django-salesforce 3.1

a Salesforce backend for Django's ORM

This library allows you to load, edit and query the objects in any Salesforce instance using Django models. The integration is fairly complete, and generally seamless for most uses. It works by integrating with the Django ORM, allowing access to the objects in your SFDC instance (Salesforce .com) as if they were in a traditional database.

Python 3.5.3 to 3.8, Django 1.11 to 3.1. (Tested also with Python 3.9.0b4)

Quick Start

Install, configure a Salesforce connection, create a Salesforce model and run.

1. Install django-salesforce: pip install django-salesforce

2. Add a salesforce connection to your DATABASES setting:

   'salesforce': {
       'ENGINE': 'salesforce.backend',
       'CONSUMER_KEY': '',                # 'client_id'   in OAuth2 terminology
       'CONSUMER_SECRET': '',             # 'client_secret'
       'USER': '',
       'PASSWORD': '',
       'HOST': 'https://test.salesforce.com',
   }

   In the example above, all fields should be populated as follows:

   • CONSUMER_KEY and CONSUMER_SECRET values are for the app used to connect to your Salesforce account. Instructions for how get these are in the Salesforce REST API Documentation. Key and secret can be created on web by:

     • Salesforce web > Setup > App Setup > Create > Apps > Connected apps > New.

     • Click “Enable OAuth Settings” in API, then select “Access and manage your data (api)” from available OAuth Scopes.

     • Other red marked fields must be filled, but are not relevant for Django with password authentication. (“Callback URL” should be a safe URL that maybe doesn’t exist, but is under your control and doesn’t redirect, for the case that you accidentally activate other OAuth mode later.)

   • USER is the username used to connect.

   • PASSWORD is a concatenation of the user’s password and security token. Security token can be set by My Settings / Personal / Reset My Security Token or an new token is received by email after every password change. Security token can be omitted if the local IP address has been whitelisted in Security Controls / Network Access.

   • HOST is https://test.salesforce.com to access a sandbox, or https://login.salesforce.com to access production.

   If an error occurs in a request to Salesforce, review the received error message that is exactly copied between braces {...} from the Salesforce response to a Python exception to assist debugging.

   See also: Information on settings up Salesforce connected apps if necessary.

   Note about permissions: Administrator rights are only required to run the full suite of unit tests; otherwise, as long as the account has rights to read or modify the chosen object, everything should work properly. Introspection by inspectdb doesn’t require any object permissions.

3. Add salesforce.router.ModelRouter to your DATABASE_ROUTERS setting:

   DATABASE_ROUTERS = [
       "salesforce.router.ModelRouter"
   ]

   (This is important for switching between ‘salesforce’ database for models derived from SalesforceModel and ‘default’ database for normal models with tables created by migrations, especially for ‘django.contrib’.)

4. Add the salesforce app to your INSTALLED_APPS setting:

   INSTALLED_APPS = {
       "django.contrib.auth",
       "django.contrib.contenttypes",
       ...
       ...
       "salesforce"
   }

   (This is necessary for running Salesforce extensions in the command inspectdb --database=salesforce in development, otherwise it is not important.)

5. Define a model that extends salesforce.models.Model (alias SalesforceModel) or export the complete SF schema by python manage.py inspectdb --database=salesforce and simplify it to what you need. The full models file is about 2 MB with 500 models and the export takes 2 minutes, but it is a valid models module that works without modification. The output of command inspectdb can be restricted by a list of table_names on the command line, but also ForeignKey fields to omitted models must be pruned to get a valid complete small model.

6. (optional) To override the default timeout of 15 seconds, define SALESFORCE_QUERY_TIMEOUT in your settings file. It can be one number or better a tuple with a short value for connection timeout and a longer value that includes time for running a query. It never need be longer than 30 seconds:

   SALESFORCE_QUERY_TIMEOUT = (4, 15)  # default (connect timeout, data timeout)

7. (optional) If you want to use another name for your Salesforce DB connection, define SALESFORCE_DB_ALIAS in your settings file:

   SALESFORCE_DB_ALIAS = 'salesforce'  # default

8. You’re all done! Just use your model like a normal Django model.

9. (optional) Create a normal Django admin.py module for your Salesforce models and you can register a minimalistic admin for all omitted Admin classes:

   from salesforce.testrunner.example.universal_admin import register_omitted_classes
   # some admin classes that you wrote manually yet
   # ...
   # end of file
   register_omitted_classes(your_application.models)

   This is a rudimentary way to verify that every model works in a sandbox, before hand-writing all admin classes. (Foreign keys to huge tables in the production require a customized admin e.g. with search widgets.)

10. (optional) By default, the Django ORM connects to all DBs at startup. To delay SFDC connections until they are actually required, define SF_LAZY_CONNECT=True in your settings file. Be careful when using this setting; since it won’t fail during the application boot, it’s possible for a bad password to be sent repeatedly, requiring an account reset to fix.

Primary Key

Salesforce doesn’t allow you to define custom primary keys, so django-salesforce will add them automatically in all cases. You can override only capitalization and use a primary key Id by configuring SF_PK='Id' in your project settings if you prefer Salesforce capitalized field name conventions instead of Django default id.

Advanced usage

• Multiple Inheritance from Abstract Models - Many Salesforce models use the same sets of fields, but using a single inheritance tree would be too complicated and fragile. Proxy models and mixins are also supported.

