recovering-deleted-wagtail-pages/slides.md

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title: Recovering deleted Wagtail pages and Django models
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# Recovering [deleted]{style="color: #fd5765"} Wagtail pages and/or Django models

### Jake Howard{style="color: #e85537;" .mt-10 }

<ul class="list-none! text-sm [&>li]:m-0! mt-1 uppercase">
  <li>Senior Systems Engineer @ Torchbox</li>
  <li>Core Team, Security Team & Performance Working Group @ Wagtail</li>
</ul>

<ul class="list-none! text-sm [&>li]:m-0! mt-3">
  <li><mdi-earth /> theorangeone.net</li>
  <li><mdi-twitter /> @RealOrangeOne</li>
  <li><mdi-github /> @RealOrangeOne</li>
  <li><mdi-mastodon /> @jake@theorangeone.net</li>
</ul>

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# Setting the scene

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# Site history report

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# Restoring from backups

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# _Partially_ restoring from backups

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## 1.
# Spin up a database backup

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## 2.
# Locate the page models

<div class="pt-5">

```python
from wagtail.models import Page

sysadmin_page = Page.objects.get(id=91)

child_pages = sysadmin_page.get_descendants()
```

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## 3.
# Locate what was deleted

<div class="pt-5">

```python
from django.contrib.admin.utils import NestedObjects

collector = NestedObjects()
collector.collect(list(child_pages) + [sysadmin_page])
```

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# 4. Serialize

<div class="pt-5">

```python {all|3-5|all}
from django.core import serializers

class NoM2MSerializer(Serializer):
    def handle_m2m_field(self, obj, field):
        pass

def get_model_instances():
    for qs in collector.data.values():
        yield from qs

with open("deleted-models.json", "w") as f:
    NoM2MSerializer().serialize(
        get_model_instances(),
        stream=f
    )
```

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## 4a.
# [De]{.italic}serialize

### `manage.py loaddata`

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# `restore-deleted-pages.py`

```python {all}{lines:true}
from django.contrib.admin.utils import NestedObjects
from django.core import serializers

from wagtail.models import Page

class NoM2MSerializer(Serializer):
    def handle_m2m_field(self, obj, field):
        pass

sysadmin_page = Page.objects.get(id=91)

child_pages = sysadmin_page.get_descendants()

collector = NestedObjects()
collector.collect(list(child_pages) + [sysadmin_page])

def get_model_instances():
    for qs in collector.data.values():
        yield from qs

with open("deleted-models.json", "w") as f:
    NoM2MSerializer().serialize(
        get_model_instances(),
        stream=f
    )
```

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### 5.
# **Test!**

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### 6.
# Showtime!

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1. Backup!
2. Transfer `deleted-models.json` to server
3. `loaddata`
4. `checktree`
5. `update_index`
6. `rebuild_reference_index`

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# Conclusion

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END

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