OB GET PROPERTY NAMES

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4D v20.6


OB GET PROPERTY NAMES ( object ; arrProperties {; arrTypes} )

Parameter	Type	Description
object	Object	Structured object
arrProperties	Text array	Property names
arrTypes	Longint array	Property types

Description

The OB GET PROPERTY NAMES command returns, in arrProperties, the names of the properties contained in the language object designated by the object parameter.

object must have been defined using the C_OBJECT command or designate a 4D object field.

Pass a text array in the arrProperties parameter. If the array does not exist, the command creates and sizes it automatically.

Optionally, you can also pass a longint array in arrTypes. For each element of arrProperties, the command returns, in arrTypes, the type of value stored in the property. You can compare the values received with the following constants, found in the "Field and Variable Types" theme:

Constant	Type	Value
Is Boolean	Longint	6
Is collection	Longint	42
Is null	Longint	255
Is object	Longint	38
Is real	Longint	1
Is text	Longint	2
Object array	Longint	39

Note: For array attributes, the command returns Is collection.

Example 1

You want to test that an object is not empty:

 ARRAY TEXT(arrNames;0)

 ARRAY LONGINT(arrTypes;0)

 C_OBJECT($ref_richard)

 OB SET($ref_richard;"name";"Richard";"age";7)

 OB GET PROPERTY NAMES($ref_richard;arrNames;arrTypes)

  // arrNames{1}="name", arrNames{2}="age"

  // arrTypes{1}=2, arrTypes{2}=1

 If(Size of array(arrNames)#0)

  // ...

 End if

Example 2

Using an object array element:

 C_OBJECT($Children;$ref_richard;$ref_susan;$ref_james)

 ARRAY OBJECT($arrayChildren;0)

 

 OB SET($ref_richard;"name";"Richard";"age";7)

 APPEND TO ARRAY($arrayChildren;$ref_richard)

 OB SET($ref_susan;"name";"Susan";"age";4;"girl";True) //additional attribute

 APPEND TO ARRAY($arrayChildren;$ref_susan)

 OB SET($ref_james;"name";"James")

 OB SET NULL($ref_james;"age") //null attribute

 APPEND TO ARRAY($arrayChildren;$ref_james)

 

 OB GET PROPERTY NAMES($arrayChildren{1};$arrNames;$arrTypes)

  // $arrayChildren{1} = {"name":"Richard","age":7}

  // $arrNames{1}="name"

  // $arrNames{2}="age"

  // $arrTypes{1}=2

  // $arrTypes{2}=1

 

 OB GET PROPERTY NAMES($arrayChildren{2};$arrNames;$arrTypes)

  // $arrayChildren{3} = {"name":"Susan","age":4,"girl":true}

  // $arrNames{1}="name"

  // $arrNames{2}="age"

  // $arrNames{3}="girl"

  // $arrTypes{1}=2

  // $arrTypes{2}=1

  // $arrTypes{3}=6

 

 OB GET PROPERTY NAMES($arrayChildren{3};$arrNames;$arrTypes)

  // $arrayChildren{3} = {"name":"James","age":null}

  // $arrNames{1}="name"

  // $arrNames{2}="age"

  // $arrTypes{1}=2

  // $arrTypes{2}=255