Netsuite Suitescript Learning

NetSuite SuiteScript Learning Skill

Created by: Oracle NetSuite

Description

Interactive learning system for NetSuite SuiteScript and SDF projects with SAFE Guide integration. This skill provides:

• Learn Mode: Topic-based learning from SAFE Guide principles (14 topics including governance, performance, security, N/cache, concurrency)
• Review Mode: Analyze code files and identify key learning concepts
• Explain Mode: Deep-dive explanations with automatic SAFE Guide references
• Annotate Mode: Embed educational comments directly into code
• Quiz Mode: Generate quizzes from user code (--source=code), SAFE Guide principles (--source=safe), or both
• Final Mode: Comprehensive learning documentation with SAFE Guide compliance checklist

Covers all 14 script types, deployment configurations, performance patterns, defensive coding practices, and governance limits.

How to Use This Skill

Manual Invocation (Slash Command)

Invoke this skill at any time by typing:

/netsuite-suitescript-learning

Note: /netsuite-suitescript-learning is the full skill command, while /suitescript-learning may be available as a coding assistant alias where supported.

Or use specific mode commands:

/netsuite-suitescript-learning learn [topic] # Learn a SAFE Guide topic
/netsuite-suitescript-learning review [filename] # Review a file and identify learning concepts
/netsuite-suitescript-learning explain [concept] # Deep dive into a specific concept
/netsuite-suitescript-learning annotate [filename] # Add inline learning comments to code
/netsuite-suitescript-learning quiz [section] # Generate quiz questions
/netsuite-suitescript-learning final # Generate a comprehensive learning document

Optional Coding Assistant Activation Example

For Claude Code, add this to your project's .claude/settings.local.json:

{
  "permissions": {
    "allow": [
      "Skill(netsuite-sdf-safe-guide)",
      "Skill(netsuite-suitescript-learning)"
    ]
  }
}

With both skills enabled, an assistant will:

• Follow SDF best practices for all SDF components (scripts, custom records, workflows, etc.)
• Automatically embed educational annotations in code as it's written
• Generate quizzes and learning materials on request
• Provide guidance on Suitelets, RESTlets, User Event Scripts, and all 14 script types

When to Use This Skill

Proactive Invocation (Recommended)

• Invoke this skill during development as code is being written, not just at the end.
• Call after each major component is created (script file, object XML, etc.).
• Use for real-time learning reinforcement.
• IMPORTANT: When creating NetSuite SuiteScript code, automatically embed learning annotations (CONCEPT comments, LEARNING NOTES) directly into the code as it's written.

Automatic Annotation During Code Creation

When this skill is active and code is being created (not just reviewed), the following annotations should be automatically included:

1. JSDoc Headers: Include LEARNING NOTES explaining the script type and purpose.
2. Entry Points: Add LEARNING NOTES blocks explaining when/how the function runs.
3. API Calls: Add CONCEPT comments before each N/* module usage.
4. Complex Logic: Add step-by-step comments for multi-step operations.
5. Return Statements: Explain what's being exposed and why.

This ensures educational content is embedded as code is written, not added as an afterthought.

Manual Invocation

• User explicitly requests educational content: "explain this code", "create a quiz", "review for learning"
• Commands like: "/suitescript-learning", "/quiz", "/explain-suitescript"
• After completing a NetSuite SDF project to generate final learning materials

Invocation Modes

Usage Syntax

/netsuite-suitescript-learning [mode] [target] [options]

Modes:
  learn – Topic-based learning from SAFE Guide principles
  review – Review a specific file and identify learning concepts
  explain – Explain a specific concept or code pattern
  annotate – Add inline learning comments to existing code
  quiz – Generate quiz questions for recent code
  final – Generate final comprehensive learning document

Target:
  - File path for review/annotate mode
  - Concept name for explain mode
  - "all" or section name for quiz mode
  - Topic keyword for learn mode (see SAFE Guide Learning Topics)

