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. These archives are created with a ".zip" extension and can be used to save disk space or transfer files via mediums which may have size limitations (e.g., email or network).
- You create a 4D ZIP archive with the ZIP Create archive command.
- 4D
ZIPFile
andZIPFolder
instances are available through theroot
property (ZIPFolder
) of the object returned by ZIP Read archive command.
Example
To retrieve and view the contents of a ZIP file object:
var $path; $archive : 4D.File
var $zipFile : 4D.ZipFile
var $zipFolder : 4D.ZipFolder
var $txt : Text
$path:=Folder(fk desktop folder).file("MyDocs/Archive.zip")
$archive:=ZIP Read archive($path)
$zipFolder:=$archive.root // store the zip main folder
$zipFile:=$zipFolder.files()[0] //read the first zipped file
If($zipFile.extension=".txt")
$txt:=$zipFile.getText()
End if
Summary
.root : 4D.ZipFolder a virtual folder providing access to the contents of the ZIP archive |
ZIP Create archive
History
Release | Changes |
---|---|
18 | Added |
ZIP Create archive ( fileToZip : 4D.File ; destinationFile : 4D.File ) : Object
ZIP Create archive ( folderToZip : 4D.Folder ; destinationFile : 4D.File { ; options : Integer }) : Object
ZIP Create archive ( zipStructure : Object ; destinationFile : 4D.File ) : Object
Parameter | Type | Description | |
---|---|---|---|
fileToZip | 4D.File | -> | File or Folder object to compress |
folderToZip | 4D.Folder | -> | File or Folder object to compress |
zipStructure | Object | -> | File or Folder object to compress |
destinationFile | 4D.File | -> | Destination file for the archive |
options | Integer | -> | folderToZip option: ZIP Without enclosing folder |
Result | Object | <- | Status object |
Description
The ZIP Create archive
command creates a compressed ZIP archive object and returns the status of the operation.
You can pass a 4D.File, a 4D.Folder, or a zip structure object as first parameter:
-
fileToZip: You simply pass a
4D.File
to compress. -
folderToZip: You pass a
4D.Folder
to compress. In this case, the options parameter allows you to compress only the contents of the folder (i.e., exclude the enclosing folder). By default,ZIP Create archive
will compress the folder and its contents, so that the decompressing operation will recreate a folder. If you want the decompressing operation to restore only the contents of the folder, pass theZIP Without enclosing folder
constant in the options parameter. -
zipStructure: You pass an object describing the ZIP archive object. The following properties are available to define the structure:
Property | Type | Description | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
compression | Integer | ZIP Compression standard : Deflate compression (default)ZIP Compression LZMA : LZMA compressionZIP Compression XZ : XZ compressionZIP Compression none : No compression | ||||||||||||
level | Integer | Compression level. Possible values: 1 to 10. A lower value will produce a larger file, while a higher value will produce a smaller file. Compression level has however an impact on performance. Default values if omitted: ZIP Compression standard : 6ZIP Compression LZMA : 4ZIP Compression XZ : 4 | ||||||||||||
encryption | Integer | The encryption to use if a password is set:ZIP Encryption AES128 : AES encryption using 128-bit key.ZIP Encryption AES192 : AES encryption using 192-bit key.ZIP Encryption AES256 : AES encryption using 256-bit key (default if password is set).ZIP Encryption none : Data is not encrypted (default if no password is set) | ||||||||||||
password | Text | A password to use if encryption is required. | ||||||||||||
files | Collection | 4D.File or 4D.Folder objects or
| ||||||||||||
callback | 4D.Function | A callback formula that will receive the compression progress (0 - 100) in $1. |
In the destinationFile parameter, pass a 4D.File
object describing the ZIP archive to create (name, location, etc.). It is advised to use the ".zip" extension if you want the ZIP archive to be processed automatically by any software.
Once an archive is created, you can use the ZIP Read archive command to access it.
