### 4D Installation Guide

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Alphabetical-list-of-commands.902-976885.en.18.html

Guide for installing 4D.

```APIDOC
## 4D Installation Guide

### Description
This document provides instructions for installing 4D.

### Content
* 4D Installation Guide
```

--------------------------------

### Sequential Execution Example in 4D

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Methods.300-978012.en.html

Demonstrates sequential execution of 4D code, starting from the first line and proceeding to the last. Includes conditional logic and comments.

```4D
QUERY([People])
If(OK=1)
  If(Records in selection([People])=0)
    ADD RECORD([People])
  End if
End if
```

--------------------------------

### Play Welcome Sound on Mac OS

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/JOUER-SON.301-977272.fr.html

This example shows how to play a specific sound resource named 'Bienvenue' upon application startup on Mac OS. This is typically placed in a startup method.

```4D
JOUER SON("Bienvenue")
```

--------------------------------

### Delete the last element of an array

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/DELETE-FROM-ARRAY.301-977324.en.html

This example demonstrates how to delete the last element of an array if the array is not empty. It first gets the size of the array and then calls DELETE FROM ARRAY with the size as the starting element index.

```4D
$vlElem:=Size of array(anArray)
If($vlElem>0)
    DELETE FROM ARRAY(anArray;$vlElem)
End if
```

--------------------------------

### Open Resource File and List String Resources

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/RESOURCE-LIST.301-977576.en.html

This example demonstrates how to open the structure resource file and then list all string list resources. It handles platform differences for file paths and checks if the file was opened successfully before listing resources.

```4D
If(On Windows) 
    $vhStructureResFile:=Open resource file(Replace string(Structure file;".4DB";".RSR")) 
Else 
    $vhStructureResFile:=Open resource file(Structure file) 
End if 
If(OK=1) 
    RESOURCE LIST("STR#";$alResID;$atResName;$vhStructureResFile) 
End if
```

--------------------------------

### Get Coordinates of Objects Starting with 'button'

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/OBJECT-GET-COORDINATES.301-977894.en.html

This example demonstrates how to retrieve the coordinates of all form objects whose names begin with 'button' using the wildcard character '@'. Ensure the interpretation mode of the wildcard character is correctly set if needed.

```4D
OBJECT GET COORDINATES(*;"button@";LEFT;top;RIGHT;bottom)
```

--------------------------------

### Get Text Resource Example

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Resources.300-977556.en.html

This command retrieves text from a text resource. It is a shorter equivalent to using GET RESOURCE with BLOBs.

```4D
ALERT(Get text resource(20000))
```

--------------------------------

### Play Welcome Sound on Macintosh

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/PLAY.301-977272.en.html

This example shows how to play a sound file named 'Welcome Sound' on a Macintosh system. This code is typically placed in a startup method.

```4d
PLAY("Welcome Sound")
```

--------------------------------

### Assigning a Custom Starting Sequence Number

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Sequence-number.301-977675.en.html

If the sequence number needs to start at a number other than 1, add the difference to the result of Sequence number. This example shows how to start numbering at 1000.

```4D
[Table1]Seq Field :=Sequence number([Table1])+999
```

--------------------------------

### Build Applications with Project Files

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/BUILD-APPLICATION.301-977047.en.html

This example demonstrates how to use the BUILD APPLICATION command to build two applications by specifying their respective project XML files. It checks if the first build was successful before attempting the second.

```4d
BUILD APPLICATION("c:\\folder\\projects\\myproject1.xml") 
 If(OK=1) 
     ("c:\\folder\\projects\\myproject2.xml") 
 End if
```

--------------------------------

### Install Event-Handling Method

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/ON-EVENT-CALL.301-978043.en.html

Installs a method to catch events. Pass the method name as a string. To stop catching events, pass an empty string.

```4D
ON EVENT CALL("MyEventHandlerMethod")
```

```4D
ON EVENT CALL("")
```

--------------------------------

### Custom Numbering with Offset

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Numerotation-automatique.301-977675.fr.html

Demonstrates how to start automatic numbering from a value other than 1. This example adds 999 to the next automatic number to make it start from 1000.

```4D
[Table1]NumAuto:=Numerotation automatique([Table1])+999
```

--------------------------------

### Example XML Structure

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/SAX-GET-XML-ENTITY.301-977085.en.html

