[albatross-users] problem with static data members in templates ...

[Francis Meyvis]

Hoi,

In a HTML form I present a database record/row data for editing.
The class cRow abstacts the db data.
The class in a simplified form is presented next:


class cRow():

   mFld = cField("table_name")

   def __init__(s, atData):
     mlData = list(atData)    # convert db query result tuple to list

   def __getitem__(s, i): return mlData[i]
   def __setitem__(s, i, v): mlData[i] = v

   def validate(): ... # validate the data in mlData
   def update(): ... # update database with changed mlData


cField is a static datamember to conserve memory
(it is the same for all rows of that specific table).
cField uses the DB API II ".description" to query the table format.
Using this information it adds datamembers to itself during __init__()
e.g.
mFld.mVal.NAME evaluates to a numberic index for
indexing the list "mlData" to find the value
corresponding to the column named 'NAME'


In the template I do something like this:

<al-input type="text" name="row[row.mFld.mVal.NAME]"/>

The idea was :-( that "row" is found in context.locals.
The advantage I saw, was that row's mlData is read and write
by albatross templating mechanism.
No need for me to start adding accessor functions.

But is does not work, I get the trace dump error below
(I use slight different variable names).

This could be a python 2.1 limitation however.
When I do a "dir(row)" I only see row's normal data members.
Not the static data member mFld.
In my python code (not template) itself this mechanism
for manipulating db data through cRow works.

Does someone on the list has a simple solution?

Many thanks,
francis




Template traceback (most recent call last):
   File "tmpl/prjAdd.html", line 34, in al-form
   <al-form method="post">
   File "tmpl/prjAdd.html", line 40, in al-input
         <td><al-input type="text" name="prjName" 
expr="xprj[xprj.mFld.mVal.OWNERID]"/></th>

Traceback (most recent call last):
   File "/usr/lib/python2.1/site-packages/albatross/app.py", line 147, 
in run
     self.display_response(ctx)
   File "/usr/lib/python2.1/site-packages/albatross/app.py", line 305, 
in display_response
     func(ctx)
   File "page/prjAdd.py", line 58, in page_display
     aoCtx.run_template(mode.GetTmplName(aoCtx))
   File "/usr/lib/python2.1/site-packages/albatross/app.py", line 65, in 
run_template
     templ.to_html(self)
   File "/usr/lib/python2.1/site-packages/albatross/template.py", line 
358, in to_html
     self.content.to_html(ctx)
   File "/usr/lib/python2.1/site-packages/albatross/template.py", line 
150, in to_html
     item.to_html(ctx)
   File "/usr/lib/python2.1/site-packages/albatross/tags.py", line 242, 
in to_html
     EnclosingTag.to_html(self, ctx)
   File "/usr/lib/python2.1/site-packages/albatross/template.py", line 
189, in to_html
     self.content.to_html(ctx)
   File "/usr/lib/python2.1/site-packages/albatross/template.py", line 
150, in to_html
     item.to_html(ctx)
   File "/usr/lib/python2.1/site-packages/albatross/tags.py", line 117, 
in to_html
     self.unbound_to_html(self, ctx)
   File "/usr/lib/python2.1/site-packages/albatross/tags.py", line 122, 
in generic_to_html
     name, value = self.get_name_and_value(ctx)
   File "/usr/lib/python2.1/site-packages/albatross/tags.py", line 90, 
in get_name_and_value
     return name, self.eval_expr(ctx)
   File "/usr/lib/python2.1/site-packages/albatross/tags.py", line 36, 
in eval_expr
     return ctx.eval_expr(self.expr)
   File "/usr/lib/python2.1/site-packages/albatross/context.py", line 
320, in eval_expr
     return eval(expr, self.__globals, self.locals.__dict__)
   File "<albatross>", line 0, in ?
AttributeError: mFld