> On Mar 25, 2020, at 8:21 PM, Keisuke Miyako via 4D_Tech
> <4d_tech@lists.4d.com> wrote:
>
> sometimes, it might just be easier to read the entire text with
>
> Document to text (which can normalise the EOL character)
I took Keisuke’s advice to heart and looked closer at Document to text. I did
not realize that it provided a means to handle any EOL confusion between Mac
and Windows. For me this makes the use of Document to text a much better way to
read the contents of a document by row than Receive packet.
In an effort to duplicate Receive packet’s functionality when used in a repeat
loop to get rows of a tab delimited text document, I created a wrapper method
as a replacement for Receive packet.
I am posting this method here in the event someone on on the NUG might find it
useful. More importantly for me, however, perhaps to get some feedback with
regard to anything I may have overlooked or anything I may need to do to clean
it up.
It was written in a v14 database so does not use any of the newer features in
v17 and later like Is Windows and/or objects.
Thanks for any feedback.
John
------------------------------
// Method: ReceivePacket_DocToText
(->pathToDocumentVariable;->VariableToHoldDocContents;BreakMode)
// ----------------------------------------------------
// Created by: John Baughman
// ----------------------------------------------------
// Description
//Replacement for Receive Packet using Document To Text
// Parameters
C_POINTER($1;$pathPtr) //$1 is a pointer to the variable holding the path to
the document.
//In a repeat loop you can put an empty string in the variable to allow the
user to pick the document using Document Select.
//The variable will be updated to contain the chosen path for subsequent
calls for rows in the loop.
//If the user cancels the Select Document, $rowText:="", and
$documentTextPtr->:=“"
C_POINTER($2;$documentTextPtr) //Pass an empty text variable in the first call
and it will be loaded from the document with Document to text.
//The variable will be loaded with the document contents minus the row being
returned.
C_TEXT($0;$rowText) //$RowText will hold the first row in the $DocumentTextPtr
variable and returned in $0.
//The first row in the $DocumentTextPtr variable wil be removed.
C_LONGINT($3;$breakMode) //Document to Text will convert the EOL character to
the following desired break mode constants...
//Document with CR
//Document with CRLF
//Document with LF
//Document with native format
//Example Call
If (False)
C_TEXT($TextValue;$path)
$TextValue:=""
$path:=""
Repeat
$rowText:=ReceivePacket_DocToText (->$path;->$TextValue;Document with CR)
//If TextValue is “” then the text will be loaded from the document
and returned minus the first row in TextValue
//Subsequent calls will return first row in $rowText and return the
text minus the first row in TextValue.
If (rowText#””)
//handle the row
End if
Until (TextValue =“") //note: I do not use the ok variable as I found that
the ok variable may get set incorrectly by 4D if the last row does not have CR.
End if
// ----------------------------------------------------
$pathPtr:=$1
$DocumentTextPtr:=$2
$breakMode:=$3
$rowText:=""
If ($pathPtr->="")
//They want to select the document
ARRAY TEXT($aSelected;0)
$path:=Select document("";"*";"";0;$aSelected)
If (ok=1)
$pathPtr->:=$aSelected{1}
End if
End if
If (ok=1)
If ($DocumentTextPtr->="")
//Document has not yet been loaded
If (Is Windows)
$documentTextPtr->:=Document to
text($pathPtr->;"ANSI_X3.4-1986";$breakMode)
$stopCharacter:="\r\n"
Else
$documentTextPtr->:=Document to
text($pathPtr->;"MacRoman";$breakMode)
$stopCharacter:="\r"
End if
//else document has been loaded use text in DocumentTextPtr
End if
$found:=False
Case of
: ($breakMode=Document with CR)
$stopCharacter:="\r"
: ($breakMode=Document with LF)
$stopCharacter:="\n"
: ($breakMode=Document with CRLF)
$stopCharacter:="\r\n"
//else
//$stopCharacter was set to the default for the
platform above following document to text
End case
If (Position($stopCharacter;$DocumentTextPtr->)=0)
//Assumes that this is the last row without an EOL character.
Otherwise it is an error
$rowText:=$documentTextPtr-> //return what is left
ok:=0 //we are done. Recieve packet sets ok to 0 when done in
a repeat loop so I am doing the same here. I have found the ok variable to be
unreliable in this method
$documentTextPtr->:=“” //nothing left
Else
$rowText:=Substring($documentTextPtr->;1;Position($stopCharacter;$documentTextPtr->)-1)
//put the first row without the stop character in $rowText
$documentTextPtr->:=Replace
string($documentTextPtr->;$rowText+$stopCharacter;””). //return the document
text minus the first row in documentTextPtr
End if
Else
$DocumentTextPtr->:=""
End if
$0:=$rowText. //return the first row
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