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4D Write v14

WR Direct find


WR Direct find ( blob ; charString ; wholeWord ; upperCase ) -> Function result

Parameter	Type	Description
blob	BLOB	Blob containing a 4D Write area
charString	Alpha	Character string to be searched for
wholeWord	Integer	0=partial match 1=whole word
upperCase	Integer	0=ignore uppercase 1=takes uppercase into account
Function result	Longint	Search status

Description

The WR Direct find command allows you to directly search for a character string in a BLOB that contains a 4D Write area. Using this command does not require the BLOB to be opened in a 4D Write area first. This means that this command executes very quickly.

If the character string is found, WR Direct find returns the position of the character string in the text.

If the search was unsuccessful, WR Direct find returns -1.

If blob does not represent the contents of a 4D Write area, WR Direct find returns -2.

wholeWord and upperCase allow you to choose some options for the search.

In the wholeWord parameter, you can pass one of the following constants, found in the WR Parameters theme:

Constant	Type	Value	Comment
wr partial match	Longint	0	The character string can either be a whole word or part of a longer word
wr whole word	Longint	1	To be found, the word must occur between separator characters (spaces, punctuation marks, etc.)

In the upperCase parameter, you can pass one of the following constants, found in the WR Parameters theme:

Constant	Type	Value	Comment
wr ignore uppercase	Longint	0	The search is not case sensitive and will find both “Hello”, “hello” and “HELLO“... if you search for “HELLO”
wr case sensitive	Longint	1	The search is case sensitive and will not find “Hello” if you are searching for “HELLO”

Example

This example proposes a keyword-based search method that searches in a selection of records. Your database manages cooking recipes. The 4D Write areas are saved in BLOB fields. You want to be able to find all recipes that use a specific ingredient. Here is the corresponding method, which is very fast:

 ToFind:=Request("Enter the ingredient(s) to find:")

  `Creating an empty set in which all found records will be placed

 CREATE EMPTY SET([MyRecipes];"FoundRecords")

 ALL RECORDS([MyRecipes]) `Browsing all the table selection

 While(Not(End selection([MyRecipes])))

    If(WR Direct find([MyRecipes]BlobRecipe_;ToFind;wr whole word;wr case sensitive)>0)

  `If the ingredient is found, the record is added to the set

       ADD TO SET([MyRecipes];"FoundRecords")

    End if

    NEXT RECORD([MyRecipes])

 End while

 USE SET("FoundRecords")

 OUTPUT FORM([MyRecipes];"Output")

 MODIFY SELECTION([MyRecipes];*)