This is an example of an XML document structure that includes a DOCTYPE declaration with an entity definition, which can be processed by the SAX GET XML ENTITY command.

```xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE body [
    <!ELEMENT body (element*)>
    <!ELEMENT element (#PCDATA)>
    <!ENTITY name "Replacement">
]>
<body>
    <element>Entity updated by &name;</element>
</body>
```

--------------------------------

### List Registered Clients on Startup

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/REGISTER-CLIENT.301-977770.en.html

This instruction can be placed in the On Startup Database Method to create a process that lists all registered 4D clients. It initializes a new process named '4D Client List'.

```4D
PrClientList:=New process("4D Client List";32000;"List of registered clients")
```

--------------------------------

### Get DTD Declaration using DOM Get XML document ref

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/DOM-Get-XML-document-ref.301-977087.en.html

This example demonstrates how to find the DTD declaration of an XML document. It uses DOM Parse XML source to create a document reference, then DOM Get XML document ref to get the document node, and finally DOM GET XML CHILD NODES to find the DOCTYPE node.

```4D
C_TEXT($rootRef)
$rootRef:=DOM Parse XML source("")
If(OK=1)
    C_TEXT($documentRef)
    // we are looking for the document node, since it is the node to which
    // the DOCTYPE node is attached before the root node
    $documentRef:=DOM Get XML document ref($rootRef)
    ARRAY TEXT($typeArr;0)
    ARRAY TEXT($valueArr;0)
    // on this node we look for the DOCTYPE type node among the
    // child nodes
    DOM GET XML CHILD NODES($refDocument;$typeArr;$valueArr)
    C_TEXT($text)
    $text:=""
    $pos:=Find in array($typeArr;XML DOCTYPE)
    If($pos>-1)
    // We retrieve the DTD declaration in $text
        $text:=$text+"Doctype: "+$valueArr{$pos}+Char(Carriage return)
    End if
    DOM CLOSE XML($rootRef)
End if
```

--------------------------------

### Create Interprocess Array and Initialize Elements

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/ARRAY-REAL.301-977332.en.html

This example demonstrates creating an interprocess array of real elements and then iterating through it to set each element's value to its index. Ensure proper handling of interprocess variables.

```4D
ARRAY REAL(◊arValues;50)
For($vlElem;1;50)
    ◊arValues{$vlElem}:=$vlElem
End for
```

--------------------------------

### Get Cookie Header Content

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/GET-HTTP-HEADER.301-977179.en.html

Example of calling the GetHTTPField method to retrieve the 'Cookie' header content.

```4D
$cookie:=GetHTTPField("Cookie")
```

--------------------------------

### Example 1: Exporting Data in Binary Format

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/EXPORT-DATA.301-978046.en.html

This example demonstrates how to export data from all tables in a database in binary format using the EXPORT DATA command and a helper method.

```APIDOC
## Example 1: Exporting Data in Binary Format

### Description
This example illustrates the use of the EXPORT DATA command to export data in binary format. It loops through all database tables and calls the `ExportBinary` method for each.

### Method
APPLY

### Endpoint
/websites/library_4d-japan_doc_4dv12_4d_12_4

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```4d
C_TEXT($ExportPath)
C_LONGINT($i)
$ExportPath:=Select folder("Please select the export folder:")
If(Ok=1)
    For($i;1;Get last table number)
        If(Is table number valid($i))
            ExportBinary(Table($i);$ExportPath+Table name($i);True)
        End if
    End for
End if
```

### Response
#### Success Response (200)
- **OK** (Longint) - Indicates if the export was successful (1 for success, 0 for failure)

#### Response Example
```json
{
  "OK": 1
}
```

### Related Methods
#### ExportBinary Method

##### Description
This method handles the binary export of a specific table, configuring export settings using DOM XML.

##### Parameters
- **$1** (Pointer) - The table to export.
- **$2** (Text) - The path of the destination file.
- **$3** (Boolean) - Whether to export all records.

