doctype-patterns

name	doctype-patterns
description	Frappe DocType creation patterns, field types, controller hooks, and data modeling best practices. Use when creating DocTypes, designing data models, adding fields, or setting up document relationships in Frappe/ERPNext.

Frappe DocType Patterns

Comprehensive guide to creating and configuring DocTypes in Frappe Framework, the core building block for all Frappe applications.

When to Use This Skill

• Creating new DocTypes
• Adding or modifying fields on DocTypes
• Designing data models and relationships
• Setting up naming patterns and autoname
• Configuring permissions and workflows
• Creating child tables
• Working with Virtual or Single DocTypes

DocType Directory Structure

When you create a DocType named "My Custom DocType" in module "My Module":

my_app/
└── my_module/
    └── doctype/
        └── my_custom_doctype/
            ├── my_custom_doctype.json      # DocType definition
            ├── my_custom_doctype.py        # Python controller
            ├── my_custom_doctype.js        # Client script
            ├── test_my_custom_doctype.py   # Test file
            └── __init__.py

DocType JSON Structure

{
  "name": "My Custom DocType",
  "module": "My Module",
  "doctype": "DocType",
  "engine": "InnoDB",
  "field_order": ["field1", "field2"],
  "fields": [
    {
      "fieldname": "field1",
      "fieldtype": "Data",
      "label": "Field 1",
      "reqd": 1
    }
  ],
  "permissions": [
    {
      "role": "System Manager",
      "read": 1,
      "write": 1,
      "create": 1,
      "delete": 1
    }
  ],
  "autoname": "naming_series:",
  "naming_rule": "By \"Naming Series\" field",
  "is_submittable": 0,
  "istable": 0,
  "issingle": 0,
  "track_changes": 1,
  "sort_field": "modified",
  "sort_order": "DESC"
}

Field Types Reference

Text Fields

Type	Description	Use Case
Data	Single line text (140 chars)	Names, codes, short text
Small Text	Multi-line text	Short descriptions
Text	Multi-line text (unlimited)	Long descriptions
Text Editor	Rich text with formatting	Content, notes
Code	Syntax-highlighted code	Python, JS, JSON
HTML Editor	WYSIWYG HTML	Email templates
Markdown Editor	Markdown input	Documentation
Password	Masked input	Secrets (stored encrypted)

Numeric Fields

Type	Description	Use Case
Int	Integer	Counts, quantities
Float	Decimal number	Measurements
Currency	Money with precision	Prices, amounts
Percent	0-100 percentage	Discounts, rates
Rating	Star rating (0-1)	Reviews, scores

Date/Time Fields

Type	Description	Use Case
Date	Date only	Birth dates, due dates
Datetime	Date and time	Timestamps
Time	Time only	Schedules
Duration	Time duration	Task duration

Selection Fields

Type	Description	Use Case
Select	Dropdown options	Status, type
Check	Boolean checkbox	Flags, toggles
Autocomplete	Text with suggestions	Tags

Link Fields

Type	Description	Use Case
Link	Reference to another DocType	Foreign key relationship
Dynamic Link	Reference based on another field	Polymorphic links
Table	Child table (1-to-many)	Line items, details
Table MultiSelect	Many-to-many via link	Multiple selections

Special Fields

Type	Description	Use Case
Attach	Single file attachment	Documents
Attach Image	Image with preview	Photos, logos
Image	Display image from URL field	Gallery
Signature	Signature pad	Approvals
Geolocation	Map coordinates	Locations
Barcode	Barcode/QR display	Inventory
JSON	JSON data	Configuration

Layout Fields

Type	Description	Use Case
Section Break	Horizontal section divider	Form organization
Column Break	Vertical column divider	Multi-column layout
Tab Break	Tab navigation	Large forms
HTML	Static HTML content	Instructions, headers
Heading	Section heading	Visual separation
Button	Clickable button	Actions

