id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
16433	Missing 'help_text' in admin form when showing the back reference for a OneToOne field.	chris@…	nobody	"I'm receiving the following exception in the admin pages for a particular construct:


{{{
Caught AttributeError while rendering: 'RelatedObject' object has no attribute 'help_text'
}}}


Here's the pastebin for the full exception: http://dpaste.com/564587/

The problem, I believe, is that help_text is missing for the admin screens when attempting to show a ""read only"" field of an object that was automatically generated from a OneToOneField.

Here's a reduced form of the models and admin pages that cause the error. The application is an art show management software, that has artists, pieces, invoices, and a class called ""invoice item"" that will attach a piece to an invoice with a price associated. A piece doesnt have a ""sale price"" until it gets attached to an invoice, a piece can only be on one invoice, but an invoice can have many pieces:


{{{
class Piece ( models.Model ):
    # most detail omitted
    name = models.CharField ( max_length = 100 )

class Invoice ( models.Model ):
    # most detail omitted
    total_paid = models.DecimalField ( max_digits=7, decimal_places=2, blank=True, null=True )

class InvoiceItem ( models.Model ):
    piece = models.OneToOneField ( Piece )
    invoice = models.ForeignKey ( Invoice )
    price = models.DecimalField ( max_digits=7, decimal_places=2 )
    def __unicode__ ( self ):
        return ""%s for $%s"" % ( self.invoice, self.price )
}}}


then in admin.py:


{{{
class PieceAdmin ( admin.ModelAdmin ):
    # most detail omitted
    fields = ( 'artist', 'pieceid', 'name', 'location', 'not_for_sale', 'adult', 'min_bid', 'buy_now', 'voice_auction', 'bidsheet_scanned', 'status', 'top_bid', 'invoiceitem' )
    readonly_fields = ( 'top_bid', 'invoiceitem' )
}}}


Most of the ""fields"" relate to fields that were omitted in the models above, or are methods of the PieceAdmin class. Of note is the 'invoiceitem' field. This is a field automatically generated for a Piece because of the OneToOneField field on InvoiceItem. Having this as a ""readonly_fields"" makes it available to the model (that seems to be a requirement), however, the presence of this at all generates the above exception. This code _did_ work in 1.3. I suspect that help_text is new for 1.4, but not all possible combinations of this or that have had the help_text added. The above is a bit of a corner-case, I know :)

I can probably work around this bug by creating an invoiceitem method (in much the same way I created a top_bid method).




"	Bug	closed	contrib.admin	dev	Normal	fixed		admackin+django@… net147 Francis Devereux	Accepted	1	0	0	0	0	0