How to use the html.A function in html

href = linkto(r, 'table', tablename)
                    except TypeError:
                        href = '%s/%s/%s' % (linkto, tablename, r_old)
                    r = A(r, _href=href)
                elif isinstance(field.type, str) and field.type.startswith('reference'):
                    if linkto:
                        ref = field.type[10:]
                        try:
                            href = linkto(r, 'reference', ref)
                        except TypeError:
                            href = '%s/%s/%s' % (linkto, ref, r_old)
                            if ref.find('.') >= 0:
                                tref,fref = ref.split('.')
                                if hasattr(sqlrows.db[tref],'_primarykey'):
                                    href = '%s/%s?%s' % (linkto, tref, urllib.urlencode({fref:r}))
                        r = A(represent(field,r,record), _href=str(href))
                    elif field.represent:
                        r = represent(field,r,record)
                elif linkto and hasattr(field._table,'_primarykey') and fieldname in field._table._primarykey:
                    # have to test this with multi-key tables
                    key = urllib.urlencode(dict( [ \
                                ((tablename in record \
                                      and isinstance(record, Row) \
                                      and isinstance(record[tablename], Row)) and
                                 (k, record[tablename][k])) or (k, record[k]) \
                                    for k in field._table._primarykey ] ))
                    r = A(r, _href='%s/%s?%s' % (linkto, tablename, key))
                elif isinstance(field.type, str) and field.type.startswith('list:'):
                    r = represent(field,r or [],record)
                elif field.represent:
                    r = represent(field,r,record)
                elif field.type == 'blob' and r:

and isinstance(record,Row) \
                        and isinstance(record[tablename],Row):
                    r = record[tablename][fieldname]
                elif fieldname in record:
                    r = record[fieldname]
                else:
                    raise SyntaxError, 'something wrong in Rows object'
                r_old = r
                if not field:
                    pass
                elif linkto and field.type == 'id':
                    try:
                        href = linkto(r, 'table', tablename)
                    except TypeError:
                        href = '%s/%s/%s' % (linkto, tablename, r_old)
                    r = A(r, _href=href)
                elif field.type.startswith('reference'):
                    if linkto:
                        ref = field.type[10:]
                        try:
                            href = linkto(r, 'reference', ref)
                        except TypeError:
                            href = '%s/%s/%s' % (linkto, ref, r_old)
                            if ref.find('.') >= 0:
                                tref,fref = ref.split('.')
                                if hasattr(sqlrows.db[tref],'_primarykey'):
                                    href = '%s/%s?%s' % (linkto, tref, urllib.urlencode({fref:r}))
                        r = A(represent(field,r,record), _href=str(href))
                    elif field.represent:
                        r = represent(field,r,record)
                elif linkto and hasattr(field._table,'_primarykey') and fieldname in field._table._primarykey:
                    # have to test this with multi-key tables

key = urllib.urlencode(dict( [ \
                                ((tablename in record \
                                      and isinstance(record, Row) \
                                      and isinstance(record[tablename], Row)) and
                                 (k, record[tablename][k])) or (k, record[k]) \
                                    for k in field._table._primarykey ] ))
                    r = A(r, _href='%s/%s?%s' % (linkto, tablename, key))
                elif field.type.startswith('list:'):
                    r = represent(field,r or [],record)
                elif field.represent:
                    r = represent(field,r,record)
                elif field.type == 'blob' and r:
                    r = 'DATA'
                elif field.type == 'upload':
                    if upload and r:
                        r = A('file', _href='%s/%s' % (upload, r))
                    elif r:
                        r = 'file'
                    else:
                        r = ''
                elif field.type in ['string','text']:
                    r = str(field.formatter(r))
                    if headers!={}: #new implement dict
                        if isinstance(headers[colname],dict):
                            if isinstance(headers[colname]['truncate'], int):
                                r = truncate_string(r, headers[colname]['truncate'])
                    elif not truncate is None:
                        r = truncate_string(r, truncate)
                attrcol = dict()#new implement dict
                if headers!={}:
                    if isinstance(headers[colname],dict):
                        colclass=headers[colname]['class']

def gridbutton(buttonclass='buttonadd',buttontext='Add',
                       buttonurl=url(args=[]),callback=None,delete=None,trap=True):
            if showbuttontext:
                if callback:
                    return A(SPAN(_class=ui.get(buttonclass)),
                             SPAN(T(buttontext),_title=buttontext,
                                  _class=ui.get('buttontext')),
                             callback=callback,delete=delete,
                             _class=trap_class(ui.get('button'),trap))
                else:
                    return A(SPAN(_class=ui.get(buttonclass)),
                             SPAN(T(buttontext),_title=buttontext,
                                  _class=ui.get('buttontext')),
                             _href=buttonurl,
                             _class=trap_class(ui.get('button'),trap))
            else:
                if callback:
                    return A(SPAN(_class=ui.get(buttonclass)),
                             callback=callback,delete=delete,
                             _title=buttontext,
                             _class=trap_class(ui.get('buttontext'),trap))