Field Options

Common Field Properties

{
  "fieldname": "customer",
  "fieldtype": "Link",
  "label": "Customer",
  "options": "Customer",
  "reqd": 1,
  "unique": 0,
  "in_list_view": 1,
  "in_standard_filter": 1,
  "in_global_search": 1,
  "bold": 1,
  "read_only": 0,
  "hidden": 0,
  "print_hide": 0,
  "no_copy": 0,
  "allow_in_quick_entry": 1,
  "translatable": 0,
  "default": "",
  "description": "Select the customer",
  "depends_on": "eval:doc.is_customer",
  "mandatory_depends_on": "eval:doc.status=='Active'",
  "read_only_depends_on": "eval:doc.docstatus==1"
}

Link Field Options

{
  "fieldname": "customer",
  "fieldtype": "Link",
  "options": "Customer",
  "filters": {
    "disabled": 0,
    "customer_type": "Company"
  },
  "ignore_user_permissions": 0
}

Select Field Options

{
  "fieldname": "status",
  "fieldtype": "Select",
  "options": "\nDraft\nPending\nApproved\nRejected",
  "default": "Draft"
}

Dynamic Link

{
  "fieldname": "party_type",
  "fieldtype": "Link",
  "options": "DocType"
},
{
  "fieldname": "party",
  "fieldtype": "Dynamic Link",
  "options": "party_type"
}

Naming Patterns (autoname)

Naming Series

{
  "autoname": "naming_series:",
  "naming_rule": "By \"Naming Series\" field"
}

Add a naming_series field:

{
  "fieldname": "naming_series",
  "fieldtype": "Select",
  "options": "INV-.YYYY.-\nINV-.MM.-.YYYY.-",
  "default": "INV-.YYYY.-"
}

Field-Based Naming

{
  "autoname": "field:customer_code",
  "naming_rule": "By fieldname"
}

Expression-Based

{
  "autoname": "format:{customer_type}-{###}",
  "naming_rule": "Expression"
}

Hash/Random

{
  "autoname": "hash",
  "naming_rule": "Random"
}

Prompt (Manual)

{
  "autoname": "Prompt",
  "naming_rule": "Set by user"
}

Controller Lifecycle Hooks

# my_doctype.py
import frappe
from frappe.model.document import Document

class MyDocType(Document):
    # ===== BEFORE DATABASE OPERATIONS =====

    def autoname(self):
        """Set the document name before saving"""
        self.name = f"{self.prefix}-{frappe.generate_hash()[:8]}"

    def before_naming(self):
        """Called before autoname, can modify naming logic"""
        pass

    def validate(self):
        """Validate data before save (called on insert and update)"""
        self.validate_dates()
        self.calculate_totals()

    def before_validate(self):
        """Called before validate"""
        pass

    def before_save(self):
        """Called before document is saved to database"""
        self.modified_by_script = True

    def before_insert(self):
        """Called before new document is inserted"""
        self.set_defaults()

    # ===== AFTER DATABASE OPERATIONS =====

    def after_insert(self):
        """Called after new document is inserted"""
        self.notify_users()

    def on_update(self):
        """Called after document is saved (insert or update)"""
        self.update_related_docs()

    def after_save(self):
        """Called after on_update, always runs"""
        pass

    def on_change(self):
        """Called when document changes in database"""
        pass

    # ===== SUBMISSION WORKFLOW =====

    def before_submit(self):
        """Called before document is submitted"""
        self.validate_for_submit()

    def on_submit(self):
        """Called after document is submitted"""
        self.create_gl_entries()

    def before_cancel(self):
        """Called before document is cancelled"""
        self.validate_cancellation()

    def on_cancel(self):
        """Called after document is cancelled"""
        self.reverse_gl_entries()

    def on_update_after_submit(self):
        """Called when submitted doc is updated (limited fields)"""
        pass

    # ===== DELETION =====

    def before_delete(self):
        """Called before document is deleted"""
        self.check_dependencies()

    def after_delete(self):
        """Called after document is deleted"""
        self.cleanup_attachments()

    def on_trash(self):
        """Called when document is trashed"""
        pass

    def after_restore(self):
        """Called after document is restored from trash"""
        pass

    # ===== CUSTOM METHODS =====

    def validate_dates(self):
        if self.end_date and self.start_date > self.end_date:
            frappe.throw("End date cannot be before start date")

    def calculate_totals(self):
        self.total = sum(d.amount for d in self.items)