Status object
The returned status object contains the following properties:
Property | Type | Description |
---|---|---|
statusText | Text | Error message (if any): |
status | Integer | Status code |
success | Boolean | True if archive created successfully, else false |
Example 1
To compress a 4D.File
:
var $file; $destination : 4D.File
var $status : Object
$destination:=Folder(fk desktop folder).file("MyDocs/file.zip")
$file:=Folder(fk desktop folder).file("MyDocs/text.txt")
$status:=ZIP Create archive($file;$destination)
Example 2
To compress a 4D.Folder
without the folder itself:
var $folder : 4D.Folder
var $destination : 4D.File
var $status : Object
$destination:=Folder(fk desktop folder).file("MyDocs/Images.zip")
$folder:=Folder(fk desktop folder).folder("MyDocs/Images")
$status:=ZIP Create archive($folder;$destination;ZIP Without enclosing folder)
Example 3
To compress a ZIP archive structure with a password and progress bar:
var $destination : 4D.File
var $zip;$status : Object
var progID : Integer
$destination:=Folder(fk desktop folder).file("MyDocs/Archive.zip")
$zip:=New object
$zip.files:=Folder(fk desktop folder).folder("MyDocs/Resources").folders()
$zip.password:="password"
$zip.callback:=Formula(myFormulaCompressingMethod($1))
progID:=Progress New //we use the 4D Progress component
$status:=ZIP Create archive($zip;$destination)
Progress QUIT(progID)
myFormulaCompressingMethod
:
var $1 : Integer
Progress SET PROGRESS(progID;Num($1/100))
Example 4
You want to pass a collection of folders and files to compress to the zipStructure object:
var $destination : 4D.File
var $zip;$err : Object
$zip:=New object
$zip.files:=New collection
$zip.files.push(New object("source";Folder(fk desktop folder).file("Tests/text.txt")))
$zip.files.push(New object("source";Folder(fk desktop folder).file("Tests/text2.txt")))
$zip.files.push(New object("source";Folder(fk desktop folder).file("Images/image.png")))
$destination:=Folder(fk desktop folder).file("file.zip")
$err:=ZIP Create archive($zip;$destination)
ZIP Read archive
History
Release | Changes |
---|---|
18 | Added |
ZIP Read archive ( zipFile : 4D.File { ; password : Text }) : 4D.ZipArchive
Parameter | Type | Description | |
---|---|---|---|
zipFile | 4D.File | -> | Zip archive file |
password | Text | -> | ZIP archive password if any |
Result | 4D.ZipArchive | <- | Archive object |
Description
The ZIP Read archive
command retrieves the contents of zipFile and returns it as a 4D.ZipArchive
object.
This command does not uncompress the ZIP archive, it only provides a view of its contents. To extract the contents of an archive, you need to use methods such as file.copyTo() or folder.copyTo().
Pass a 4D.File
object referencing the compressed ZIP archive in the zipFile parameter. The target archive file will be opened until the ZIP Read archive
has finished executing and all contents/references have been extracted/released, then it will be closed automatically.
If the zipFile is password protected, you need to use the optional password parameter to provide a password. If a password is required but not passed when trying to read the contents of the archive, an error is generated.
Archive object
The returned 4D.ZipArchive
object contains a single root
property whose value is a 4D.ZipFolder
object. This folder describes the whole contents of the ZIP archive.
Example
To retrieve and view the contents of a ZIP file object:
var $archive : 4D.ZipArchive
var $path : 4D.File
$path:=Folder(fk desktop folder).file("MyDocs/Archive.zip")
$archive:=ZIP Read archive($path)
To retrieve the list of the files and folders in the archive:
$folders:=$archive.root.folders()
$files:=$archive.root.files()
To read the contents of a file without extracting it from the root folder:
If($files[$i].extension=".txt")
$txt:=$files[$i].getText()
Else
$blob:=$files[$i].getContent()
End if
To extract from the root folder:
//extract a file
$folderResult:=$files[$i].copyTo(Folder(fk desktop folder).folder("MyDocs"))
//extract all files
$folderResult:=$archive.root.copyTo(Folder(fk desktop folder).folder("MyDocs"))
.root
.root : 4D.ZipFolder
Description
The .root
property contains a virtual folder providing access to the contents of the ZIP archive.
The root
folder and its contents can be manipulated with the ZipFile and ZipFolder functions and properties.
This property is read-only.