Options:
  --source=code Quiz questions from user's code only (quiz mode)
  --source=safe Quiz questions from SAFE Guide principles only (quiz mode)
  --source=owasp Quiz questions from OWASP secure coding practices only (quiz mode)
  --source=both Quiz questions from both sources (default for quiz mode)

Examples:

/suitescript-learning learn ncache
/suitescript-learning learn governance
/suitescript-learning review quick_add_ue.js
/suitescript-learning explain beforeLoad
/suitescript-learning annotate quick_add_cs.js
/suitescript-learning quiz user-event-scripts
/suitescript-learning quiz --source=safe
/suitescript-learning final

Core Functionality

1. Code Review Mode (review)

When reviewing a SuiteScript file, identify and document:

Script Type Analysis

Detect the script type from JSDoc annotations and provide:

• Purpose of this script type
• When it executes (server-side vs client-side)
• Common use cases
• Entry points specific to this type

Key Concepts Extraction

For each code pattern found, document:

• Concept Name: Brief identifier
• What It Does: Plain English explanation
• Why It's Used: Business/technical rationale
• Code Location: Line number reference
• Common Pitfalls: What could go wrong
• Best Practice: Recommended approach

Output Format for Review Mode

## Code Review: [filename]

### Script Overview
- **Type**: [UserEventScript/ClientScript/Suitelet/RESTlet/etc.]
- **Execution Context**: [Server/Client]
- **Entry Points**: [list of entry points used]

### Key Concepts Identified

#### 1. [Concept Name]
**Lines**: [X–Y]
**What**: [explanation]
**Why**: [rationale]
**Pitfall**: [common mistake]
**Best Practice**: [recommendation]

#### 2. [Next Concept]
...

### Quiz Questions for This File
1. [Question about concept 1]
2. [Question about concept 2]
...

2. Explain Mode (explain)

Provide deep-dive explanations for specific concepts:

Supported Concepts (Auto-Detect from User Query)

User Event Script Concepts:

• beforeLoad – Form modification before render
• beforeSubmit – Validation before save
• afterSubmit – Post-save processing
• context.type – Record access modes
• form.addButton() – Custom buttons
• form.clientScriptModulePath – Linking client scripts

Client Script Concepts:

• pageInit – Page load initialization
• saveRecord – Save validation
• validateField – Field-level validation
• fieldChanged – Reactive field handling
• currentRecord.get() – Accessing record data
• selectNewLine/commitLine – Sublist manipulation
• window.opener – Parent window communication

Suitelet Concepts:

• onRequest – HTTP request handling
• GET vs POST – HTTP method routing
• response.write() – Sending responses
• serverWidget.Form – NetSuite forms
• Custom HTML rendering

RESTlet Concepts:

• get/post/put/delete handlers
• JSON responses
• URL parameters vs body
• CORS and authentication

Search & Query Concepts:

• N/search – Saved searches
• N/query – SuiteQL
• Search filters and columns
• search.run().each() – Result iteration
• Performance optimization

Deployment Concepts:

• Script IDs and naming
• Deployment XML structure
• <runasrole> and <allroles> support by type
• <recordtype> requirements
• Status values (RELEASED vs NOTSCHEDULED)
• manifest.xml dependencies

Defensive Coding Concepts:

• runtime.executionContext – Check how script was triggered
• Override vs. Wait patterns – When to defer to other scripts
• Idempotent operations – Safe to re-run without side effects
• Script coordination – Using flag fields for ordering
• Graceful error handling – try/catch in afterSubmit
• Sanity checks – Verify before acting
• search.lookupFields() – Check record exists before loading

Governance Concepts:

• Script.getRemainingUsage() – Monitor remaining usage units
• Usage unit limits by script type – 1,000 for UE/Suitelet, 10,000 for Scheduled
• API governance costs – Different costs for custom vs transaction records
• SSS_USAGE_LIMIT_EXCEEDED – Script exceeded usage units
• SSS_TIME_LIMIT_EXCEEDED – Script exceeded time limit
• Search result limits – 1,000 standard, 4,000 saved search
• Yielding in Scheduled Scripts – Reschedule before hitting limits
• Client Script logging – log.* ignored, use console.log()