##### Code Example
```4d
C_POINTER($1) //table
C_TEXT($2) //path of destination file
C_BOOLEAN($3) //export all records
C_LONGINT($i)
C_TEXT($ref)
$ref:=DOM Create XML Ref("settings-import-export")
// Export the table "$1" in '4D' binary format, all the records or only the current selection
DOM SET XML ATTRIBUTE($ref;"table_no";Table($1);"format";"4D";"all_records";$3)
// Definition of fields to export
For($i;1;Get last field number($1))
    If(Is field number valid($1;$i))
        $elt:=DOM Create XML element($ref;"field";"table_no";Table($1);"field_no";$i)
    End if
End for
EXPORT DATA($2;$ref)
If(Ok=0)
    ALERT("Error during export of table "+Table name($1))
End if
DOM CLOSE XML($ref)
```
```

--------------------------------

### Connect to Oracle and Execute Queries

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/SQL-LOGIN.301-977494.en.html

Demonstrates connecting to an Oracle database using SQL LOGIN, executing a query on the Oracle database via SQL EXECUTE, and then executing a query on the local 4D database.

```4D
ARRAY TEXT(aNames;0)
ARRAY LONGINT(aAges;0)
SQL LOGIN("ODBC:MyORACLE";"Marc";"azerty")
If(OK=1)
`The following query will be redirected to the external ORACLE database
SQL EXECUTE("SELECT Name, Age FROM PERSONS";aNames;aAges)
`The following query will be sent to the local 4D database
Begin SQL
  SELECT Name, Age
  FROM PERSONS
  INTO :aNames, :aAges;
End SQL
End if
```

--------------------------------

### Variable Initialization Example

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Error-messages.300-977009.en.html

Initializes a generic variable to False. This is a common starting point for boolean flags.

```4D
$0:=False
```

--------------------------------

### Extract Substring from String

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Substring.301-977469.en.html

Use Substring to get a portion of a string. If the number of characters is not specified, it returns characters from the start position to the end of the string. If the start position is out of bounds, an empty string is returned.

```4D
vsResult:=Substring("08/04/62";4;2) 
 vsResult gets "04"
```

```4D
vsResult:=Substring("Emergency";1;6) 
 vsResult gets "Emerge"
```

```4D
vsResult:=Substring(var;2) 
 vsResult gets all characters except 
 the first
```

--------------------------------

### Get XML Element Value

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/DOM-GET-XML-ELEMENT-VALUE.301-977116.en.html

This example demonstrates how to retrieve the value of an XML element using the DOM GET XML ELEMENT VALUE command. Ensure the element reference and value variable are correctly declared.

```4D
C_TEXT($xml_Element_Ref)
C_REAL($value)

DOM GET XML ELEMENT VALUE($xml_Element_Ref;$value)
```

--------------------------------

### Loading User Preferences with GET RESOURCE

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/SET-RESOURCE.301-977567.en.html

This code snippet shows how to load user preferences from a resource file using the GET RESOURCE command within the On Startup Database Method. It opens the resource file, retrieves the resource data into a BLOB, and then converts the BLOB back into variables. If loading fails, default values are assigned.

```4D
C_BOOLEAN(◊vbAutoRepeat)
C_LONGINT(◊vlCurTable)
$vbDone:=False
$vhResFile:=Open resource file("DB_Prefs")
If(OK=1)
    GET RESOURCE("PREF";26500;$vxPrefData;$vhResFile)
    If(OK=1)
        $vlOffset:=0
        BLOB TO VARIABLE($vxPrefData;◊vbAutoRepeat;$vlOffset)
        BLOB TO VARIABLE($vxPrefData;◊vlCurTable;$vlOffset)
        BLOB TO VARIABLE($vxPrefData;◊asDfltOption;$vlOffset)
        
        $vbDone:=True
    End if
    CLOSE RESOURCE FILE($vhResFile)
End if
If(Not($vbDone))
    ◊vbAutoRepeat:=False
    ◊vlCurTable:=0
    ARRAY STRING(127;◊asDfltOption;0)
End if
```

--------------------------------

### Change String Example 1

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Change-string.301-977482.en.html

Replaces characters starting from the second position. The result is assigned to the vtResult variable.

```4D
vtResult:=Change string("Acme";"CME";2) 
```

--------------------------------

### Create Documentation - CREATE DOCUMENTATION Project Method

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/GET-DOCUMENT-PROPERTIES.301-977421.en.html

Creates or recreates documents on disk based on database records. It determines the save path, creates directories if they don't exist, and prepares to process records for document generation.

