[Baypiggies] Discussion for newbies/beginner night talks

[Aahz]

[top-posting for once to preserve Dennis's code without require people
to read over it for my material]

There are several aspects to your code that I would object to if you
were submitting it to me for code review:

* Your internal indentation makes this difficult to maintain

* URL generation should be done with function calls, for example:

    def make_link(url, **kwargs):
        q = url_quote
        params = [ q(i[0])+'='+q(i[1]) for i in kwargs.items() ]
        params = '&'.join(params)
        return url + '?' + params

    make_link('edt_main.py', slct='edit', class='tree_open32',
        index=key, act=act)

* Using += makes for bad performance

* Hardcoding image size attributes is horrible

* For that matter, hardcoding URLs is a Bad Idea

* Interleaving program logic with HTML makes it difficult to follow both

Triple-quoting doesn't solve any of these problems directly, but it
would allow you to take more of a templating approach, particularly if
you used dict interpolation instead of tuple interpolation.


On Fri, Feb 09, 2007, Dennis Reinhardt wrote:
>
> Here is a code fragment from my talk last night (foil 15, I believe).  How 
> would you re-write this to utilize triple quoting?  The task here is to 
> build a two level visual tree structure:
> 
> # build entire initial tree structure
> def init_tree(ht_obj):
>      html = "<table border=0>"
>      index = 0
>      last_exe = ""
>      for xml_entry in util_actwin.display_list("enm", "+"):
>          exe_name = str_extract(xml_entry, ["enm"])
>          keye   = safe_int(str_extract(xml_entry, ["key"]))
>          act = str_extract(xml_entry, ["act"])
>          #logger("init_tree %s %s" % (keye, exe_name))
>          fname, exe = exe_name.split(".")
>          if fname != last_exe:
>              html += "<tr>"
>              if fname == expanded_node:
>                  html += "<td><img src=image/slct32.gif border=0></td>"
>              else:
>                  html += "\r\n<td><a 
> href=edt_main.py?slct=expand&fname=%s>" % fname
>                  html += "<%s></a></td>\r\n" % hovered_img(ht_obj, index)
>              html += "<td><img src=%s width=32 height=32></td>" % 
> get_program_image(fname)
>              html += "<td>%s</td>" % fname
>              html += "<td>&nbsp;</td>"
>              html += "</tr>"
>          if fname == expanded_node:
>              html += "<tr>"
>              html += "<td>&nbsp;</td>"
>              parm_index = safe_int_default(ht_obj.param("index"), -1)
>              if parm_index == keye:
>                  html += "<td><img src=image/slct32.gif border=0></td>"
>                  html += "<td><img src=%s " % get_action_image(xml_entry)
>                  html +=     "width=32 height=32 border=0></td>"
>              else:
>                  html += "<td><a href=edt_main.py?slct=edit"
>                  html +=     "&class=tree_open32"
>                  html +=     "&index=%s"       % keye
>                  html +=     "&act=%s"         % act
>                  html +=     "><%s></a></td>" % hovered_img(ht_obj, index)
>                  html += "<td><img src=%s " % get_action_image(xml_entry)
>                  html +=     "width=16 height=16 border=0></td>"
>              html += "<td>%s</td>" % get_caption(xml_entry)
>              html += "</tr>"
>          else:
>              pass
>          last_exe = fname
>          index += 1
>      html += "</table>"
>      return html

-- 
Aahz (aahz at pythoncraft.com)           <*>         http://www.pythoncraft.com/

"I disrespectfully agree."  --SJM