Output Format for Explain Mode

## Concept: [Name]

### What It Is
[Clear explanation]

### When to Use It
[Use cases and scenarios]

### How It Works
[Technical details with code examples]

### Example Code
```javascript
[Relevant code snippet]
```

### Common Mistakes
1. [Mistake 1]
2. [Mistake 2]

### Best Practices
1. [Practice 1]
2. [Practice 2]

### Related Concepts
- [Link to related concept 1]
- [Link to related concept 2]

### SAFE Guide Reference
This concept relates to **Principle [X]: [Name]**

Key points from the SAFE Guide:
- [Point 1 from SAFE Guide]
- [Point 2 from SAFE Guide]

See: `../netsuite-sdf-safe-guide/references/[XX-filename.md]`

Concept-to-Principle Mapping

When explaining concepts, automatically reference relevant SAFE Guide principles:

3. Annotate Mode (annotate)

Add inline learning comments directly into code files. This embeds educational content where developers will see it as they work with the code.

Comment Styles

CONCEPT Comments – Brief inline explanations

// CONCEPT: context.type tells us how the record is being accessed
if (context.type !== context.UserEventType.VIEW)

LEARNING NOTES Comments – Block explanations in JSDoc

/**
 * beforeLoad Entry Point
 *
 * LEARNING NOTES:
 * - This function executes BEFORE the form is sent to the browser
 * - Perfect place to modify the form (add fields, buttons, sublists)
 * - context.form gives access to the N/ui/serverWidget.Form object
 *
 * @param {Object} context – Contains form, record, type (view/edit/create)
 */
 const beforeLoad = (context) => {
      const form = context.form;
  };

Parameters Comments – Explain function parameters

// Parameters:
//   id: Unique identifier (prefix with custpage_ for custom buttons)
//   label: What the user sees
//   functionName: Client Script function to call when clicked
form.addButton({
    id: 'custpage_quick_add_items',
    label: 'Quick Add Items',
    functionName: 'openQuickAddDialog'
});

Annotation Rules

1. JSDoc Header Annotations

   • Add LEARNING NOTES block to every entry point function.
   • Include what the function does, when it runs, and key parameters.
   • Reference related concepts and common pitfalls.

2. Inline CONCEPT Comments

   • Add before any non-obvious code pattern.
   • Keep to single line when possible.
   • Focus on the "why" not just the "what".

3. Code Block Explanations

   • Add before complex logic blocks.
   • Use numbered steps for multi-step operations.
   • Include expected outcomes.

4. Return Statement Comments

   • Explain what the return object exposes.
   • Note which functions are entry points vs custom.

Where to Add Annotations

Example: Fully Annotated User Event Script

/**
 * @NApiVersion 2.1
 * @NScriptType UserEventScript
 * @NModuleScope SameAccount
 *
 * @description User Event Script to add "Quick Add Items" button to Sales Orders
 *
 * LEARNING NOTES:
 * - @NApiVersion 2.1 tells NetSuite to use SuiteScript 2.1 (modern JS support)
 * - @NScriptType UserEventScript identifies this as a UE script
 * - @NModuleScope SameAccount restricts execution to same NetSuite account
 * - User Event Scripts run on the SERVER, not in the browser
 */

// CONCEPT: define() is the AMD module pattern; loads dependencies
define(['N/ui/serverWidget', 'N/runtime'], (serverWidget, runtime) => {

    /**
     * beforeLoad Entry Point
     *
     * LEARNING NOTES:
     * - Executes BEFORE the form is sent to the browser
     * - Perfect place to modify the form (add fields, buttons, sublists)
     * - context.form gives access to the N/ui/serverWidget.Form object
     * - Changes made here appear when the page loads
     *
     * @param {Object} context – Contains form, record, type (view/edit/create)
     */
    const beforeLoad = (context) => {
        try {
            // CONCEPT: context.type tells us how the record is being accessed
            // We only want the button in edit or create mode, not view-only
            if (context.type !== context.UserEventType.VIEW) {

