#611 URGENT fail to write attribute with PyTango 8.0.3

[Sergi Rubio]

This is bug is quite blocking as it causes problems with ALL our PyTango device servers.

The PyTango 8 documentation states the following:

<quote>
This is what you would do with PyTango <= 3.0.4:</quote>

flatList = []
attr.get_write_value(flatList)
print "flatList =", flatList

flatList = [ 1, 2, 3, 4 ]

You can still do it with PyTango 8. However I recommend:
...

Therefore attr.get_write_value(flatList) in PyTango 8.* should work, but it fails with the following exception:

---

PyDs_PythonError: ArgumentError: Python argument types in
WAttribute.get_write_value(WAttribute, list)
did not match C++ signature:
get_write_value(Tango::WAttribute {lvalue} self, PyTango::ExtractAs extract_as=PyTango._PyTango.ExtractAs.Numpy)

---

Having the old syntax allowed is critical to us; because this issue does not allow us to update Tango8 at all in any subsystem.

Sergi Rubio

[Frédéric PICCA]

Hello Soleil is also affected by this problem.

I am wondering if the culprite is not this commit 2012-09-04 10:03:56

merge with branch Release_8_0_0_py3k

where, this code was removed.

~~~~~~
@@ -345,47 +437,6 @@ namespace PyWAttribute
/// @{

 template<long tangoTypeConst>

• void __get_write_value_pytango3(Tango::WAttribute &att, boost::python::list &seq)
• {

• typedef typename TANGO_const2type(tangoTypeConst) TangoScalarType;

• const TangoScalarType *ptr;

• long length = att.get_write_value_length();

• att.get_write_value(ptr);

• for (long l = 0; l < length; ++l)
• {
• seq.append(ptr[l]);
• }

• }

• template<>
• void __get_write_value_pytango3<tango::dev_string>(Tango::WAttribute &att,</tango::dev_string>
• boost::python::list &seq)
• {

• const Tango::ConstDevString *ptr;

• long length = att.get_write_value_length();

• att.get_write_value(ptr);

• for (long l = 0; l < length; ++l)
• {
• seq.append(ptr[l]);
• }

• }

• inline void get_write_value_pytango3(Tango::WAttribute &att,
• boost::python::list &value)
• {
• long type = att.get_data_type();
• TANGO_CALL_ON_ATTRIBUTE_DATA_TYPE(type, __get_write_value_pytango3, att, value);

• }

  
  -
• template<long tangotypeconst="">
  void __get_write_value_scalar(Tango::WAttribute &att, boost::python::object* obj)
  {
  typedef typename TANGO_const2type(tangoTypeConst) TangoScalarType;
  @@ -404,33 +455,6 @@ namespace PyWAttribute
  ~~~~~</long>

[Tiago Coutinho]

Fixed in SVN branch PyTango_8_0_4_dev.
Will become visible in next PyTango release 8.0.4

Thanks for reporting.