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POManyToMany field not saved when using Django admin
 

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    <p>I'm experiencing a weird problem which I hope someone in here may be able to shed some light on.</p> <p>I'm overriding the save() method of a model to add some values to a ManyToMany-field after running super(). My problem is that when I'm saving in Django admin the values seems to get added to the relationship but is then empty again.</p> <p>If however I do it from <code>manage.py shell</code> it works without problem.</p> <p>I've put two print statements in there and they produce the exact same output regardless of if I'm running it via Django admin or via shell.</p> <pre><code>class Store(models.Model): holidays = models.ManyToManyField(StoreHoliday, blank=True) copy_holidays_from = models.ForeignKey('Store', blank=True, null=True) def save(self): print '==== BEFORE SAVE:', self.holidays.all() super(Store, self).save() self.copy_holidays() print '==== AFTER SAVE:', self.holidays.all() def copy_holidays(self): if self.pk and self.copy_holidays_from: self.holidays.clear() for h in self.copy_holidays_from.holidays.all(): self.holidays.add( h ) </code></pre> <p>This is the output of the <code>print</code> statements:</p> <pre><code>==== BEFORE SAVE: [] ==== AFTER SAVE: [&lt;StoreHoliday: 10 Mar 2010, Chuck Norris birthday (Closed)&gt;] </code></pre> <p>Does anyone have any suggestions on what might be causing this? </p> <p><strong>Edit:</strong> All manual changes to the m2m relationship in save() seems to be discarded by Django when saving through the admin interface. Is this related to how it processes the form?</p>
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    1. COI don't know where's your problem, but `self.holidays = self.copy_holidays_from.holidays.all()` looks much nicer then clearing and iterating.
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    2. COThank you for the tip, I didn't know that was possible. You can see below what I did wrong.
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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