                // CONCEPT: context.form is the N/ui/serverWidget.Form object
                // This gives us access to modify the form before rendering
                const form = context.form;

                // CONCEPT: addButton() adds a button to the form's toolbar
                // Parameters:
                //   id: Unique identifier (prefix with custpage_ for custom buttons)
                //   label: What the user sees
                //   functionName: Client Script function to call when clicked
                form.addButton({
                    id: 'custpage_quick_add_items',
                    label: 'Quick Add Items',
                    functionName: 'openQuickAddDialog'
                });

                // CONCEPT: clientScriptModulePath links a Client Script to this form
                // The Client Script will contain our openQuickAddDialog function
                // Path is relative to this script's location in the File Cabinet
                form.clientScriptModulePath = './quick_add_cs.js';
            }
        } catch (error) {
            log.error('beforeLoad Error', error.message);
        }
    };

    // CONCEPT: Return object exposes entry points to NetSuite
    // Only functions returned here are recognized as entry points
    // Custom helper functions inside the module stay private
    return {
        beforeLoad: beforeLoad
    };
});

Annotation Density Guidelines

Too Few: Code is hard to understand for learners. Too Many: Code becomes cluttered and hard to read.

Output Format for Annotate Mode

When annotating a file, provide:

1. Summary of annotations added
2. Count of each annotation type
3. Any areas that couldn't be annotated (and why)

## Annotation Summary: [filename]

### Annotations Added
- LEARNING NOTES blocks: [X]
- CONCEPT comments: [Y]
- Parameters comments: [Z]

### Coverage
- Entry points annotated: [X/Y]
- Complex logic blocks annotated: [X/Y]
- API calls annotated: [X/Y]

### Notes
[Any areas skipped or needing manual review]

4. Learn Mode (learn)

Topic-based learning from SAFE Guide references. This mode generates educational content summarized from the SAFE Guide principles and appendices.

Supported Topics

How Learn Mode Works

1. Read SAFE Guide Reference: Load the netsuite-sdf-safe-guide skill first, then read the relevant reference file from ../netsuite-sdf-safe-guide/references/.
2. Extract Key Concepts: Identify the main principles, patterns, and examples.
3. Generate Summary: Create a structured learning document with examples.
4. Include Quiz Questions: Generate 2–3 quick questions to reinforce learning.

Output Format for Learn Mode

## Learning Topic: [Topic Name]

### Overview
[Brief summary of the topic; 2–3 sentences explaining what this covers and why it matters]

### Key Concepts
1. **[Concept 1]**: [Explanation with code example if applicable]
2. **[Concept 2]**: [Explanation]
3. **[Concept 3]**: [Explanation]

### Best Practices
- [Practice 1]
- [Practice 2]
- [Practice 3]

### Common Pitfalls
| Pitfall | Consequence | Solution |
|---------|-------------|----------|
| [Issue 1] | [What happens] | [How to fix] |
| [Issue 2] | [What happens] | [How to fix] |

### Code Example
```javascript
[Relevant code snippet from SAFE Guide demonstrating the concept]
```

### Quick Quiz
1. [Question about this topic]
2. [Question about this topic]

### Related Topics
- [Link to related SAFE Guide principle or topic]
- [Another related topic]

### Source
Summarized from SAFE Guide Principle [X]: [Name]
Reference file: `../netsuite-sdf-safe-guide/references/[XX-filename.md]`

Example: /suitescript-learning learn ncache

## Learning Topic: N/cache for Concurrent Processing

### Overview
The N/cache module provides server-side caching to reduce redundant API calls and improve
performance in high-concurrency scenarios. Essential for Map/Reduce scripts and any
situation where multiple script executions need to share computed data.

