Automate your backend with no code — A guide to using server scripts

Have you implemented ERPNext, but found it inconvenient to have to register both users and employees twice? This article explains how to automatically generate an Employee when creating a User using a Server Script.

Introduction

ERPNext comes standard with the following 5 customization options:

• Custom fields
• Custom Form
• Client script
• Server script
• App

It can be expanded in stages according to the application, and adjustments can be made to suit the specific needs of the site.

This article focuses on server scripts that allow you to change backend processing in a lightweight and flexible way. I will explain how to use it in practice.

This time, we will explain how to automatically generate an Employee at the same time as creating a User.

This can be achieved using only ERPNext's standard Server Script functionality and a short piece of Python code, without needing to create an external application.

Furthermore, ERPNext features separation of core and custom components and extension design using official Hooks/APIs, This allows for "robust customization" that is resilient to updates. (See separate article for details) Unbreakable customization , Client script Please see below.

So, let's start by experiencing server scripts with a minimal configuration and gradually expand our understanding.

What is a Server Script?

A Server Script is a mechanism for embedding small processes that run on the server side (Python) of ERPNext.

The concept is similar to Salesforce Apex triggers or kintone Webhooks + server functions. You can hook into document events to trigger automated processes and interactions.

Internally, you can access the frappe API (database access, document manipulation, message output, etc.), You can instantly implement "small-scale automation" without having to create a custom app.

While client-side scripts are responsible for UI improvements, Server scripts are responsible for automating business logic and controlling the backend.

for example

• Document Event Handling

• When a User is created, an Employee is automatically created as well.

• Once the sales invoice is confirmed, the inventory will be deducted.

• Scheduled Batch

• Send nightly invoice reminders

• Automatic notification of outstanding tasks

• API Endpoint

• Simple webhook that can be called from external services

• Add a custom REST endpoint

• Permission control and verification

• Check your own business rules before saving.

• Returns an error if the conditions are not met.

etc.
Lightweight extensions are possible that allow you to securely insert processes that don't require separate applications into the ERPNext core.

Implementation Steps

Now, let's actually register the server script.

Here, we will implement a minimal configuration where "when a user is created, an employee record is automatically created as well."

procedure

1. Go to Settings → Customize → Server Scripts

2. Create New → Set the following:

• Doctype:ユーザ
• Script Type:DocType Event
• Event:挿入後

3. Paste the code below → Save

# Website User は対象外
def split_first_last(name):
    name = (name or "").strip()
    if not name:
        return {"first": "", "last": ""}
    p = name.find(" ")
    if p == -1:
        return {"first": name, "last": ""}
    return {"first": name[:p], "last": name[p+1:]}
 
# ループ防止
if not frappe.flags.get("sync_user_employee_in_progress"):
 
    u = doc  # User
 
    # Website User は対象外（必要ならこの条件を外す）
    if u.user_type != "Website User":
 
        # 既に user_id で紐づいた Employee があれば何もしない
        if not frappe.db.exists("Employee", {"user_id": u.name}):
 
            # メール一致で既存Employeeを探索
            employee_name = None
            if u.email:
                employee_name = (
                    frappe.db.get_value("Employee", {"company_email": u.email}, "name")
                    or frappe.db.get_value("Employee", {"personal_email": u.email}, "name")
                )
 
            frappe.flags["sync_user_employee_in_progress"] = True
            try:
                if employee_name:
                    emp = frappe.get_doc("Employee", employee_name)
                    if not emp.user_id:
                        emp.db_set("user_id", u.name, update_modified=True)
                else:
                    # ここでタプルアンパックを使わない
                    basis = (u.full_name or u.first_name or u.username or "").strip()
                    # 最速・禁則回避の名前分解
                    sp = basis.find(" ")
                    if sp == -1:
                        first = basis
                        last = ""
                    else:
                        first = basis[:sp]
                        last = basis[sp+1:]
 
                    emp = frappe.get_doc({
                        "doctype": "Employee",
                        "first_name": first or (u.first_name or u.username),
                        "last_name": last,
                        "status": "Active",
                        "company": "MyHaTch ホールディングス",
                        "date_of_joining": frappe.utils.today(),
                        "user_id": u.name,
                        "personal_email": u.email or None,
                    })
                    emp.insert(ignore_permissions=True)
            finally:
                frappe.flags["sync_user_employee_in_progress"] = False
 

4. Code Explanation

5. Points to note

Server scripts are very useful, but there are a few things to keep in mind.
Here are some common points that people get stuck on.

1. Restrictions imposed by Safe Exec

The server script runs in a safe mode called RestrictedPython. Think of this as a rule that allows you to write code freely, but prohibits dangerous operations.

-import The sentence cannot be used.
(frappe orfrappe.utils (OK) -getattr /setattr / Double Unpack (a, b = ... ) etc. are disabled

• insteadfrappe.flags.get() We use security APIs such as these.

2. Handling doc objects

In event scriptsdoc The variable contains the document to be processed. However, if you confine it to a function, it may become impossible to reference it. Top levelif A simple writing style, listing them side by side, is recommended.

3. Errors and Debugging

• If the input is invalidfrappe.throw() This can warn users.
• Debugging isfrappe.log_error("内容", "タイトル") This can be recorded in the Error Log.
• Since there is no DocType called "Server Script Log" in v15, it will be managed uniformly under Error Log.

5. Impact on Performance

Because the server script is executed "during the save process," heavy processing can slow down the entire screen. For time-consuming processes such as integration with external services, it is appropriate to leave them to background processing.

6. Operational Precautions

Server scripts are stored in a database and are therefore not included in code management tools like Git. Therefore, output to JSON using export-fixtures and include it in the repository, It's important to establish operational rules that allow for tracking.

6. Summary

• Can be used like Salesforce Apex triggers or kintone Webhook functions.
• This system is separate from the ERPNext core and operates based on official Hooks/APIs.
• Therefore, update-resistant and robust expansion is possible.

Furthermore, with the help of AI, anyone can now write these small automation codes in a short amount of time. ERPNext, being open source, is arguably the best "launching pad" for this purpose.

Even workplaces that manage data across multiple systems or using Excel spreadsheets can significantly reduce their workload by centralizing their operations with ERPNext. Moreover, the implementation costs are significantly lower compared to major ERP systems.

We encourage you to utilize ERPNext and server scripts to accelerate the automation of your business processes. Leave the implementation and operation support to us at MyHatch.

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