RULE with conditional behaviour? - Mailing list pgsql-general

Hello all,
I've got two versions of the same question;
- The short version:
    As I understand it a rule cannot fire a trigger?

- And the long version:

What I am trying to do is this:

I have three tables and  a view on those tables ( see end of message if
the view below alone isn't enough info and you're in a helpful mood )

  CREATE VIEW field_label_locales AS
  -- [REFNAME: flabel_loc]
    SELECT
      field_labels.id AS field_label_id,
      field_labels.label,
      fields.id AS field_id,
      fields.identifier,
      locales.id AS locale_id,
      locales.iso639,
      locales.iso3166
    FROM
      field_labels
    RIGHT OUTER JOIN
      fields ON field_labels.field_id = fields.id
    RIGHT OUTER JOIN
      locales ON field_labels.locale_id = locales.id;

a select on this view looks like:

 field_label_id |     label      | field_id |   identifier   | locale_id
| iso639 | iso3166
----------------+----------------+----------+----------------+-----------+--------+---------
              1 | Naam Ontvanger |        2 | sender_address |         1
| nl     | NL
                |                |          |                |         2
| nl     | BE
              2 | Recipient Name |        2 | sender_address |         3
| en     | GB
                |                |          |                |         4
| en     | US
                |                |          |                |         5
| de     | DE


What I would like to be able to do is:

UPDATE field_label_locales SET label = 'Sender Name' WHERE locale_id = 1;

So; if field_label_id = NULL, I need to insert a record into
field_labels, else I need to update the record referenced in field_labels.

Can I do this with a rule on the view?
I've created a trigger which works just fine, but I can seem to fire a
trigger with a rule?

I could implement it some other way, but lazy as I am I thought I'd fire
off a mail to the list to see if I am missing something obvious.

Regards,
Rob


====
the relevant bits of the thre tables:

  CREATE TABLE locales (
    iso639         varchar(2) NOT NULL,   -- two character iso639
language code
    iso3166        varchar(2),            -- two character iso3166
country code
    lang_native    varchar(80) NOT NULL,  -- language name in native
language
    country_native varchar(80),           -- country name in native language
    fallback       boolean DEFAULT false, -- If set to true, this locale is
    id            bigserial,
    PRIMARY KEY(id),
    UNIQUE(iso639, iso3166)
  );

  CREATE TABLE fields (
    identifier    varchar(30),
    id            bigserial,
    PRIMARY KEY(id)
  );

  CREATE TABLE field_labels (
    label         varchar(100) NOT NULL,
    locale_id       bigint NOT NULL,
    field_id        bigint NOT NULL,
    FOREIGN KEY(locale_id) REFERENCES locales ON DELETE RESTRICT ON
UPDATE CASCADE,
    FOREIGN KEY(field_id) REFERENCES fields ON DELETE RESTRICT ON UPDATE
CASCADE
  );