### Key Concepts
1. **Cache Scopes**: PRIVATE (single script), PROTECTED (same bundle), PUBLIC (all scripts)
2. **Cache Loaders**: Functions that compute values on cache miss
3. **TTL (Time-To-Live)**: How long cached data remains valid

### Best Practices
- Use Scope.PROTECTED for SuiteApp-internal caching
- Keep cached data serializable (no functions, circular references)
- Set appropriate TTL based on data volatility

### Common Pitfalls
| Pitfall | Consequence | Solution |
|---------|-------------|----------|
| Using Scope.PUBLIC | Data visible to all scripts in account | Use PROTECTED for SuiteApps |
| Caching non-serializable data | Runtime errors | Only cache JSON-safe objects |
| No TTL consideration | Stale data served | Set TTL based on data freshness needs |

### Code Example
```javascript
define(['N/cache'], (cache) => {
    const configCache = cache.getCache({
        name: 'myAppConfig',
        scope: cache.Scope.PROTECTED
    });

    const getConfig = () => {
        return configCache.get({
            key: 'settings',
            loader: () => {
                // This runs only on cache miss
                return loadConfigFromRecord();
            },
            ttl: 300 // 5 minutes
        });
    };
});
```

### Quick Quiz
1. When should you use Scope.PROTECTED vs Scope.PUBLIC?
2. What happens when the cache loader function is called?

### Related Topics
- Performance optimization (Principle 3)
- Map/Reduce scripts
- Governance limits

### Source
Summarized from SAFE Guide Appendix: N/cache Sample Implementation
Reference file: `../netsuite-sdf-safe-guide/references/appendices/appendix-ncache-sample.md`

5. Quiz Mode (quiz)

Generate quiz questions with answers based on written code.

Question Types

Type 1: Conceptual Understanding

Q: What is the difference between beforeLoad and beforeSubmit entry points?
A: beforeLoad runs when the form is being built (before render), while beforeSubmit
   runs when the user clicks Save (before the record is written to the database).

Type 2: Code Prediction

Q: What will happen if you call form.addButton() in afterSubmit instead of beforeLoad?
A: Nothing visible; the form has already been rendered and submitted. The button
   would never appear because afterSubmit runs after the save operation completes.

Type 3: Error Identification

Q: This RESTlet deployment XML will fail. Why?
   <scriptdeployment>
     <runasrole>ADMINISTRATOR</runasrole>
     <allroles>T</allroles>
   </scriptdeployment>
A: RESTlets do not support <runasrole> or <allroles> elements. These must be removed.

Type 4: Best Practice

Q: Why do we use url.resolveScript() instead of hardcoding a Suitelet URL?
A: resolveScript() dynamically generates the correct URL for the current environment
   (sandbox vs production), handles URL encoding, and includes necessary parameters
   like company ID and deployment ID.

Type 5: Fill in the Blank

Q: To add a line to a sublist, you must call three methods in order:
   _______, setCurrentSublistValue(), and _______.
A: selectNewLine(), commitLine()

SAFE Guide Question Types (--source=safe or --source=both)

Type 6: SAFE Guide Principle Application

Q: According to the SAFE Guide, why should you use N/cache with Scope.PROTECTED
   when multiple scripts need to share cached data?
A: Scope.PROTECTED allows cache sharing across all scripts in the same SuiteApp
   bundle while isolating data from other SuiteApps. This provides data privacy
   between different publishers' SuiteApps.

Type 7: Governance Scenario

Q: A User Event Script is taking too long. According to SAFE Guide Principle 2,
   what's the recommended approach when you need to process 500+ records?
A: Offload heavy processing to a Map/Reduce script using N/task. User Event
   Scripts have a 1,000 unit limit; Map/Reduce has 10,000 units per stage.
   This pattern is called "async offloading."

Type 8: Architecture Decision

Q: You need to make AJAX calls from a popup Suitelet. According to Principle 3,
   why should you not use a RESTlet for this?
A: RESTlets count against the Web Services concurrent user limit (typically 5).
   Use the Suitelet-as-API pattern instead, which uses the user's existing session
   and doesn't consume web services slots.

