You want to ensure a blog post's slug field is generated from its title only if the slug is empty, before saving. Which signal and method is the best practice?
hard📝 lifecycle Q8 of 15
Django - Signals
You want to ensure a blog post's slug field is generated from its title only if the slug is empty, before saving. Which signal and method is the best practice?
AOverride the model's <code>save()</code> method to set the slug unconditionally
BUse a <code>post_save</code> signal to update the slug after saving
CUse a <code>pre_save</code> signal to check if slug is empty and set it accordingly
DUse a <code>post_delete</code> signal to set the slug before saving
Step-by-Step Solution
Solution:
Step 1: Identify when to set slug
The slug should be set before saving, and only if empty.
Step 2: Choose appropriate signal
pre_save allows modifying fields before the database save.
Step 3: Avoid post_save and post_delete
Post_save runs after saving, which may cause extra saves; post_delete is unrelated.
Step 4: Overriding save() is possible but less decoupled than signals
Signals keep logic separate and reusable.
Final Answer:
Use a pre_save signal to check if slug is empty and set it accordingly -> Option C
Quick Check:
Pre_save modifies fields before saving [OK]
Quick Trick:Set slug in pre_save only if empty [OK]
Common Mistakes:
MISTAKES
Using post_save causing multiple saves
Overwriting slug unconditionally in save()
Using unrelated signals like post_delete
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