```4D
 C_STRING(255;$vsPath;$vsDocPathName;$vsDocName)
 C_LONGINT($vlDoc)
 C_BOOLEAN($vbOnWindows;$vbDoIt;$vbLocked;$vbInvisible)
 C_TIME($vhDocRef;$vhCreatedAt;$vhModifiedAt)
 C_DATE($vdCreatedOn;$vdModifiedOn)
 
 If(Application type=4D Client)
     ` If we are running 4D Client, save the documents  
     ` locally on the Client machine where 4D Client is located  
         $vsPath:=Long name to path name(Application file)
 Else
     ` Otherwise, save the documents where the data file is located  
         $vsPath:=Long name to path name(Data file)
 End if
     ` Save the documents in a directory we arbitrarily name "Documentation"
 $vsPath:=$vsPath+"Documentation"+Char(Directory symbol)
     ` If this directory does not exist, create it  
 If(Test path name($vsPath)#Is a directory)
     CREATE FOLDER($vsPath)
 End if
     ` Establish the list of the already existing documents  
     ` because we'll have to delete the obsolete ones, in other words,  
     ` the documents whose corresponding records have been deleted.  
  ARRAY STRING(255;$asDocument;0)
 DOCUMENT LIST($vsPath;$asDocument)
     ` Select all the records from the [Documents] table  
 ALL RECORDS([Documents])
     ` For each record  
 $vlNbRecords:=Records in selection([Documents])
 $vlNbDocs:=0
 $vbOnWindows:=On Windows
 For($vlDoc;1;$vlNbRecords)
     ` Assume we will have to (re)create the document on disk  
         $vbDoIt:=True
     ` Calculate the name and the path name of the document  
         $vsDocName:="DOC"+String([Documents]Number;"00000")
         $vsDocPathName:=$vsPath+$vsDocName
     ` Does this document already exist?
 
```

--------------------------------

### Get Menu Item Key and Modifiers

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Get-menu-item-key.301-977941.en.html

This example demonstrates how to get the shortcut key code for a menu item and then check its associated modifier keys (Option, Shift). It's useful for handling different shortcut combinations.

```4D
If(Get menu item key(mymenu;1)#0)
    $modifiers:=Get menu item modifiers(mymenu;1)
    Case of
        :($modifiers=Option key mask)
            ...
        :($modifiers=Shift key mask)
            ...
        :($modifiers=Option key mask+Shift key mask)
            ...
    End case
End if
```

--------------------------------

### Open Quick Report Editor for Design/Printing

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/QR-REPORT.301-977714.en.html

This example opens the Quick Report editor, allowing the user to design, save, load, and print reports. Setting the document parameter to Char(1) forces the editor to display. The 'True' parameter enables the wizard.

```4D
QUERY([People]) 
 If(OK=1) 
     QR REPORT([People];Char(1);False;True) 
 End if
```

--------------------------------

### Query and Launch Label Wizard

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/PRINT-LABEL.301-977794.en.html

This example enables user querying of the [People] table. If the query is successful (OK=1), it launches the Label Wizard, allowing the user to design, save, load, and print labels.

```4D
 QUERY([People]) 
 If(OK=1) 
   PRINT LABEL([People];Char(1)) 
 End if
```

--------------------------------

### Get BLOB Size and Add Bytes

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/BLOB-size.301-977297.en.html

This example demonstrates how to get the current size of a BLOB variable and then add 100 bytes to it using the SET BLOB SIZE command. Ensure the 'myBlob' variable is a BLOB type.

```4d
SET BLOB SIZE(BLOB size(myBlob)+100)
```

--------------------------------

### List Directory Contents using External Process

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Get-4D-folder.301-977036.en.html

This example demonstrates how to list the contents of the database folder using the `LAUNCH EXTERNAL PROCESS` command. It's particularly useful on Mac OS where pathnames with spaces require quoting.

```4D
$posixpath:="\""+Get 4D folder(Database Folder Unix Syntax)+"\"" 
$myfolder:="ls -l "+$posixpath 
$in:="" 
$out:="" 
$err:="" 
LAUNCH EXTERNAL PROCESS($myfolder;$in;$out;$err)
```

--------------------------------

### GET HIGHLIGHT

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/GET-HIGHLIGHT.301-977276.en.html

Retrieves the start and end positions of the currently highlighted text within a specified object or field.