Type 9: OWASP Security Application (--source=owasp or --source=both)

Q: This RESTlet accepts a customer ID from the URL and uses it in a SuiteQL query.
   What OWASP vulnerability is present in this code?
   const id = context.request.parameters.custId;
   const sql = "SELECT * FROM Customer WHERE id = " + id;
A: SQL Injection (OWASP A03:2021). The customer ID is concatenated directly into
   the query string without validation or parameterization. Fix: use parameterized
   query with ? placeholder: query.runSuiteQL({ query: 'SELECT * FROM Customer WHERE id = ?', params: [parseInt(id, 10)] })

Quiz Sources

Question Distribution by Source:

Output Format for Quiz Mode

## Quiz: [Section/Topic Name]

### Questions

**1. [Question text]**

**2. [Question text]**

**3. [Question text]**

**4. [Question text]**

**5. [Question text]**

---

### Answer Key

**1.** [Full answer with explanation]

**2.** [Full answer with explanation]

**3.** [Full answer with explanation]

**4.** [Full answer with explanation]

**5.** [Full answer with explanation]

6. Final Mode (final)

Generate comprehensive learning documentation for the entire project, including a SAFE Guide compliance review.

Final Document Structure

# [Project Name] – Learning Guide

## Project Overview
[Description of what was built and why]

## Architecture Diagram
[ASCII or text-based architecture visualization]

## Learning Objectives
By completing this project, you should understand:
- [ ] Objective 1
- [ ] Objective 2
- [ ] Objective 3

---

## Section 1: [Component Name]

### What This Section Accomplishes
[Plain English description]

### Key Concepts
[List of concepts with brief explanations]

### Code Walkthrough
[Annotated code with LEARNING NOTES comments]

### Section Quiz
[5 questions specific to this section]

---

## Section 2: [Next Component]
...

---

## Comprehensive Quiz

### All Questions (Combined)
[All questions from all sections]

### Answer Key
[All answers with detailed explanations]

---

## SAFE Guide Compliance Review

### Principles Applied
| Principle | Status | Notes |
|-----------|--------|-------|
| 1. Use NetSuite Features | ✅ Applied | Using native SuiteScript modules |
| 2. Governance | ✅ Applied | Script uses getRemainingUsage() checks |
| 3. Performance | ⚠️ Review | Consider N/cache for repeated lookups |
| 4. Multi-SuiteApp | ✅ Applied | Defensive coding patterns used |
| 5. Security | ✅ Applied | Input validation implemented |
| 6. Testing | ⏳ Pending | Add Jest unit tests |
| 11. Secure Coding | ✅ Applied | No eval(), proper escaping |

### Recommendations
Based on SAFE Guide principles, consider:
1. [Specific recommendation based on code analysis]
2. [Another recommendation referencing SAFE Guide principle]
3. [Performance optimization suggestion from Principle 3]

