In brief and as a reminder, I need a way to quickly assign values to variables
received from a web page. The problem I have is that if a field submitted on a
web page does not exist it produces a runtime error messages in a compiled
data base indicating a bad usage of a pointer. The process stops until continue
or abort is selected.
I want a way to just ignore any instances where the variable does not exist in
the data base. Lee's suggestion of putting my 25,000 variables in an object
and using OB Is Defined looked like a fast easy solution. Unfortunately I was
sloppy over the last 25 years it turns out and I have not consistently made use
of case convention in my variable names. Since OB Is Defined is case sensitive
I cannot use it unless I spend days cleaning up my code. I will put that on the
list for the future, but, in the meantime, does anyone have any other quick
solutions?
Keisuke made a reference to using Not(Nil( $p))) and Type($p->) following Get
pointer. I played with that but can't quite see how that would work. In essence
I would just like to bypass or ignore any situations where the
arr_Web_Field_Name is not actually a defined variable name so I don't get the
runtime error messages related to bad usage of a pointer which in turn halts
the process until I click the continue button.
Any suggestions? Hopefully I'm just missing something obvious and simple here.
WEB GET VARIABLES(arr_Web_Field_Name;arr_Web_Field_Value)
For ($i;1;Size of array(arr_Web_Field_Name))
$p:=Get pointer(arr_Web_Field_Name{$i})
$p->:=arr_Web_Field_Value{$i}
End for
Thanks again,
Mike McCall
ORIGINAL POST FROM NOVEMBER 9, 2016:
Thanks in advance for any assistance,
This is probably something I should know and clearly something I could do
differently but for now I'm hoping for an easy solution.
I believe 4D is moving away from the Automatic Variable Assignment option when
using a browser to access a 4D enabled Web server. As they do that I believe
the replacement approach is to use Web Get Variables. Because we have a silly
number of variables (i.e., 20,000) which could be called from any given web
page we'd like use something similar to the code below to assign the values
received using Web Get Variables to their corresponding and existing variables
using pointers. That would allow us to move away from the Automatic variable
assignment without a major rewrite to our code.
In an uncompiled application the code works fine.
In a compiled application it works fine as well unless someone were to
maliciously or somehow inadvertently submit a web page with a field name which
was not defined in our application. In brief if they modified an html form to
submit to our application and added a non-existent field, then a -20010 error -
Bad usage of pointer or pointer to an unknown variable message would be
generated and the connection would hang until we clicked OK on the message on
the server.
Is there any way we could avoid this from happening? We were hopeful that using
"undefined" would help but that doesn't work in a compiled database.
Aside from a major rewrite of how we handle the fields from a form statement
does anyone know how we could just ignore unknown field names o handle them
without the error message being generated in a compiled database?
Code used during On Web Authentication
C_TEXT($1;$2;$3;$4;$5;$6)
C_TEXT(vtSystem_Password;vtSystem_User;vtSystem_Server_IP;vtSystem_Client_IP;vtSystem_Hdr;vtSystem_URL)
$0:=True
vtSystem_URL:=$1
vtSystem_Hdr:=$2
vtSystem_Client_IP:=$3
vtSystem_Server_IP:=$4
vtSystem_User:=$5
vtSystem_Password:=$6
C_TEXT(Dummy;Web_TM_Accessed_By) //variables which are not typed explicitly or
by reference during compilation. They could be deleted
$vt_GetOrPost:=""
$vt_GetOrPost:=Substring(vtSystem_Hdr;1;4)
If ($vt_GetOrPost="Post")
ARRAY TEXT(arr_Web_Field_Name;0)
ARRAY TEXT(arr_Web_Field_Value;0)
WEB GET VARIABLES(arr_Web_Field_Name;arr_Web_Field_Value)
C_BOOLEAN($test)
// $start:=Milliseconds
For ($i;1;Size of array(arr_Web_Field_Name))
//ALERT(string($i)+" - "+arr_Web_Field_Name{$i})
Case of
: (arr_Web_Field_Name{$i}="vbFileName")
C_TEXT($vPartName;$vPartMimeType;$vPartFileName;$vDestinationFolder)
C_BLOB($vPartContentBlob)
C_BLOB(vbFileName)
C_LONGINT($i)
//$vDestinationFolder:=Get 4D folder(HTML
Root folder)+"photos"+Folder separator
For ($j;1;WEB Get body part count) //for each
part
WEB GET BODY
PART($i;$vPartContentBlob;$vPartName;$vPartMimeType;$vPartFileName)
If ($vPartFileName#"")
vbFileName:=$vPartContentBlob
vt_OrignalFileName:=$vPartFileName
vt_cttype:=$vPartMimeType
//BLOB TO
DOCUMENT($vDestinationFolder+$vPartFileName;$vPartContentBlob)
End if
End for
Else
// $test:=OB Is
defined(<>Obj_Defined_Text_Variables;arr_Web_Field_Name{$i})
$test:=True
If ($test)
$p:=Get pointer(arr_Web_Field_Name{$i})
$p->:=arr_Web_Field_Value{$i}
Else
// Alert("The following field was not
found: "+arr_Web_Field_Name{$i})
End if
End case
End for
// ALERT("01 - "+String(Milliseconds-$start)) // I get 0
End if
Mike McCall
Facilitate.com
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