Frappe Syntax Serverscripts

┌──────────────────────────────────────────────────────────────────┐
│  ALL import STATEMENTS ARE BLOCKED                               │
│                                                                  │
│  import json             → ImportError: __import__ not found     │
│  from datetime import *  → ImportError: __import__ not found     │
│  import frappe           → ImportError (even frappe itself!)     │
│                                                                  │
│  EVERYTHING you need is pre-loaded in the frappe namespace.      │
│  NEVER write an import line. ALWAYS use frappe.utils.*, etc.     │
└──────────────────────────────────────────────────────────────────┘

# v14: enabled by default
# v15+: DISABLED by default — you MUST enable explicitly:
bench set-config -g server_script_enabled 1
# Or set server_script_enabled: true in site_config.json

Need custom Python logic for a DocType?
│
├─► Can you install a custom Frappe app?
│   ├─► YES: Use a Document Controller when you need:
│   │   • import statements (any Python library)
│   │   • File system access
│   │   • Complex class inheritance
│   │   • autoname / before_naming hooks
│   │   • Unit-testable code
│   │
│   └─► NO: Use a Server Script when:
│       • You only have UI access (no bench CLI)
│       • Logic is simple validation / field calculation
│       • You need a quick API endpoint
│       • You need dynamic permission filtering
│
└─► Is logic > 50 lines or needs external libraries?
    ├─► YES → Document Controller in a custom app
    └─► NO  → Server Script is fine

doc                         # Current document (Document Event only)
frappe                      # Core namespace — ALWAYS available
frappe.db                   # Database operations
frappe.utils                # Date, number, string utilities
frappe.session              # Current session (user, csrf_token)
frappe.form_dict            # Request parameters (API scripts)
frappe.response             # Response object (API scripts)
frappe.request              # Werkzeug request object
frappe.qb                   # Query Builder (v14+)
json                        # Python json module (pre-loaded)

# Documents
frappe.get_doc(doctype, name)           # Fetch document
frappe.new_doc(doctype)                 # Create new document
frappe.get_cached_doc(doctype, name)    # Cached fetch (read-only)
frappe.get_last_doc(doctype)            # Most recent document
frappe.get_mapped_doc(...)              # Map fields between DocTypes
frappe.delete_doc(doctype, name)        # Delete document
frappe.rename_doc(doctype, old, new)    # Rename document

# Querying
frappe.get_all(doctype, filters, fields, order_by, limit)   # No permission check
frappe.get_list(doctype, filters, fields, order_by, limit)  # With permission check
frappe.db.get_value(doctype, name, fieldname)
frappe.db.get_single_value(doctype, fieldname)
frappe.db.set_value(doctype, name, fieldname, value)
frappe.db.exists(doctype, name_or_filters)
frappe.db.count(doctype, filters)
frappe.db.sql(query, values, as_dict)   # ALWAYS parameterize!
frappe.db.escape(value)                 # SQL escape
frappe.db.commit()                      # ONLY in Scheduler scripts
frappe.db.rollback()                    # ONLY in Scheduler scripts

# Messaging
frappe.throw(msg, exc, title)           # Stop execution + show error
frappe.msgprint(msg, title, indicator)  # User notification
frappe.log_error(message, title)        # Error Log entry

# HTTP (yes, these work in sandbox!)
frappe.make_get_request(url, params, headers)
frappe.make_post_request(url, data, headers)
frappe.make_put_request(url, data, headers)

# Email
frappe.sendmail(recipients, sender, subject, message)

# Utilities
frappe.utils.today()                    # "2024-01-15"
frappe.utils.now()                      # "2024-01-15 10:30:00"
frappe.utils.now_datetime()             # datetime object
frappe.utils.add_days(date, n)          # Date arithmetic
frappe.utils.add_months(date, n)
frappe.utils.date_diff(d1, d2)          # Days between dates
frappe.utils.flt(val)                   # Safe float (None → 0.0)
frappe.utils.cint(val)                  # Safe int (None → 0)
frappe.utils.cstr(val)                  # Safe string (None → "")
frappe.parse_json(string)               # JSON string → dict/list
frappe.as_json(obj)                     # dict/list → JSON string
frappe.render_template(template, ctx)   # Jinja rendering
frappe.get_url()                        # Site URL
frappe.get_hooks(hook)                  # Read app hooks
run_script(script_name, **kwargs)       # Call another Server Script

# Session / Permissions
frappe.session.user                     # Current user email
frappe.get_roles(user)                  # User's roles list
frappe.has_permission(doctype, ptype, doc)
frappe.get_fullname(user)               # User's display name
_("translatable string")               # Translation function

str, int, float, bool, list, dict, tuple, set  # Types
range, enumerate, zip, map, filter              # Iteration
sum, min, max, len, sorted, reversed            # Aggregation
isinstance, type, hasattr, getattr              # Introspection
all, any, abs, round, divmod                    # Math/logic
print                                           # → server log
True, False, None                               # Constants

open, file          # No file I/O
eval, exec, compile # No dynamic code execution
__import__          # No imports (this is the root cause)
globals, locals     # No scope introspection

# Config: Reference DocType = Sales Invoice, Event = Before Save
if doc.grand_total < 0:
    frappe.throw("Total MUST NOT be negative")

doc.requires_approval = 1 if doc.grand_total > 10000 else 0