```APIDOC
## GET HIGHLIGHT

### Description
The GET HIGHLIGHT command is used to determine what text is currently highlighted in an object. It can be used with an object name (string) or a field/variable reference. The command returns the starting and ending positions of the highlighted text.

### Method
GET

### Endpoint
N/A (This is a 4D language command, not a REST API endpoint)

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Parameters
- ***** (Operator) - Optional - If specified, indicates that the `object` parameter is an object name (string). If omitted, `object` is a field or variable.
- **object** (Field, Variable, Form object) - Required - The name of the object (if `*` is specified) or the field or variable reference (if `*` is omitted).
- **startSel** (Longint) - Required - Output parameter that will store the starting position of the highlighted text.
- **endSel** (Longint) - Required - Output parameter that will store the ending position of the highlighted text (position of the last character plus one).

### Request Example
```4d
GET HIGHLIGHT([Products]Comments;vFirst;vLast)
If(vFirst<vLast)
  ALERT("The selected text is: "+Substring([Products]Comments;vFirst;vLast-vFirst))
End if
```

### Response
#### Success Response (200)
This command does not return a standard HTTP response. It populates the `startSel` and `endSel` parameters with the selection positions.

- **startSel** (Longint) - The starting position of the highlighted text. If `startSel` and `endSel` are equal, the insertion point is positioned before the character specified by `startSel`, and no text is highlighted.
- **endSel** (Longint) - The ending position of the highlighted text (position of the last character plus one).

#### Response Example
(Populated parameters)
`vFirst` = 5
`vLast` = 12

### Notes
- This command is most effective when applied to the area currently being edited.
- It cannot be used with fields in the List form of a subform.
- Text can be highlighted by the user or by the HIGHLIGHT TEXT command.

### See Also
- FILTER KEYSTROKE
- HIGHLIGHT TEXT
```

--------------------------------

### Play Video File on Windows

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/PLAY.301-977272.en.html

This example demonstrates how to play a video file on Windows using the PLAY command. It includes opening and closing the document before playback.

```4d
$DocRef :=Open document("";"AVI") 
 If(OK=1)
     CLOSE DOCUMENT($DocRef)
     PLAY(Document)
 End if
```

--------------------------------

### Calling Custom Error Handlers in 4D

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/ON-ERR-CALL.301-978045.en.html

Examples of how to call the custom ON ERROR CALL method to install and deinstall specific error handling routines. Use a string argument to install a handler, and call without arguments to deinstall.

```4D
gError:=0  
ON ERROR CALL("IO ERRORS")
...
ON ERROR CALL("ALL ERRORS")
...
ON ERROR CALL
...
ON ERROR CALL
```

--------------------------------

### Compact Data File Example (Windows)

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Compact-data-file.301-977049.en.html

Use this command to compact a data file. Ensure the file paths for the data file and the archive folder are correctly specified. The system variable OK will be set to 1 on success and 0 on failure.

```4D
$structFile:=Structure file  
 $dataFile:="C:\Databases\Invoices\January\Invoices.4dd"  
 $origFile:="C:\Databases\Invoices\Archives\January\"  
 $archFolder:=Compact data file($structFile;$dataFile;$origFile)
```

--------------------------------

### Get Pointer to List Box Column

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Managing-List-Box-Objects.300-977998.en.html

Retrieves a pointer to a list box column. Use this when the focus is on a column within a list box. The example shows how to get the column pointer and then access a specific row within that column.

```4D
$Column:=OBJECT Get pointer(Object with focus)
$Row:=$Column->
```

--------------------------------

### Get highlighted text Method

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/FILTER-KEYSTROKE.301-978155.en.html

This section details the 'Get highlighted text' method, explaining its parameters and return values. It also includes a code example demonstrating its usage in conjunction with dictionary lookups and text manipulation.

```APIDOC
## Get highlighted text Method

### Description
This method retrieves highlighted text from a given text string based on start and end positions. It handles cases where the start position is greater than or equal to the end position by searching backward for word boundaries.

### Method
Get highlighted text ( String ; Long ; Long ) -> String
Get highlighted text ( Text ; SelStart ; SelEnd ) -> highlighted text

### Parameters
#### Input Parameters
- **$0** (Text) - Output parameter for the highlighted text.
- **$1** (Text) - The source text string.
- **$2** (Long Integer) - The starting position of the selection.
- **$3** (Long Integer) - The ending position of the selection.