Child Table (Table Field)

Parent DocType

{
  "fieldname": "items",
  "fieldtype": "Table",
  "label": "Items",
  "options": "My DocType Item",
  "reqd": 1
}

Child DocType JSON

{
  "name": "My DocType Item",
  "module": "My Module",
  "doctype": "DocType",
  "istable": 1,
  "editable_grid": 1,
  "fields": [
    {
      "fieldname": "item",
      "fieldtype": "Link",
      "options": "Item",
      "in_list_view": 1,
      "reqd": 1
    },
    {
      "fieldname": "qty",
      "fieldtype": "Float",
      "in_list_view": 1
    },
    {
      "fieldname": "rate",
      "fieldtype": "Currency",
      "in_list_view": 1
    },
    {
      "fieldname": "amount",
      "fieldtype": "Currency",
      "in_list_view": 1,
      "read_only": 1
    }
  ]
}

Single DocType (Settings)

For application settings that have only one record:

{
  "name": "My App Settings",
  "module": "My Module",
  "doctype": "DocType",
  "issingle": 1,
  "fields": [
    {
      "fieldname": "enable_feature",
      "fieldtype": "Check",
      "label": "Enable Feature"
    },
    {
      "fieldname": "api_key",
      "fieldtype": "Password",
      "label": "API Key"
    }
  ]
}

Access in code:

settings = frappe.get_single("My App Settings")
if settings.enable_feature:
    do_something()

Virtual DocType

DocType without database table, computed on-the-fly:

{
  "name": "My Virtual DocType",
  "module": "My Module",
  "doctype": "DocType",
  "is_virtual": 1
}

Controller:

class MyVirtualDocType(Document):
    @staticmethod
    def get_list(args):
        # Return list of virtual documents
        return [{"name": "doc1", "value": 100}]

    @staticmethod
    def get_count(args):
        return len(MyVirtualDocType.get_list(args))

    @staticmethod
    def get_stats(args):
        return {}

Permissions

{
  "permissions": [
    {
      "role": "System Manager",
      "read": 1,
      "write": 1,
      "create": 1,
      "delete": 1,
      "submit": 1,
      "cancel": 1,
      "amend": 1,
      "report": 1,
      "export": 1,
      "import": 1,
      "share": 1,
      "print": 1,
      "email": 1
    },
    {
      "role": "Sales User",
      "read": 1,
      "write": 1,
      "create": 1,
      "if_owner": 1
    }
  ]
}

Best Practices

Naming Conventions

• Use singular names: "Customer" not "Customers"
• Use Title Case with spaces: "Sales Invoice"
• Fieldnames use snake_case: customer_name

Field Design

• Put most important fields first
• Use Section Breaks to organize
• Use Tab Breaks for complex forms
• Set in_list_view for key fields
• Set in_standard_filter for filterable fields

Performance

• Index frequently queried fields with search_index: 1
• Use read_only to prevent unnecessary validation
• Limit child table rows with max_attachments

Data Integrity

• Use unique: 1 for unique constraints
• Set appropriate reqd (required) flags
• Use depends_on for conditional visibility
• Use mandatory_depends_on for conditional requirements

Common Patterns

Status Field Pattern

{
  "fieldname": "status",
  "fieldtype": "Select",
  "options": "\nDraft\nPending Approval\nApproved\nRejected",
  "default": "Draft",
  "in_list_view": 1,
  "in_standard_filter": 1,
  "read_only": 1,
  "allow_on_submit": 1
}

Amount Calculation Pattern

[
  {"fieldname": "qty", "fieldtype": "Float"},
  {"fieldname": "rate", "fieldtype": "Currency"},
  {"fieldname": "amount", "fieldtype": "Currency", "read_only": 1}
]

With controller:

def validate(self):
    for item in self.items:
        item.amount = flt(item.qty) * flt(item.rate)
    self.total = sum(item.amount for item in self.items)

Linked Document Pattern

{
  "fieldname": "customer",
  "fieldtype": "Link",
  "options": "Customer",
  "reqd": 1
},
{
  "fieldname": "customer_name",
  "fieldtype": "Data",
  "fetch_from": "customer.customer_name",
  "read_only": 1
}