriented databases to one or more relational databases. This feature supports Microsoft SQL Server versions 2000, 2005, and 2008.
Three-tier model
Data-driven software often uses a three-tier methodology with applications divided into three levels - data storage, processing and presentation. In data storage and processing levels, the JADE system is a collection of cooperating servers, called nodes, and multiple nodes can be involved at every level. Each type of node has a different name and everything is able to manipulate objects and execute business logic. Node sets can be used on one or more machines. The database server handles data storage and can also run business logic, while the application server handles processing. In a three-tier model, the presentation client provides the user interface. JADE also provides a two-tier client that combines the capabilities of application servers and presentation clients. Traditionally, these three levels will be created by combining three programs and asking them to communicate to form a system. Having separate different programs like these has many advantages, the main thing is that the system becomes scalable, that is, increasing the power of the system involves simply adding more nodes.
Designing such a system gives programmers the decision to consider whenever they want the code in a particular function. They need to decide whether the function will run best on the database server, application server or client presentation before they start the encoding because it will be difficult to change that decision once the function is encoded to one of the levels.
This is different for JADE applications, because they are encoded as one application from end to end. When creating JADE applications, programmers can think as if they are creating programs that will run on the database server - as if all the data storage, processing and presentation happens on a single computer. When the program runs on three levels, JADE automatically knows to run all code by default on the application server, and to send database requests to the database server and user interface information to the presentation client. However, it is very easy for the programmer to change the location where a particular method is executed and move it to a different level by changing the method signature. Because of this, decisions about where specific code snippets should be executed can be made late in the development cycle, and refactoring code to run on different parts of the system eventually becomes much easier because of the way JADE allows end-to end software development.
Client type
The programmer has the facility to allow three different types of clients to connect to the JADE system. These three types of clients are named:
- JADE Forms
- HTML document
- Web Services
In the same scheme, JADE developers can create many separate applications that can provide multiple interfaces to access the same database.
JADE Forms
The JADE Form application consists of forms, as the name implies. The client must connect via JADE Smart thin client or Standard Client to be able to run applications using JADE Forms.
Smart Thin clients work by connecting to an Application Server that generally performs all processes on behalf of the Smart Thin Client, which means the thin client only needs to be responsible for displaying forms and taking input. This means that a computer running a thin client does not have to be a very powerful computer, and does not require a fast network connection because it does not load data from the database - JADE thin clients are often run through dial-up connections. This is the reason why they are called thin clients, because there is no heavy requirement on the computing power to run these clients.
Standard Client is a Thin Smart Client combined with Application Server on one machine. In this case, the node that runs the client does all the processing and presentation. Standard clients have greater demands on computing power than thin clients, because they have to load data from the database as well as do their own processing.
Benefits of using JADE Forms include:
- Of the three client types, the JADE Form provides the shortest JADE application development time.
- Allows developers to use the same technology from end to end.
- A smart thin client can be packaged so that it can be installed and run on a client computer in a few clicks.
The disadvantages are:
- Unable to reach audiences worldwide as is possible on the World Wide Web.
The JADE form has a twist that appeals to them. It is actually possible to run the JADE Forms application via a web browser by changing its mode to web-enabled . When this happens, JADE automatically generates HTML code to create pages that resemble shapes and controls, with no modifications to the code. This is a very quick way for incompetent programmers with HTML and other web technologies to deliver programs over the web.
HTML document
JADE supports the deployment of applications to the web through its HTML document features. This works very similar to ASP.NET, where the developers create HTML page templates and leave a section in the template for the program to be filled.
The advantages of using HTML documents are:
- Allow apps to reach audiences worldwide.
The disadvantages are:
- When a JADE application uses an HTML document, they no longer use the same technology from end to end. Checking on the front end of the system can be done through JavaScript for example.
- Disabling some processing for the front-end client is no longer as easy or safe.
Web service
Web services are used to allow programs to communicate with each other from remote locations in object-oriented form. Web services can not be accessed directly by human users. One use of Web services with JADE is to allow other technologies such as.NET or Java to use JADE as an object-oriented backend database. The web service also allows the JADE system to interoperate with services provided by other non-JADE systems.
Interoperability
In addition to Web services, JADE is also able to interact with other programs through the language API (including.NET, Java, C/C), call DLLs, ActiveX/COM objects, and.NET assemblies. This allows other programs to access objects and execute methods, and can be used to provide different interfaces for JADE applications. JADE 6.2 provides Java API,.NET Assembly integration, and the ability to run Smart Thin Clients on Windows Mobile devices. JADE 6.3 provides API for.NET languages.
Multilingual capabilities
JADE natively supports multilingual programs. This is done in several ways:
- Strings can be marked as translated , which means they will change depending on the current language.
- Many versions of the same form can be created to suit each language. This means the interface can look very different from one language to another.
- Developers have methods available to access the current locale of the system and so they can implement their own language dependent features.
JADE will automatically switch to the language detected on the system if the language is provided by the developer.
Portability
Currently JADE applications can only run on Windows, Linux support has been dropped. JADE 6.2 enables Smart Thin Clients and Custom Standard Client to run on Windows Mobile devices.
Sample code
In this section there are some short examples of JADE code.
Hello World!
This is "Hello World!" code in JADE:
helloWorld (); start    app .msgBox ( "Hello, World!" , "Hello, World!" , MsgBox_OK_Only MsgBox_Information_Icon ); end ;
or
helloWorld (); start    write "Hello, World!" ; end ;
History
JADE was originally conceived by Sir Gilbert Simpson and is currently developed by Jade Software Corporation.
The first version of JADE is JADE 3, released September 1996.
The current version is JADE 2016, released December 2016, replacing Jade 7.1
See also
- Database management system
- Object-oriented programming
- Database object
References
External links
- Official website
- Examples and Tutorials for JADE Programmers
- JADE 6.1 sends data replication to Microsoft SQL Server
Source of the article : Wikipedia
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