📄️ Funções e comandos de classe
As funções e propriedades da classe 4D estão disponíveis através de objectos de instância de classe. Esta seção descreve a API da classe 4D incorporada, bem como os comandos de construção associados.
📄️ Blob
The Blob class lets you create and manipulate blob objects (4D.Blob).
📄️ Class
When a user class is defined in the project, it is loaded in the 4D language environment. Uma classe é um objeto em si mesmo, da classe "Class", que tem propriedades e uma função.
📄️ Collection
The Collection class manages Collection type variables.
📄️ CryptoKey
The CryptoKey class in the 4D language encapsulates an asymmetric encryption key pair.
📄️ DataClass
A DataClass provides an object interface to a database table. All dataclasses in a 4D application are available as a property of the ds datastore.
📄️ DataStore
A Datastore is the interface object provided by ORDA to reference and access a database. Datastore objects are returned by the following commands:
📄️ Email
Creating, sending or receiving emails in 4D is done by handling an Email object.
📄️ Entity
An entity is an instance of a Dataclass, like a record of the table matching the dataclass in its associated datastore. Contém os mesmos atributos que o dataclass assim como os valores de dados e propriedades e funções específicas.
📄️ EntitySelection
An entity selection is an object containing one or more reference(s) to entities belonging to the same Dataclass. Uma seleção de entidades pode conter 0, 1 ou X entidades da dataclass -- onde X pode representar o número total de entidades contidas na dataclass.
📄️ File
File objects are created with the File command. Contêm referências a ficheiros de disco que podem ou não existir efectivamente no disco. For example, when you execute the File command to create a new file, a valid File object is created but nothing is actually stored on disk until you call the file.create( ) function.
📄️ FileHandle
The FileHandle class has functions that allow you to sequentially read from or append contents to an opened File object. O manuseamento de um arquivo pode acessar a qualquer parte de um documento.
📄️ Folder
Folder objects are created with the Folder command. Contêm referências a pastas que podem ou não existir efectivamente no disco. For example, when you execute the Folder command to create a new folder, a valid Folder object is created but nothing is actually stored on disk until you call the folder.create() function.
📄️ Function
A 4D.Function object contains a piece of code that can be executed from an object, either using the () operator, or using the apply() and call() functions. 4D proposes three kinds of Function objects:
📄️ HTTPRequest
The HTTPRequest class allows you to handle HTTPRequest objects that can be used to configure and send requests to an HTTP server, as well as to process the HTTP server responses.
📄️ IMAPTransporter
The IMAPTransporter class allows you to retrieve messages from a IMAP email server.
📄️ MailAttachment
Attachment objects allow referencing files within a Email object. Attachment objects are created using the MAIL New attachment command.
📄️ POP3Transporter
The POP3Transporter class allows you to retrieve messages from a POP3 email server.
📄️ Session
Session objects are returned by the Session command. These objects provide the developer with an interface allowing to manage the current user session and execute actions such as store contextual data, share information between session processes, launch session-related preemptive processes, or (web only) manage privileges.
📄️ Signal
Sinais são ferramentas fornecidas pela linguagem 4D para gerenciar interações e evitar conflitos entre processos em uma aplicação multiprocesso. Sinais permitem assegurar que um ou mais processos vão esperar por uma tarefa específica a ser completada antes de continuar a execução. Qualquer processo pode esperar ou liberar um sinal.
📄️ SMTPTransporter
The SMTPTransporter class allows you to configure SMTP connections and send emails through SMTP transporter objects.
📄️ SystemWorker
System workers allow the 4D code to call any external process (a shell command, PHP, etc.) on the same machine. Os trabalhadores do sistema são chamados assíncronos. Ao utilizar os callbacks, 4D torna possível a comunicação de ambas as maneiras.
📄️ WebForm
The WebForm class contains functions and properties allowing to handle your Qodly webform components. This class is detailed in the Qodly documentation.
📄️ WebFormItem
4D.WebFormItem objects are properties of the 4D.WebForm object returned by the Web Form command.
📄️ WebServer
The WebServer class API allows you to start and monitor a web server for the main (host) application as well as each hosted component (see the Web Server object overview). This class is available from the 4D class store.
📄️ WebSocket
The WebSocket class allows you to open a WebSocket client connection with a server, send and receive data, and close the connection.
📄️ WebSocketConnection
The WebSocketConnection class API allows you to handle WebSocket connections, once established using the WebSocketServer class.
📄️ WebSocketServer
A classe WebSocketServer permite-lhe criar e configurar um servidor WebSocket em 4D. Quando o servidor 4D WebSocket estiver ativo, você poderá abrir e usar conexões WebSocket entre o 4D e os clientes usando a classe [WebSocketConnection] (WebSocketConnectionClass.md).
📄️ ZIPArchive
A 4D ZIP archive is a File or Folder object containing one or more files or folders, which are compressed to be smaller than their original size. Esses arquivos são criados com uma extensão ".zip" e podem ser usados para poupar espaço em disco ou transferir arquivos via meios que tenham limitações de tamanho (por exemplo, um email ou por uma rede).
📄️ ZIPFile
The following properties and functions from the File class are available to ZIPFile objects:
📄️ ZIPFolder
The following properties and functions from the Folder class are available to ZIPFolder objects: