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  • Deserialization
  • Change of behavior in version 10: generating a XML serialization for the Mobile devices
  • Speed
  • Serializing the members of classes and structures
  • Serialization name of classes
  • Limits
WINDEV
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WEBDEV
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WINDEV Mobile
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Others
Stored procedures
Transforms the following elements into a specific format:
  • a structure (and its sub-elements).
  • a class (and its sub-elements).
  • an array (including the associative arrays).
  • a queue.
  • a stack.
  • a list.
  • Versions 15 and later
    an advanced type of variable (gglCalendar for example).
    New in version 15
    an advanced type of variable (gglCalendar for example).
    an advanced type of variable (gglCalendar for example).
The available formats are XML, binary and JSON. Then, the initial format can be retrieved by Deserialize.
// This example explains how to use the Serialize/Deserialize functions
// with an Array variable.
// These functions can use all types of WLanguage variables.
 
 
MyArray is array of strings
bufResult is Buffer
 
// Adds elements into the array
Add(MyArray, "WINDEV")
Add(MyArray, "WEBDEV")
Add(MyArray, "WINDEV MOBILE")
 
// Serialize the array in the buffer in JSON
// => Save the array and its entire content in a JSON string
Serialize(MyArray, bufResult, psdJSON)
 
// Deserialize the JSON buffer
// => Rebuild the WLanguage array from the JSON string
MyRebuiltArray is array of strings
Deserialize(MyRebuiltArray, bufResult, psdJSON)
Syntax
Serialize(<Variable> , <Buffer> , <Parameters> [, <Root name>])
<Variable>: Type of variable
Variable to serialize. This variable is a structure, a class, an array, a queue, a list or a stack.
<Buffer>: Ansi character string or buffer
Variable that contains the result of serialization.
<Parameters>: Integer constant
Type of serialization:
psdBinaryBinary serialization.
Versions 17 and later
psdBinaryFormat16
New in version 17
psdBinaryFormat16
psdBinaryFormat16
Binary serialization in 16 compatible format.
This format must be used if an application in version 17 must provide data to an application in version 16 or earlier.
This format must not be used in Unicode mode.
Versions 19 and later
psdJSON
New in version 19
psdJSON
psdJSON
Serialization in JSON format.
The encoding used corresponds to the JSON standard:
  • using an encoding in 7-bit ASCII, which means the first 128 characters, the non-accented characters,
  • using a JSON encoding of other characters: "\u" followed by the character code in hexadecimal on 4. Example: for "é" (ASCII code 233, hexadecimal code E9), the encoding corresponds to "\u00E9".
Versions 22 and later
psdFormatting
New in version 22
psdFormatting
psdFormatting
Serialization in JSON or XML format with carriage return and indent.
The encoding used corresponds to the JSON or XML standard.
Caution: This constant must be combined with the psdJSON or psdXML constant.
psdXMLXML serialization with reference to sub-objects. This type of serialization allows you to use the XML format as storage and exchange modes between applications written in WLanguage.
Versions 20 and later
psdXMLAggregated
New in version 20
psdXMLAggregated
psdXMLAggregated
XML serialization with direct aggregation of sub-objects. The type of serialization allows you to easily generate an XML file in standard format, used to perform exchanges with other systems.
Note: A deserialization in psdXMLAggregated mode is available, however the WLanguage elements (variants, arrays, derived classes, ...) will differ from the source ones.
<Root name>: Character string (with quotes)
Versions 20 and later
Name of the root of the generated XML. This parameter is taken into account in psdXMLAggregated mode only.
If this parameter is not specified, the name of the root is "DOCUMENT".
New in version 20
Name of the root of the generated XML. This parameter is taken into account in psdXMLAggregated mode only.
If this parameter is not specified, the name of the root is "DOCUMENT".
Name of the root of the generated XML. This parameter is taken into account in psdXMLAggregated mode only.
If this parameter is not specified, the name of the root is "DOCUMENT".
Remarks

Deserialization

The deserialization of an array, queue, list or stack deletes the content from this element.
If additional members are found in the structure or in the class:
  • if a structure or a class is deserialized: the additional members keep the value they had before the deserialization.
  • if an array of structure or class is deserialized: the additional members take the default value of the member type.
If additional members are found in the serialized buffer, they are ignored during the deserialization.
To deserialize an untyped dynamic array, this array must be allocated beforehand.
To deserialize a class or a structure containing an untyped dynamic array, this array must be allocated beforehand.
The XML deserialization requires the wdxxxxml.dll or wpxxxxml.dll library.

Change of behavior in version 10: generating a XML serialization for the Mobile devices

Up to version 100050, the use of the psdXML constant did not generate a valid XML file. The generated format caused a problem on the Mobile devices. This problem was fixed.
An XML file created with a version later than version 100050 cannot be read by a program compiled with an earlier version. To keep the operating mode of version 100050, all you have to do is use the psdXML_OldFormat constant.

Speed

The binary serialization is faster than the XML serialization.
Versions 19 and later

Serializing the members of classes and structures

By default, all the members of a class or structure are serialized.
You have the ability to precisely manage the serialization of each member:
  • by specifying the member that will be serialized during the call to Serialize.
    This operation can be performed on all types of serialization (XML, JSON, binary).
  • by changing the member name during the serialization by Serialize.
    This operation can be performed during a binary serialization only.
This management of serialization is performed by using the following syntax:
  • Serialization (or not) of a member :
    <Member name> is <Member type> [, Serialize = <True/False>] [, xmlAttribute]
  • Serialization and change of member name:
    <Member name> is <Member type> [, Serialize = <New name>] [, xmlAttribute]
Versions 20 and later
The "xmlAttribute" extension attribute is used to specify that the member is created as attribute (instead of tag). This attribute is taken into account during a psdXMLAggregated serialization only.
New in version 20
The "xmlAttribute" extension attribute is used to specify that the member is created as attribute (instead of tag). This attribute is taken into account during a psdXMLAggregated serialization only.
The "xmlAttribute" extension attribute is used to specify that the member is created as attribute (instead of tag). This attribute is taken into account during a psdXMLAggregated serialization only.
Example for a class:
Cl is Class
// Serialized member
SerializedMember is int
// Non-serialized member
NonSerializedMember is string, Serialize = False  
// Member renamed during the serialization
RenamedMember is int, Serialize = "NewMemberName"
END
Note: To avoid serializing an array member, use the following syntax:
t is array <Serialize = False> of int
t2 is array <Serialize = "<serialization name>"> of int
New in version 19

Serializing the members of classes and structures

By default, all the members of a class or structure are serialized.
You have the ability to precisely manage the serialization of each member:
  • by specifying the member that will be serialized during the call to Serialize.
    This operation can be performed on all types of serialization (XML, JSON, binary).
  • by changing the member name during the serialization by Serialize.
    This operation can be performed during a binary serialization only.
This management of serialization is performed by using the following syntax:
  • Serialization (or not) of a member :
    <Member name> is <Member type> [, Serialize = <True/False>] [, xmlAttribute]
  • Serialization and change of member name:
    <Member name> is <Member type> [, Serialize = <New name>] [, xmlAttribute]
Versions 20 and later
The "xmlAttribute" extension attribute is used to specify that the member is created as attribute (instead of tag). This attribute is taken into account during a psdXMLAggregated serialization only.
New in version 20
The "xmlAttribute" extension attribute is used to specify that the member is created as attribute (instead of tag). This attribute is taken into account during a psdXMLAggregated serialization only.
The "xmlAttribute" extension attribute is used to specify that the member is created as attribute (instead of tag). This attribute is taken into account during a psdXMLAggregated serialization only.
Example for a class:
Cl is Class
// Serialized member
SerializedMember is int
// Non-serialized member
NonSerializedMember is string, Serialize = False  
// Member renamed during the serialization
RenamedMember is int, Serialize = "NewMemberName"
END
Note: To avoid serializing an array member, use the following syntax:
t is array <Serialize = False> of int
t2 is array <Serialize = "<serialization name>"> of int

