Frappe Errors Hooks

IS YOUR HOOK NOT FIRING?
│
├─► Check 1: Is the dotted path correct?
│   hooks.py: "myapp.events.sales.validate"
│   File:     myapp/events/sales.py → def validate(doc, method=None):
│   COMMON MISTAKE: "myapp.events.sales_invoice.validate" when file is sales.py
│
├─► Check 2: Is the dict structure correct?
│   doc_events uses NESTED dict: {"Sales Invoice": {"validate": "path"}}
│   scheduler_events uses LIST: {"daily": ["path1", "path2"]}
│   permission_query uses FLAT dict: {"Sales Invoice": "path"}
│
├─► Check 3: Is bench restarted after hooks.py change?
│   ALWAYS run: bench restart (or bench clear-cache for dev)
│
├─► Check 4: Is the DocType name exact?
│   "Sales Invoice" NOT "SalesInvoice" NOT "sales_invoice"
│   Use exact DocType name as shown in Frappe UI
│
└─► Check 5: Is the app installed on the site?
    bench --site mysite list-apps

# ❌ CAUSES ImportError — circular dependency
# myapp/hooks.py imports from myapp.events
# myapp/events/sales.py imports from myapp.hooks

# ✅ CORRECT — break the cycle
# Move shared constants to myapp/constants.py
# Import from constants in both hooks.py and events/

# ❌ WRONG — doc_events needs nested dict, not flat
doc_events = {
    "Sales Invoice": "myapp.events.validate"  # WRONG: string, not dict
}

# ✅ CORRECT
doc_events = {
    "Sales Invoice": {
        "validate": "myapp.events.sales.validate"
    }
}

# ❌ WRONG — scheduler_events daily needs list
scheduler_events = {
    "daily": "myapp.tasks.daily_sync"  # WRONG: string, not list
}

# ✅ CORRECT
scheduler_events = {
    "daily": ["myapp.tasks.daily_sync"]
}

# ❌ WRONG — cron needs nested dict with list values
scheduler_events = {
    "cron": ["0 9 * * *", "myapp.tasks.morning"]  # WRONG structure
}

# ✅ CORRECT
scheduler_events = {
    "cron": {
        "0 9 * * 1-5": ["myapp.tasks.morning_report"]
    }
}

# ❌ WRONG — missing assets/ prefix
app_include_js = "js/myapp.js"

# ❌ WRONG — using Python module path instead of file path
app_include_js = "myapp.public.js.myapp"

# ✅ CORRECT — full asset path
app_include_js = "assets/myapp/js/myapp.js"

# ✅ CORRECT — multiple files as list
app_include_js = ["assets/myapp/js/app.js", "assets/myapp/js/utils.js"]
app_include_css = "assets/myapp/css/myapp.css"

# Step 1: Is scheduler enabled?
bench scheduler status
# If disabled: bench scheduler enable

# Step 2: Are workers running?
bench doctor
# Look for: "Workers online: X"
# If 0: bench start (dev) or supervisorctl restart all (prod)

# Step 3: Check Scheduled Job Log
# In Frappe UI: /api/method/frappe.client.get_list?doctype=Scheduled Job Log&limit=5

# Step 4: Check Error Log for task failures
# In Frappe UI: /app/error-log

# Step 5: Is the task registered?
bench execute frappe.utils.scheduler.get_all_tasks

# ❌ PROBLEM: Task runs but changes not persisted
def daily_sync():
    for item in frappe.get_all("Item", limit=100):
        frappe.db.set_value("Item", item.name, "synced", 1)
    # MISSING: frappe.db.commit() — ALL changes lost!

# ✅ FIX: ALWAYS commit in scheduler tasks
def daily_sync():
    for item in frappe.get_all("Item", limit=100):
        frappe.db.set_value("Item", item.name, "synced", 1)
    frappe.db.commit()

# ❌ PROBLEM: Task fails silently — no debugging possible
def daily_task():
    try:
        process_records()
    except Exception:
        pass  # Silent death

# ✅ FIX: ALWAYS log errors in scheduler
def daily_task():
    try:
        process_records()
        frappe.db.commit()
    except Exception:
        frappe.log_error(frappe.get_traceback(), "Daily Task Error")

# If App A and App B both register validate for Sales Invoice:
# App A's handler throws → App B's handler NEVER runs

# ✅ ALWAYS be aware: your handler is not alone
def validate(doc, method=None):
    """Collect errors, throw once at end."""
    errors = []
    if doc.grand_total < 0:
        errors.append(_("Total cannot be negative"))
    if errors:
        frappe.throw("<br>".join(errors))

# ✅ For on_update: isolate independent operations
def on_update(doc, method=None):
    try:
        send_notification(doc)
    except Exception:
        frappe.log_error(frappe.get_traceback(), f"Notify error: {doc.name}")
    try:
        sync_external(doc)
    except Exception:
        frappe.log_error(frappe.get_traceback(), f"Sync error: {doc.name}")

# ❌ BREAKS transaction management
def on_update(doc, method=None):
    frappe.db.set_value("Counter", "main", "count", 100)
    frappe.db.commit()  # Partial commit — dangerous!

# ✅ Framework handles commits automatically
def on_update(doc, method=None):
    frappe.db.set_value("Counter", "main", "count", 100)

# ❌ BREAKS list view entirely
def query_conditions(user):
    if "Sales User" not in frappe.get_roles(user):
        frappe.throw("Access denied")  # LIST VIEW CRASHES
    return f"owner = '{user}'"  # Also: SQL injection!

# ✅ CORRECT — safe fallback, escaped values
def query_conditions(user):
    try:
        user = user or frappe.session.user
        if "System Manager" in frappe.get_roles(user):
            return ""
        return f"`tabSales Invoice`.owner = {frappe.db.escape(user)}"
    except Exception:
        frappe.log_error(frappe.get_traceback(), "Query Conditions Error")
        return f"`tabSales Invoice`.owner = {frappe.db.escape(frappe.session.user)}"

# ❌ BREAKS document access
def has_permission(doc, user=None, permission_type=None):
    if doc.status == "Locked":
        frappe.throw("Locked")  # DOCUMENT INACCESSIBLE

# ✅ Return False to deny, None to defer
def has_permission(doc, user=None, permission_type=None):
    try:
        user = user or frappe.session.user
        if doc.status == "Locked" and permission_type == "write":
            return False
        return None  # Defer to default permission system
    except Exception:
        frappe.log_error(frappe.get_traceback(), "Permission Error")
        return None

# ❌ COMMON: Import path changes between ERPNext versions
# v14 path:
override_doctype_class = {
    "Sales Invoice": "myapp.overrides.CustomSI"
}
# myapp/overrides.py:
from erpnext.accounts.doctype.sales_invoice.sales_invoice import SalesInvoice
# This path may change in v15/v16!

# ✅ ALWAYS call super(), re-raise validation errors
class CustomSalesInvoice(SalesInvoice):
    def validate(self):
        try:
            super().validate()
        except frappe.ValidationError:
            raise  # ALWAYS re-raise validation errors
        except Exception:
            frappe.log_error(frappe.get_traceback(), "Parent validate error")
            raise
        self.custom_validation()