Is there a way to set multiple database fields from one dropdown

[geckigek]

Hi there,

I am currently working on a ptp plugin for netbox. The data structure looks as follows:

class PTPProfilesChoices(ChoiceSet):

    CHOICES = [
        (0, 'SMPTE-2059-2'),
        (1, 'AES67'),
        (2, 'default'),
    ]

class PTPSyncIntChoices(ChoiceSet):

    CHOICES = [
        (-3, '8 per second'),
        (-2, '4 per second'),
        (-1, '2 per second'),
        (0, '1 per second'),
        (1, '1/2 per second'),
    ]

class PTPAnnounceIntChoices(ChoiceSet):

    CHOICES = [
        (-3, '8 per second'),
        (-2, '4 per second'),
        (-1, '2 per second'),
        (0, '1 per second'),
        (1, '1/2 per second'),
    ]

class PTPDelayReqIntChoices(ChoiceSet):

    CHOICES = [
        (-3, '8 per second'),
        (-2, '4 per second'),
        (-1, '2 per second'),
        (0, '1 per second'),
        (1, '1/2 per second'),
    ]

class PTPTemplate(NetBoxModel):

    name = models.CharField(
        max_length = 30
    )

    devicetype = models.OneToOneField(
        to = 'dcim.DeviceType',
        on_delete=models.CASCADE,
        blank = False,
    )

    ptp_enabled = models.BooleanField(
        default= False
    )

    mode = models.CharField(
        max_length = 30,
        choices = PTPModeChoices
    )

    ptp_domain = models.IntegerField(
        default = 0
    )

    log_ptp_sync_interval = models.IntegerField(
        default = -3,
        choices = PTPSyncIntChoices,
    )

    log_ptp_announce_interval = models.IntegerField(
        default = 0,
        choices = PTPAnnounceIntChoices,
    )

    log_ptp_delayreq_interval = models.IntegerField(
        default = 0,
        choices = PTPDelayReqIntChoices,

    ptp_profile = models.IntegerField(
        default = 0,
        choices = PTPProfilesChoices,
    )

So my requirement would be to set the value of ptp_profile in a rendered drop down menu and when I set hte ptp_profile value the values of log_ptp_sync_interval, log_ptp_announce_interval and log_ptp_delayreq_interval will automaticly set to a pre defined value from the ptp profile. For Example if ptp_profile would be 0 (SMPTE-2059-2) the three values should be set accordingly:

log_ptp_sync_interval = -3
log_ptp_announce_interval = 0
log_ptp_delayreq_interval = -3

Is this even possible and is there a way to achieve such a behavior?

Best regards

Stefan

[candlerb]

Aside: please can you edit your post and put three backticks (```) on a line of their own, before and after the code, to make it easier to read.

So my requirement would be to set the value of ptp_profile in a rendered drop down menu and when I set hte ptp_profile value the values of log_ptp_sync_interval, log_ptp_announce_interval and log_ptp_delayreq_interval will automaticly set to a pre defined value from the ptp profile.

If you want to do this in the model, you can just hook into the save() or clean() methods. There are plenty of examples of this in Netbox's own code. Maybe something like this outline:

class PTPTemplate(NetBoxModel):
    ...
    def save(self, *args, **kwargs):
        if self.log_ptp_sync_interval is None:
            self.log_ptp_sync_interval = ... choice based on self.ptp_profile ...
        if self.log_ptp_announce_interval is None:
            self.log_ptp_announce_interval = ... choice based on self.ptp_profile ...
        ... etc

        return super().save(*args, **kwargs)

(This approach would mean not setting an explicit default value of 0, and instead letting the None value propagate so that save() can detect when the user didn't make a selection. Or you could have a dummy default value like -32768 to indicate that no choice was made)

If you are talking about a form displayed on-screen, and you want a click on one selection menu to trigger updates to other selection menus, then that's harder - at that point you're messing about with Javascript.

[candlerb]

There is a concrete example of this in the Interface wifi attributes, in netbox/dcim/models/device_components.py

    rf_channel = models.CharField(
        max_length=50,
        choices=WirelessChannelChoices,
        blank=True,
        verbose_name=_('wireless channel')
    )
    rf_channel_frequency = models.DecimalField(
        max_digits=7,
        decimal_places=2,
        blank=True,
        null=True,
        verbose_name=_('channel frequency (MHz)'),
        help_text=_("Populated by selected channel (if set)")
    )
    rf_channel_width = models.DecimalField(
        max_digits=7,
        decimal_places=3,
        blank=True,
        null=True,
        verbose_name=('channel width (MHz)'),
        help_text=_("Populated by selected channel (if set)")
    )
...

    def save(self, *args, **kwargs):

        # Set absolute channel attributes from selected options
        if self.rf_channel and not self.rf_channel_frequency:
            self.rf_channel_frequency = get_channel_attr(self.rf_channel, 'frequency')
        if self.rf_channel and not self.rf_channel_width:
            self.rf_channel_width = get_channel_attr(self.rf_channel, 'width')

        super().save(*args, **kwargs)

[geckigek]

Thanks for your help @candlerb!

The example of yours worked out fine! Thank you!