Serializing the members of classes and structures

By default, all the members of a class or structure are serialized.
You have the ability to precisely manage the serialization of each member:
  • by specifying the member that will be serialized during the call to Serialize.
    This operation can be performed on all types of serialization (XML, JSON, binary).
  • by changing the member name during the serialization by Serialize.
    This operation can be performed during a binary serialization only.
This management of serialization is performed by using the following syntax:
  • Serialization (or not) of a member :
    <Member name> is <Member type> [, Serialize = <True/False>] [, xmlAttribute]
  • Serialization and change of member name:
    <Member name> is <Member type> [, Serialize = <New name>] [, xmlAttribute]
Versions 20 and later
The "xmlAttribute" extension attribute is used to specify that the member is created as attribute (instead of tag). This attribute is taken into account during a psdXMLAggregated serialization only.
New in version 20
The "xmlAttribute" extension attribute is used to specify that the member is created as attribute (instead of tag). This attribute is taken into account during a psdXMLAggregated serialization only.
The "xmlAttribute" extension attribute is used to specify that the member is created as attribute (instead of tag). This attribute is taken into account during a psdXMLAggregated serialization only.
Example for a class:
Cl is Class
// Serialized member
SerializedMember is int
// Non-serialized member
NonSerializedMember is string, Serialize = False  
// Member renamed during the serialization
RenamedMember is int, Serialize = "NewMemberName"
END
Note: To avoid serializing an array member, use the following syntax:
t is array <Serialize = False> of int
t2 is array <Serialize = "<serialization name>"> of int
Versions 20 and later

Serialization name of classes

The "Serialize" extension attribute is available for the classes in order to specify the serialization name.
The following syntax is used:
<Class name> is Class [, Serialize = <New name>]
New in version 20

Serialization name of classes

The "Serialize" extension attribute is available for the classes in order to specify the serialization name.
The following syntax is used:
<Class name> is Class [, Serialize = <New name>]

Serialization name of classes

The "Serialize" extension attribute is available for the classes in order to specify the serialization name.
The following syntax is used:
<Class name> is Class [, Serialize = <New name>]

Limits

  • The fixed arrays and the associative arrays of local structures cannot be serialized.
  • The global members of classes are not serialized.
  • The XML serialization/deserialization of an array of structures with a string member containing "\0" or Charact(0) returns the following error: "Wrong serialization format". In this case, a binary serialization/deserialization must be performed.
  • You cannot serialize/deserialize an array of classes or structures if this class or structure contains a dynamic array without type. A dynamic array with defined type must be used in this class or in this structure.
  • To serialize/deserialize a class, you must have a constructor with 0 parameter.
  • Versions 20 and later
    Limits in psdXMLAggregated mode: the serialization/deserialization of advanced variables triggers an error at run time. The properties of the advanced variables are not serialized.
    New in version 20
    Limits in psdXMLAggregated mode: the serialization/deserialization of advanced variables triggers an error at run time. The properties of the advanced variables are not serialized.
    Limits in psdXMLAggregated mode: the serialization/deserialization of advanced variables triggers an error at run time. The properties of the advanced variables are not serialized.
  • stacks, queues, lists:
    • The JSON serialization of stacks, queues and lists is not available.
  • Only the JSON serialization is available for the Record variables. No deserialization is possible.
Related Examples:
The Serialize/Deserialize functions Unit examples (WEBDEV): The Serialize/Deserialize functions
[ + ] This example explains how to use the WLanguage functions Serialize and Deserialize.
The serialization consists in saving a variable, an object, a structure, an array or any other element in a buffer. Then, this buffer can be saved on disk or sent by socket. This allows for the persistence of objects.
The Deserialize function is used to rebuild an object, an array or a structure from a buffer.
The Serialize/Deserialize functions Unit examples (WINDEV): The Serialize/Deserialize functions
[ + ] Using the WLanguage Serialize and Deserialize functions
The serialization consists in saving a variable, an object, a structure, an array or any other element in a buffer. Then, this buffer can be saved on disk or sent by socket. This allows for the persistence of objects.
The Deserialize function is used to rebuild an object, an array or a structure from a buffer.
Business / GUI classification : Neutral code
Component : wd250vm.dll
Minimum version required
  • Version 10
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