I think this is because it is a C++ lib.
NativeBoost cannot be used with C++ lib.
It is a problem of call convention that is not the same from C to C++.As I discuss with some people it seems be a complexe problem, each C++ compiler seems have it own convention.But Igor can maybe be more accurate about that.
A C wrapper to call C++, which should work.
On 23 May 2014, at 02:36, Torsten Bergmann <astares@gmx.de> wrote:Hi,
as there was no responded so far I tried to track the problem deeper and did a short test
client in C/C++ to verify if I can call WKHTMLTOPDF there and generate a PDF and to
compare to the Pharo/NativeBoost client.
Attached is the according CPP file which works and results in a PDF with the google
homepage.
I also additionally implemented the callback functions in the Pharo wrapper and
using the error handling I noticed that the component returns "Failed loading page http:// ..."
With that info I compared the C/C++ calls to the Pharo/NativeBoost calls more deeply and
found out that in C/C++ the following call for an object setting works (by returning 1):
// this returns 1 in C/C++ which is OK
int a = wkhtmltopdf_set_object_setting(os, "page", "http://www.google.de");
printf("object set %i",a);
while in Pharo the same call fails (by returning 0):
"The following call failed and returns 0 instead of 1"
self setObjectSetting: 'page' to: 'http://www.google.de' in: os.
I checked how I wrapped this API call again and again - it is fine from my side:
setObjectSetting: aName to: value in: settings
<primitive: #primitiveNativeCall module: #NativeBoostPlugin>
^NBFFICallout stdcall: #(int wkhtmltopdf_set_object_setting(wkhtmltopdf_object_settings* settings, char* aName, char* value)) module: 'wkhtmltox.dll'
and I still have no idea why it fails.
Especially because "wkhtmltopdf_set_object_setting" function is not different from "wkhtmltopdf_set_global_setting" which is exactly the same way wrapped, works
and returns 1 in exactly the same example.
I would really appreciate if someone could have a second look...
To reproduce on Windows:
1. Download the 32 bit version of WKHTML from http://wkhtmltopdf.org and install it
2. Copy the "wkhtmltox.dll" to either the folder of the VM executable
or the Windows directory so it can be found
3. Load the package WKHTML2PDF-Core-TorstenBergmann.7
from http://smalltalkhub.com/#!/~TorstenBergmann/WKHTML2PDF into Pharo 3.0#30848
4. Check the Transcript while evaluating:
WKPDFLibrary example
One can see that within this code #setObjectSetting:to:in: fails while #setGlobalSetting:to:in:
works.
Maybe I just do not see the obvious. Help is appreciated. Thanks in advance!
bye
T.
<main.cpp>