$Exist$

Checks whether a given Zim object exists in a Zim directory.

Syntax

$exist$(Zim directory name, object name, object type)

Parameters

Zim directory name

A character string or an expression that evaluates to a character string, naming the Zim directory to which the object would belong

object name

A character string or an expression that evaluates to a character string specifying the object name to be checked in the Zim directory name for its existence

object type

A number or an expression that evaluates to a number determining the type of the object name

 

Return Value

It returns a $True value if the object name is defined in the Zim directory and is of the specified object type.

It returns a $False value if the object name is not defined in the Zim directory or is not of the specified object type or the Zim directory name is already accessed.

If the object type is 0 (zero), the function will return the object type of the object for subsequent reading of the status of this object (see example).

If the object type is non-zero and the Zim directory name is empty (""), then the return value is the owning directory name of that object.

Comments

The types of the object are described as the following table:

Object Type

Meaning

0

Returns the Object Type

1

A Null Object

2

Shadow Directory

3

Directory

4

Entity Set

5

Field

6

Relationship with no Fields

7

Relationship with Fields

8

Set

9

Document

10

List

11

Form

12

Role

13

Variable

14

Display

15

Virtual Field

16

CSet

17

Window

18

Constant

19

Menu

 

Examples

Check whether the directory "Accounting" is defined in Zim:

$exist$("ZIM", "Accounting", 2)

Investigate the type of the object "Customers" in directory Zim and then test whether it exists or not:

let Var = $exist$("ZIM", "Customers", 0)
$exist$("ZIM", "Customers", Var)