### Code Example
```4d
If($vtHighlightedText#"")
  If($vlStart=$vlEnd)
    $vlStart:=$vlStart-Length($vtHighlightedText)
  End if
  QUERY([Dictionary];[Dictionary]Entry=$vtHighlightedText+"@")
  If(Records in selection([Dictionary])>0)
    $2->:=Insert text($2->;$vlStart;$vlEnd;[Dictionary]Entry)
    $1->:=$2->
    $vlEnd:=$vlStart+Length([Dictionary]Entry)
    HIGHLIGHT TEXT(vsComments;$vlEnd;$vlEnd)
  Else
    BEEP
  End if
Else
  BEEP
End if
```

### Response Example
(No specific response example provided for the method itself, but the code example shows how the output is used.)
```

--------------------------------

### Starting a Local Process in 4D

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Identifiers.300-978006.en.html

Demonstrates starting a local process. Local process names are preceded by a '$' sign.

```4D
$vlProcessID:=New process("P_MOUSE_SNIFFER";16*1024;"$Follow Mouse Moves")
```

--------------------------------

### Get Highlighted Selection from Field

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/GET-HIGHLIGHT.301-977276.en.html

Retrieves the highlighted selection from a specified field. Use this to get the start and end positions of selected text within a field. The command returns significant selection positions only when applied to an area currently being edited.

```4D
GET HIGHLIGHT([Products]Comments;vFirst;vLast)
 If(vFirst<vLast)
     ALERT("The selected text is: "+Substring([Products]Comments;vFirst;vLast-vFirst))
 End if
```

--------------------------------

### Create and Write to a New Document

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Create-document.301-977412.en.html

This example demonstrates creating a new document named 'Note.txt', writing 'Hello' into it, and then closing the document. Ensure the document is correctly created by checking the OK variable.

```4D
C_TIME(vhDoc)
vhDoc:=Create document("Note.txt")
 If(OK=1)
  SEND PACKET(vhDoc;"Hello")
  CLOSE DOCUMENT(vhDoc)
 End if
```

--------------------------------

### Get Format Constant for Picture Variable

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/OBJECT-Get-format.301-977888.en.html

This example demonstrates how to retrieve the format constant applied to a picture variable and display its numerical value. It uses OBJECT SET FORMAT to apply a background format and then OBJECT Get format to retrieve it.

```4D
C_STRING(2;$format)
OBJECT SET FORMAT(*;"myphoto";Char(On Background))
  
$format:=OBJECT Get format(*;"myphoto")
ALERT("Format number:"+String(Character code($format)))
```

--------------------------------

### Select, Expand, and Save Document BLOB

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/EXPAND-BLOB.301-977292.en.html

This example demonstrates opening a document, converting it to a BLOB, checking if it's compressed, expanding it, and then converting it back to a document if expansion was successful. It includes error checking for document and BLOB operations.

```4d
$vhDocRef :=Open document("") 
 If(OK=1) 
 CLOSE DOCUMENT($vhDocRef) 
 DOCUMENT TO BLOB(Document;vxBlob) 
 If(OK=1) 
 BLOB PROPERTIES(vxBlob;$vlCompressed;$vlExpandedSize;$vlCurrentSize) 
 If($vlCompressed#Is not compressed) 
 EXPAND BLOB(vxBlob) 
 If(OK=1) 
 BLOB TO DOCUMENT(Document;vxBlob) 
 End if 
 End if 
 End if 
End if
```

--------------------------------

### Get Field Number using Field Alias

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/Field.301-977454.en.html

This example demonstrates how to get the field number of a field by using its alias (e.g., [Table3]Field2). The '->' operator is used to dereference the alias into a field pointer before passing it to the Field command.

```4d
FieldNum:=Field(->[Table3]Field2)
```

--------------------------------

### Make Resource Preloaded and Purgeable

Source: https://library.4d-japan.com/doc/4Dv12/4D/12.4/SET-RESOURCE-PROPERTIES.301-977562.en.html

This example sets a resource to be both preloaded and purgeable. Verify the resource ID and file variable are correct.

```4D
SET RESOURCE PROPERTIES('STR#';17000;Preloaded resource mask+Purgeable resource mask;$vhResFile)
```