• Testing - By default, tests will be run against the SFDC connection specified in settings.py, which will substantially increase testing time.

  One way to speed this up is to change the SALESFORCE_DB_ALIAS to point to another DB connection (preferably SQLite) during testing using the TEST settings variable. Such simple tests can run without any network access. Django unit tests without SalesforceModel are fast everytimes. Special read only fields that are updated only by SFDC e.g. last_modified_date need more parameters to be possible to save them into an alternate database, e.g. by auto_now=True or to play with null=True or default=....

• Multiple SFDC connections - In most cases, a single connection is all that most apps require, so the default DB connection to use for Salesforce is defined by the SALESFORCE_DB_ALIAS settings variable. This behavior can be also configured by DATABASE_ROUTERS, replacing the use of salesforce.router.ModelRouter.

• Non SF databases - If SALESFORCE_DB_ALIAS is set to a conventional database, the tables defined by the SF models will be created by migrate. This behavior can be disabled by adding a Meta class with managed=False.

• Custom Managers - When creating a custom manager for a model, the manager must be a descendant of salesforce.manager.SalesforceManager.

  In most cases, switching DB connections with .using(alias). will be sufficient, but if you need to call a method on your custom manager, you should instead use .db_manager(alias) to select a DB while returning the correct manager, e.g. Contact.objects.db_manager(alias).my_manager(params...)

• Automatic Field Naming - Most of database columns names can be automatically deduced from Django field name, if no db_column is specified:

  last_name = models.CharField(max_length=80)     # db_column='LastName'
  FirstName = models.CharField(max_length=80)     # db_column='FirstName'
  my_bool = models.BooleanField(custom=True)      # db_column='MyBool__c'

  Fields named with an upper case character are never modified, except for the addition of the namespace prefix or the ‘__c’ suffix for custom fields. If you want models with minimal db_column then read Running inspectdb.

• Query deleted objects - Deleted objects that are in trash bin are not selected by a normal queryset, but if a special method query_all is used then also deleted objects are searched. If a trash bin is supported by the model then a boolean field IsDeleted can be in the model and it is possible to select only deleted objects

  deleted_list = list(Lead.objects.filter(IsDeleted=True).query_all())

• Migrations - Migrations can be used for an alternate test database with SalesforceModel. Then all tables must have Meta options db_table and fields must have option db_column, which is done by inspectdb with default settings. Models exported by introspection inspectdb do not specify the option managed because the default value is True. (It is safe. Migrations in SFDC are not supported. If anything would be implemented after all, only explicitly clearly selected fields and models could be migrated in explicitly labeled SFDC databases. Consequently, the setting managed = True is related only to an alternate non SFDC database configured by SALESFORCE_DB_ALIAS.)

• Exceptions - Custom exceptions instead of standard Django database exceptions are raised by Django-Salesforce to get more useful information. General exceptions are SalesforceError or a more general custom DatabaseError. They can be imported from salesforce.dbapi.exceptions if database errors should be handled specifically in your app.

Foreign Key Support

Foreign key relationships should work as expected, but mapping Salesforce SOQL to a purely-relational mapper is a leaky abstraction. For the gory details, see Foreign Key Support on the Django-Salesforce wiki.

Introspection and special attributes of fields

Some Salesforce fields can not be fully used without special attributes, namely read-only and default value fields. Further details can be found in Introspection and Special Attributes of Fields

Caveats

The ultimate goal of development of this package is to support reasonable new features of the Salesforce platform and of new Django versions, but for now here are the potential pitfalls and unimplemented operations:

• Large Objects — Since the entire result set needs to be transferred over HTTP, and since it’s common to have extremely high column counts on full object queries, it’s assumed that users will create models that are specific to their individual applications’ needs. It is especially important if migrations should be created. Migrations on the full models module are really slow. (Models that have been included with this library are very simplified only for example and documentation purposes and for tests.)

• Inheritance — When using the default router, all models Salesforce must extend salesforce.models.SalesforceModel. The model router checks for this to determine which models to handle through the Salesforce connection.

• Database Migrations — migrate will create new tables only in non-SF databases (useful for unit tests); SFDC tables are assumed to already exist with the appropriate permissions.

• Unsupported methods: Queryset methods union(), difference(),

  intersection() and distinct() are e.g. not supported because SOQL doesn’t support corresponding operators: UNION, EXCEPT, INTERSECT and DISTINCT.

Backwards-incompatible changes

The most important: - v0.9: This is the last version that suports Django 1.10 and Python 2.7 and 3.4

• v0.8: The default Meta option if now managed = True, which is an important change for non-Salesforce databases (see about Migrations above).

  Completely different implementation of raw queries and cursor that is compatible with normal databases. (a more backward compatible option can be added if it will be required)

  Custom exception classes has been moved to salesforce.dbapi.exceptions.

• v0.7.2: This is the last code that supports old Django 1.8.4+ and 1.9

• v0.6.9: This is the last code that supports old Django 1.7 and 1.8.0 - 1.8.3

• v0.6.1: This is the last code that supports old Django 1.4, 1.5, 1.6.

• v0.5: The name of primary key is currently 'id'. The backward compatible behavior for code created before v0.5 can be reached by settings SF_PK='Id'.