draup-django 1.0.0

Django Utility - Draup Labs

draup_django

Delete, Update functionality for normalised models

Use-Case :

• Draup Django provide delete, update functionality for ORM(object relational mapping)level.

Table of Content :

• Stateful Delete/Update
  • Get Affected Objects
  • Delete Object
  • Update Object
• Installation

Stateful Delete/Update

• Below are functions inorder to get the stateful delete/update

Get Affected Objects

• List out all dependent objects(Prompt-Messages).
• getAffectedObjects takes input dict with id as key and reference of model.

Sample Input : ({'id':1},model_reference)
Output : Error_list(list),prompt messages(list)

Delete Object

• Delete object with all the dependent objects.
• deleteObject takes input dict with id and force_delete as key and reference of model.

Sample Input : ({'id':1,'force_delete':True},model_reference)
Output : Error_list(list)

Update Object

• Transferring Object dependencies from one object to another object.
• updateObjectDependencies takes input source,destination objects.

Sample Input : (source,destination)
Output : Error_list(list)

Installation

• Use Pip to install the module

  pip install draup-django
  

Usage :

• Sample model :

    class parent(models.Model):
      name = models.CharField(max_length=100)
  
    class child(models.Model):
      parent = models.ForeignKey(parent, on_delete=models.CASCADE) 
      name = models.CharField(max_length=100)
  

• Parent Table :

  id	Name
  1	Alice
  2	Tom

• Child Table :

  id	Name	parent_id
  1	Bob	1
  2	Jack	2

• Code :

   from draup_django import utility
   m = models.parent
  
   """
   Get Prompt Message
   """
  
   error_list,prompt_message = utility.getAffectedObjects({'id':1},m)
  
   """
   Deletion with all dependent objects
   """
   error_list = utility.deleteObject({'id':1,'force_delete':True},m)
  
   """
   Transferring Object dependencies
   """
  
   source = m.objects.filter(id=1).first()
   destination = m.objects.filter(id=2).first()
   error_list = utility.updateObjectDependencies(source,destination)
  

• Output : Prompt Message of getAffectedObjects function

  [{'message': 'This object has been used in child 1 times.', 'model_name': 'child', 'Parent models': '', 'count': 1}] 
  

• Note :

  • Every function returns the error_list, and hence only the operation is successful only if it is empty.

  • According to above Child/Parent Table updateObjectDependencies function will transafer object dependency from id:1 to id:2 so parent_id of Bob will become 2.

  • Updated Child Table:

    id	Name	parent_id
    1	Bob	2
    2	Jack	2

Limitation :

• updateObjectDependencies will not work in case of unique constraint,one to one field in model.
• Please feel free to share your thoughts and feedback at [e-mail] .