callback=callback,delete=delete,
                             _class=trap_class(ui.get('button'),trap))
                else:
                    return A(SPAN(_class=ui.get(buttonclass)),
                             SPAN(T(buttontext),_title=buttontext,
                                  _class=ui.get('buttontext')),
                             _href=buttonurl,
                             _class=trap_class(ui.get('button'),trap))
            else:
                if callback:
                    return A(SPAN(_class=ui.get(buttonclass)),
                             callback=callback,delete=delete,
                             _title=buttontext,
                             _class=trap_class(ui.get('buttontext'),trap))
                else:
                    return A(SPAN(_class=ui.get(buttonclass)),
                             _href=buttonurl,_title=buttontext,
                             _class=trap_class(ui.get('buttontext'),trap))
        dbset = db(query)

)
        attr = UploadWidget._attributes(field, default, **attributes)

        inp = INPUT(**attr)

        if download_url and value:
            url = download_url + '/' + value
            (br, image) = ('', '')
            if UploadWidget.is_image(value):
                br = BR()
                image = IMG(_src = url, _width = UploadWidget.DEFAULT_WIDTH)

            requires = attr["requires"]
            if requires == [] or isinstance(requires, IS_EMPTY_OR):
                inp = DIV(inp, '[',
                          A(UploadWidget.GENERIC_DESCRIPTION, _href = url),
                          '|',
                          INPUT(_type='checkbox',
                                _name=field.name + UploadWidget.ID_DELETE_SUFFIX),
                          UploadWidget.DELETE_FILE,
                          ']', br, image)
            else:
                inp = DIV(inp, '[',
                          A(UploadWidget.GENERIC_DESCRIPTION, _href = url),
                          ']', br, image)
        return inp

key = urllib.urlencode(dict( [ \
                                ((tablename in record \
                                      and isinstance(record, Row) \
                                      and isinstance(record[tablename], Row)) and
                                 (k, record[tablename][k])) or (k, record[k]) \
                                    for k in field._table._primarykey ] ))
                    r = A(r, _href='%s/%s?%s' % (linkto, tablename, key))
                elif field.type.startswith('list:'):
                    r = field.represent(r or [])
                elif field.represent:
                    r = field.represent(r)
                elif field.type == 'blob' and r:
                    r = 'DATA'
                elif field.type == 'upload':
                    if upload and r:
                        r = A('file', _href='%s/%s' % (upload, r))
                    elif r:
                        r = 'file'
                    else:
                        r = ''
                elif field.type in ['string','text']:
                    r = str(field.formatter(r))
                    ur = unicode(r, 'utf8')
                    if truncate!=None and len(ur) > truncate:
                        r = ur[:truncate - 3].encode('utf8') + '...'
                row.append(TD(r))
            tbody.append(TR(_class=_class, *row))
        components.append(TBODY(*tbody))

if selectable:
            head.append(TH(_class=ui.get('default','')))
        for field in fields:
            if columns and not str(field) in columns: continue
            if not field.readable: continue
            key = str(field)
            header = headers.get(str(field),
                                 hasattr(field,'label') and field.label or key)
            if sortable:
                if key == order:
                    key, marker = '~'+order, sorter_icons[0]
                elif key == order[1:]:
                    marker = sorter_icons[1]
                else:
                    marker = ''
                header = A(header,marker,_href=url(vars=dict(
                            keywords=request.vars.keywords or '',
                            order=key)),_class=trap_class())
            head.append(TH(header, _class=ui.get('default','')))

        if links and links_in_grid:
            for link in links:
                if isinstance(link,dict):
                    head.append(TH(link['header'], _class=ui.get('default','')))

        # Include extra column for buttons if needed.
        include_buttons_column = (details or editable or deletable or
            (links and links_in_grid and
             not all([isinstance(link, dict) for link in links])))
        if include_buttons_column:
            head.append(TH(_class=ui.get('default','')))

def self_link(name,p):
                d = dict(page=p+1)
                if order: d['order']=order
                if request.vars.keywords: d['keywords']=request.vars.keywords
                return A(name,_href=url(vars=d),_class=trap_class())
            NPAGES = 5 # window is 2*NPAGES

image = IMG(_src = url, _width = cls.DEFAULT_WIDTH)

            requires = attr["requires"]
            if requires == [] or isinstance(requires, IS_EMPTY_OR):
                inp = DIV(inp, '[',
                          A(UploadWidget.GENERIC_DESCRIPTION, _href = url),
                          '|',
                          INPUT(_type='checkbox',
                                _name=field.name + cls.ID_DELETE_SUFFIX,
                                _id=field.name + cls.ID_DELETE_SUFFIX),
                                LABEL(cls.DELETE_FILE,
                                     _for=field.name + cls.ID_DELETE_SUFFIX),
                                ']', br, image)
            else:
                inp = DIV(inp, '[',
                          A(cls.GENERIC_DESCRIPTION, _href = url),
                          ']', br, image)
        return inp