### Reference Files Consulted
- `../netsuite-sdf-safe-guide/references/[relevant-files.md]`

---

## Common Pitfalls Reference

| Pitfall | Symptom | Solution |
|---------|---------|----------|
| **Missing N/log import** | Script fails silently, no errors logged | Add `'N/log'` to define() and `log` to callback parameters. |
| **Relative clientScriptModulePath in SuiteApp** | Button appears but click does nothing | Use full path: `/SuiteApps/com.publisher.appid/scripts/my_cs.js`. |
| **Using log.debug() without N/log** | Script throws error or fails silently | Import N/log module - it's not globally available in SS 2.x. |
| **RESTlet with runasrole/allroles** | Deployment fails with validation error | Remove `<runasrole>` and `<allroles>` from RESTlet XML. |
| **Missing SERVERSIDESCRIPTING feature** | Deployment fails | Add feature to manifest.xml dependencies. |
| **Wrong status value** | Script doesn't execute | Use RELEASED for most scripts, NOTSCHEDULED for MapReduce/Scheduled. |
| **Bracket notation missing in scriptfile** | Deployment fails, file not found | Wrap paths: `[/SuiteApps/path/file.js]`. |
| **Custom button without custpage_ prefix** | May conflict with native buttons | Always prefix custom element IDs with `custpage_`. |
| **RESTlet for user-facing AJAX** | Fails when 6+ users concurrent | Use Suitelet-as-API pattern instead (see below). |
| **window.opener not finding function** | "Could not communicate with parent window" | Use postMessage API + module-level listener (see below). |
| **pageInit not firing with clientScriptModulePath** | Event listeners never set up, code never runs | Put critical setup code at MODULE LEVEL, outside any function. |
| **Search includes salesdescription** | Returns unrelated items (false positives) | Search only `itemid` and `displayname` - descriptions often contain unexpected terms. |
| **Per-item pricing lookups (N+1)** | Search is very slow (~5 seconds) | Use batch lookup with `anyof` filter: `['item', 'anyof', itemIds]`. |
| **DEBUG logging in production** | Excessive log volume, performance impact | Change `<loglevel>` to `AUDIT` or `ERROR` in deployment XML. |

## Performance Optimization

### N+1 Query Problem

**CRITICAL:** Avoid running queries inside loops. This is the most common performance killer in SuiteScript.

**Bad Pattern (N+1):**
```javascript
// 1 search + 50 pricing lookups = 51 queries!
itemSearch.run().each((result) => {
    const price = getItemPrice(result.id); // ← Separate query per item!
});
```

**Good Pattern (Batch):**
```javascript
// Collect IDs first, then ONE batch query
const itemIds = [];
itemSearch.run().each((result) => {
    itemIds.push(result.id);
});

// Single batch lookup for ALL items
const prices = getBatchPricing(itemIds); // Uses ['item', 'anyof', itemIds]
```

**Performance Comparison:**
| Approach | Queries | Time (50 items) |
|----------|---------|-----------------|
| N+1 | 51 | ~5 seconds |
| Batch | 2 | ~200ms |

## Popup Communication in NetSuite

### The Problem with window.opener

NetSuite uses **frames/iframes** for its UI. When you open a popup (Suitelet), `window.opener` points to the **top-level window**, not the frame where your Client Script runs.

```javascript
// This FAILS in NetSuite:
window.opener.myFunction(data); // window.opener exists but myFunction is undefined
```

### The Solution: postMessage API

Use `postMessage` to broadcast messages to all frames:

**Client Script (module-level, NOT in pageInit):**
```javascript
define(['N/currentRecord'], (currentRecord) => {
    // CRITICAL: Module-level code, not in pageInit
    // pageInit may not fire with clientScriptModulePath
    window.addEventListener('message', (event) => {
        // SECURITY: Use anchored regex to prevent origin spoofing
        // For example, "evil-netsuite.com" would pass .includes() but fails this check
        if (!/^https:\/\/([a-z0-9-]+\.)*netsuite\.com$/.test(event.origin)) return;
        if (event.data?.action === 'addItems') {
            handleAddItems(event.data.items);
        }
    });
});
```

**Popup (Suitelet HTML):**
```javascript
function sendToParent(items) {
    const message = { action: 'addItems', items };
    // SECURITY: Use specific origin, never wildcard '*'
    const targetOrigin = window.location.origin;
    window.opener.postMessage(message, targetOrigin);
    // Also post to all frames
    for (let i = 0; i < window.opener.frames.length; i++) {
        window.opener.frames[i].postMessage(message, targetOrigin);
    }
    window.close();
}
```

### Why Module-Level, Not pageInit?

When using `clientScriptModulePath` (set in User Event Script), `pageInit` **may not fire reliably**. Always put critical initialization at the module level:

```javascript
define(['N/currentRecord'], (currentRecord) => {
    // ✅ GOOD: Module-level; always runs when script loads
    console.log('Script loaded');
    window.addEventListener('message', handler);

    // ❌ BAD: pageInit; may not fire with clientScriptModulePath
    const pageInit = (context) => {
        window.addEventListener('message', handler); // May never execute!
    };
});
```

