AutoLISP Reference Guide > AutoLISP Functions > V Functions > 
vlax-ldata-get
 
 
 

Retrieves LISP data from a drawing dictionary or an object

(vlax-ldata-get dict key [default-data] [private])

Arguments

dict

A VLA-object, an AutoCAD drawing entity object, or a string naming a global dictionary.

key

A string specifying the dictionary key.

default-data

LISP data to be returned if no matching key exists in the dictionary.

private

If a non-nil value is specified for private and vlax-ldata-get is called from a separate-namespace VLX, vlax-ldata-get retrieves private LISP data from dict.

If you specify private, you must also specify default-data; you can use nil for default-data.

Note that a separate-namespace VLX can store both private and non-private data using the same dict and key. The private data can be accessed only by the same VLX, but any application can retrieve the non-private data.

Return Values

The value of the key item.

Examples

Enter the following commands at the Visual LISP Console window:

_$ (vlax-ldata-put "mydict"
"mykey" "Mumbo Dumbo")

"Mumbo Dumbo"

_$ (vlax-ldata-get "mydict"
"mykey")

"Mumbo Dumbo"

To test the use of private data from a VLX

  1. Enter the following commands at the Visual LISP Console window: 
    _$ (vlax-ldata-put "mydict"
"mykey" "Mumbo Dumbo")

    "Mumbo Dumbo"

    _$ (vlax-ldata-get "mydict"
"mykey")

    "Mumbo Dumbo"
  2. Enter the following code in a file and use Make Application to build a VLX from the file. Use the Expert mode of the Make Application wizard, and select the Separate Namespace option on the Compile Options tab. 
    (vl-doc-export 'ldataput)

    (vl-doc-export 'ldataget)

    (vl-doc-export 'ldataget-nilt)

    (defun ldataput ()

      (princ "This is a test of putting private ldata ")

      (vlax-ldata-put "mydict" "mykey" "Mine! Mine! " T)

    )

    (defun ldataget ()

      (vlax-ldata-get "mydict" "mykey")

    )

    (defun ldataget-nilt ()

      (vlax-ldata-get "mydict" "mykey" nil T)

    )
  3. Load the VLX file.
  4. Run ldataput to save private data: 
    _$ (ldataput)

    This is a test of putting private ldata

    Refer to the code defining ldataput: this function stores a string containing “Mine! Mine!â€

  5. Run ldataget to retrieve LISP data: 
    _$ (ldataget)

    "Mumbo Dumbo"

    Notice that the data returned by ldataget is not the data stored by ldataput. This is because ldataget does not specify the private argument in its call to vlax-ldata-get. So the data retrieved by ldataget is the data set by issuing vlax-ldata-put from the Visual LISP Console in step 1.

    _$ (ldataget-nilt)

    "Mine! Mine! "
  6. Run ldataget-nilt to retrieve LISP data: 
    _$ (ldataget-nilt)

    "Mine! Mine! "

    This time the private data saved by ldataput is returned, because ldataget-nilt specifies the private argument in its call to vlax-ldata-get.

  7. From the Visual LISP Console prompt, issue the same call that ldataget-nilt uses to retrieve private data: 
    _$ (vlax-ldata-get "mydict"
"mykey" nil T)

    "Mumbo Dumbo"

    The private argument is ignored when vlax-ldata-get is issued outside a separate-namespace VLX. If non-private data exists for the specified dict and key (as in this instance), that data will be retrieved.