[SOLVED] LAMW -   jExpression ends application on errors
lazarus / 43-Android

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guaracy · 2021-10-04 13:31

Any way to catch java exceptions?

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 procedure
TAndroidModule1.jButton1Click(Sender: TObject);var  r: Double;begin 
jExpression1.SetFormula('3*(2+2)',[]);  // OK 
jExpression1.SetFormula('2/0',[]);  // crash : Division by zero 
jExpression1.SetFormula('2/4+',[]); // crash : Invalid number of
operands available for '+'  try    r:=jExpression1.Evaluate(); 
except    ShowMessage('ERROR');  end;  ShowMessage(FloatToStr(r));end;

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jmpessoa · 2021-10-04 17:16

Hi, guaracy!

I will try improve the jExpression component!

Thank you!

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jmpessoa · 2021-10-05 22:45

Done!

1) Added "inner" java handling to ArithmeticException ("Division by
zero")...

2) New methods
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    
function IsExpressionValid(_checkVariablesSet: boolean): boolean;    
function CanEvaluate(_checkVariableSet: boolean): boolean;    function
GetValue(): double;   
3) Updated demo "AppExpressionDemo1"

Thank you!

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engkin · 2021-10-06 00:17

In general, exceptions inside Java code can be tested with
ExceptionOccurred, and should be cleared with ExceptionClear.
Without the latest update by jmpessoa you can write:
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 procedure T
AndroidModule1.jButton1Click(Sender:TObject);{$push}{$WriteableConst+}
const  eIdx:integer=0;{$pop}var  e:array[0..2] of
String=('3*(2+2)','2/0','2/4+');  r:string;begin 
jExpression1.SetFormula(e[eIdx],[]); 
r:=jExpression1.Evaluate.ToString;  if
gApp.Jni.jEnv^.ExceptionOccurred(gApp.Jni.jEnv)<>nil then  begin   
gApp.Jni.jEnv^.ExceptionClear(gApp.Jni.jEnv);//<--- if you don't clear
it, your app will be killed    r:='ERROR';  end;  
ShowMessage(e[eIdx]+' = '+r);  inc(eIdx); if eIdx>High(e) then
eIdx:=0;end

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guaracy · 2021-10-08 18:02

Thanks jmpessoa.

Errors like unbalanced parentheses must be catch inside SetFormula
function in Java. Otherwise the application is aborted.

Sorry for the code (my first Java lines) but worked here.

Code: Java  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i     public
void SetFormula(String _expression, String[] _variables) {        try
{            mExprBuilder = new ExpressionBuilder(_expression);      
    mExprBuilder.variables( _variables);            mExpr =
mExprBuilder.build();        } catch (Exception e) {            mExpr
= null;            Toast toast = Toast.makeText(controls.activity,
"Exception on Builder!"/*e.getMessage()*/, Toast.LENGTH_LONG);       
   if (toast != null) {               
//toast.setGravity(Gravity.BOTTOM, 0, 0);               
toast.show();            }            Log.e("LAMW", "Exception on
Builder!", e);        }    }

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jmpessoa · 2021-10-08 18:52

QuoteSorry for the code (my first Java lines) but worked here.

Good code!

I will improve based on your code!

Thank you!

P.S.

Done!