## Concurrency Considerations

### RESTlet vs Suitelet for AJAX Calls

**CRITICAL:** RESTlets count against the Web Services Concurrent User Limit (typically 5). This is a major scalability concern.

| Script Type | Concurrency Model | Best For |
|-------------|-------------------|----------|
| **RESTlet** | Web Services slots (limited to 5) | External integrations, APIs |
| **Suitelet** | User sessions (unlimited) | User-facing features, AJAX |

### Suitelet-as-API Pattern

For popups, modals, and interactive features that need AJAX calls:

```javascript
// Single Suitelet handles both UI and API
const => {
    const action = context.request.parameters.action;

    if (action === 'search') {
        // Return JSON for AJAX calls
        context.response.setHeader({ name: 'Content-Type', value: 'application/json' });
        context.response.write(JSON.stringify({ items: searchResults }));
    } else {
        // Return HTML for page load
        context.response.write(generateHtmlPage());
    }
};
```

**Benefits:**
- No Web Services concurrency limits
- Single script to maintain
- Uses existing user session (no extra auth)
- Scales with user base

## Quick Reference Card

### Module Import Pattern
```javascript
define(['N/search', 'N/record', 'N/log'], (search, record, log) => {
    // Module names in array must match parameter order
});
```

### Client Script Path (SuiteApp)
```javascript
// CORRECT for SuiteApps:
form.clientScriptModulePath = '/SuiteApps/com.publisher.appid/scripts/my_cs.js';

// WRONG for SuiteApps (works in Account Customization only):
form.clientScriptModulePath = './my_cs.js';
```

### Sublist Line Addition Pattern
```javascript
record.selectNewLine({ sublistId: 'item' });
record.setCurrentSublistValue({ sublistId: 'item', fieldId: 'item', value: itemId });
record.setCurrentSublistValue({ sublistId: 'item', fieldId: 'quantity', value: qty });
record.commitLine({ sublistId: 'item' });
```

## Next Steps
[Suggestions for extending the project or learning more]

Script Type Reference

Concepts by Script Type

UserEventScript

ClientScript

Suitelet

RESTlet

Deployment XML Reference

Element Support by Script Type

Quiz Generation Rules

Per-File Minimums

• UserEventScript: 5 questions
• ClientScript: 5 questions
• Suitelet: 5 questions
• RESTlet: 5 questions
• Object XML: 3 questions per file
• manifest.xml: 2 questions

Question Distribution

• 40% Conceptual Understanding
• 25% Code Prediction
• 15% Error Identification
• 15% Best Practice
• 5% Fill in the Blank

Difficulty Levels

• Basic: What does X do?
• Intermediate: When would you use X vs Y?
• Advanced: What happens if X fails? How would you optimize?

Integration with Development Workflow

Recommended Invocation Points

1. After creating a new script file:

   /suitescript-learning review [filename]
   

2. After completing a logical section:

   /suitescript-learning quiz [section-name]
   

3. When encountering a new concept:

   /suitescript-learning explain [concept]
   

4. At project completion:

   /suitescript-learning final
   

Automated Triggers (Proactive Mode)

When this skill is active, automatically:

1. Detect when a new .js file is created in a SuiteScript directory.
2. Identify the script type from JSDoc annotations.
3. Flag key concepts as code is written.
4. Suggest quiz questions based on patterns used.
5. Maintain a running list of concepts for final review.

Example Output

Example: Review of a User Event Script

## Code Review: quick_add_ue.js

### Script Overview
- **Type**: UserEventScript
- **Execution Context**: Server-side
- **Entry Points Used**: beforeLoad

### Key Concepts Identified

#### 1. JSDoc Annotations (@NApiVersion, @NScriptType)
**Lines**: 1–8
**What**: Metadata comments that tell NetSuite how to interpret the script
**Why**: NetSuite requires these to properly deploy and execute the script
**Pitfall**: Forgetting @NScript

…(truncated)