Django how to use post_save signals

Question

I had learn about django signals but, I don't known where to implement in my project and how to use it in my project. In my project I want send email alerts if it matches to some particular criteria. In this case I need use post_save signals.I added the code with this. Kindly share your ideas.

models.py

class Personal(models.Model):
    user = models.OneToOneField(User)
    email = models.EmailField(max_length=100, blank=True, null=True)
    country = models.CharField(max_length=100, blank=True, null=True)
    state = models.CharField(max_length=100, blank=True, null=True)
    city = models.CharField(max_length=100, blank=True, null=True)

class Skills(models.Model):
    user = models.ForeignKey(User)
    skill = models.CharField(max_length=100, blank=True, null=True)

class jobs(models.Model):
    emp = models.ForeignKey(User, unique=False)
    title = models.CharField(max_length=100)
    industry = models.CharField(max_length=100)
    functionalarea = models.CharField(max_length=100)
    min_exp = models.IntegerField(default=0)
    max_exp = models.IntegerField(default=0)
    city = models.CharField(max_length=100)
    state = models.CharField(max_length=100)
    country = models.CharField(max_length=100)
    empskills = models.CharField(max_length=100, blank=True, null=True)

Here I want to match city and empskills of jobs table with personal.city and Skills.skill model. This event occurs every job posting if it matches any one field it will send mail to personal.email automatically. Please give sample one where and how to use the signal.

Answer 1

Write a function outside the model that handles when a new job is posted and finds the people to email.

You then specify Job as the sender for a post_save signal and connect the function.

from django.db.models.signals import post_save
from django.dispatch import receiver

@receiver(post_save, sender=Job)
def handle_new_job(sender, **kwargs):
    job = kwargs.get('instance')
    logger.info("POST_SAVE : Job : %s" % job)
    # find people to email based on `job` instance

Answer 2

This is an example of how to use post_save

from django.db.models.signals import post_save
from .models import MyModel

def my_handler(**kwargs):
    if kwargs[’raw’]:
        return
    ...
    # here you could return your mails 
post_save.connect(my_handler, sender=MyModel)

Hope this could help you !