[SOLVED] SIGSEGV on web form processing
lazarus / 38-Networking and Web Programming

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lennit · 2015-12-09 13:47

Hello,
I am playing around with Benibella's Internet tools to retrieve data
from a web form. In order to learn how to use it, I started with a
simple HTML I made and the the source code I apply. Somehow though it
gives me a SIGSEGV error when I try to use another template, other
than the one pointing to the first element on the page.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  const 
 EXAMPLE_TEMPLATE :string='<table
name="tabdata"><tr><td>{.}</td><td>{.}</td></tr>*</table>'; 
 temp1:string='<input name=e1>{e1:=@value}</input>'; 
 temp2:string='<input name=e2>{e2:=@value}</input>';var  Form1:
TForm1;  content:string;  m:integer;implementation {$R *.lfm} { TForm1
} procedure TForm1.retrieveDataClick(Sender: TObject);begin 
m:=strtointdef(indexOfItem.Text,0);  content:=retrieve(address.Text); 
case m of   0:process(content, temp1);   1:process(content, temp2); 
 2:process(content, EXAMPLE_TEMPLATE);   3:process(content,
EXAMPLE_TEMPLATE);  end; 
responseEdit.Text:=processedVariables.get(m).toString;  content:=''; 
processedVariables.Free;end;                                   
This is the index.html against which I am testing it.
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i <!doctype
html><html><title>Untitled Page</title><body><input name=e1
value="300"></input><input name=e2 value="500"></input><table
name=tabdata><tr><td>20</td><td>30</td></tr></body></html> 
It only works for the first template, in other words for the first
input box in the web page. For any other index it gives me SIGSEGV.
What am I doing wrong? Am I trying to overstep the possibilities which
Internet Tools offer?

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lennit · 2015-12-09 14:13

I got this 
Instead of
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
processedVariables.Free;I should have used
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
processedVariables.Clear;Modifying the template to this
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i const 
 EXAMPLE_TEMPLATE :string='<table name="tabdata"><tr><td>{.}</td><td>{
.}</td><td>{.}</td><td>{.}</td></tr>*</table>';   temp1:string='<input
name=e1>{e1:=@value}</input><input name=e2>{e2:=@value}</input>'; 
 temp2:string='<input name=e2>{e2:=@value}</input>';var  Form1:
TForm1;  content,con1,con2,con3:string;  m:integer;implementation {$R
*.lfm} { TForm1 } procedure TForm1.retrieveDataClick(Sender:
TObject);begin  m:=strtointdef(indexOfItem.Text,0); 
content:=retrieve(address.Text);  case m of   0:process(content,
temp1);   1:process(content, temp1);   2:process(content,
EXAMPLE_TEMPLATE);   3:process(content, EXAMPLE_TEMPLATE);  end; 
responseEdit.Text:=processedVariables.get(m).toString;  content:=''; 
processedVariables.clear;end;                                        
    got me out of one more SIGSEGV.
I hope that helps someone to skip the struggle implementing Internet
Tools.

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BeniBela · 2015-12-09 16:34

yeah, never call free directly, if you did not call create

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lennit · 2015-12-09 19:22

Thank you, Benibella  Your tool helped me a lot with my current
project.