# Template Link Enhancement Implementation

This document summarizes the enhancements made to the iOS app's template link functionality.

## Features Implemented

### 1. Enhanced Template Help Text
- **Location**: LinkFormView.swift (when template type is selected)
- **Content**: Added detailed explanation with example
  ```
  Template type allows you to create dynamic URLs with parameters. Use {query, default=value} syntax in the URL.

  Example: https://google.com/search?q={query, default=hello}
  ```

### 2. Real-time Template Validation
- **Visual feedback with iOS blue highlighting** when template is valid
- **Warning messages** when template has no parameters
- **Error messages** when template syntax is invalid

### 3. Border Color Indicators
- **Blue border**: Valid template with parameters
- **Orange border**: Invalid URL or template syntax error
- **Clear border**: Normal state

### 4. Template Validation States
- ✅ **Valid with parameters**: Shows blue checkmark with "Valid template with parameters"
- ⚠️ **No parameters**: Shows orange warning "Template should contain parameters like {query} or {query,default=value}"
- ❌ **Invalid syntax**: Shows red error "Invalid template syntax. Use {parameter} or {parameter,default=value}"

## Technical Implementation

### URLTemplateProcessor Enhancements
- **Updated regex pattern** to handle flexible spacing: `{query, default=value}` vs `{query,default=value}`
- **Improved parameter extraction** with whitespace trimming
- **Enhanced validation** using existing processor methods

### LinkFormView Changes
- **New computed property**: `templateValidationView` for real-time feedback
- **Enhanced border styling**: `getBorderColor()` method for dynamic colors
- **Improved URL validation**: Better template-specific validation logic

### Localization Updates
- **English**: Added `invalid_template_format` and `invalid_base_url_format`
- **Chinese**: Added corresponding translations

## Supported Template Formats

The implementation supports both syntax formats:
- `{parameter}` - Required parameter
- `{parameter, default=value}` - Parameter with default value (flexible spacing)
- `{parameter,default=value}` - Parameter with default value (no spacing)

## Example Templates

✅ **Valid Templates:**
- `https://google.com/search?q={query}`
- `https://google.com/search?q={query, default=hello}`
- `https://github.com/{user}/{repo}`
- `https://maps.apple.com/?q={location,default=New York}`

⚠️ **Templates needing parameters:**
- `https://example.com/no-parameters`

❌ **Invalid syntax examples:**
- URLs with malformed parameter syntax
- Non-URL strings when template type is selected

## User Experience

1. **Select Template type** in link form
2. **See helpful tips** with syntax explanation and example
3. **Enter URL with parameters** - real-time validation appears
4. **Visual feedback**:
   - Blue border and checkmark for valid templates
   - Orange warning for templates without parameters
   - Red error for invalid syntax
5. **Clear error messages** to guide correction

The implementation provides a smooth, intuitive experience for creating dynamic URL templates with immediate feedback.
