Template Variables

Complete reference guide for all template variables available in moclojer. Learn how to access request data and use built-in functions in your responses.

This reference guide provides a complete list of all template variables available in moclojer. Template variables use the {{variable}} syntax and are replaced with actual values when processing requests.

Path Parameters

Extract values from URL path segments defined with :parameter syntax.

Syntax

path: /users/:id/posts/:postId
body: >
  {
    "user_id": "{{path-params.id}}",
    "post_id": "{{path-params.postId}}"
  }

Examples

Single parameter:

path: /users/:id
# Request: GET /users/123
# Result: {{path-params.id}} = "123"

Multiple parameters:

path: /api/:version/users/:userId/posts/:postId
# Request: GET /api/v1/users/456/posts/789
# Results:
# {{path-params.version}} = "v1"
# {{path-params.userId}} = "456"
# {{path-params.postId}} = "789"

Typed parameters:

path: /users/:id|int/profile/:section|string
# Request: GET /users/123/profile/settings
# Results:
# {{path-params.id}} = "123" (validated as integer)
# {{path-params.section}} = "settings" (validated as string)

Available Types

string (default) - Any string value
int - Integer numbers only
uuid - UUID format validation
date - Date format validation
boolean - Boolean values (true/false)

Query Parameters

Access URL query string parameters that come after the ? in URLs.

Syntax

# Request: GET /search?q=javascript&category=tutorials&page=2
body: >
  {
    "query": "{{query-params.q}}",
    "category": "{{query-params.category}}",
    "page": "{{query-params.page}}"
  }

Examples

Simple query parameters:

# Request: GET /products?sort=price&order=asc
# Results:
# {{query-params.sort}} = "price"
# {{query-params.order}} = "asc"

Array parameters:

# Request: GET /products?tags=electronics&tags=wireless&tags=audio
# Results:
# {{query-params.tags}} = "electronics" (first value)
# Note: moclojer returns the first value for duplicate parameters

URL encoded parameters:

# Request: GET /search?q=hello%20world&filter=name%3Ajohn
# Results:
# {{query-params.q}} = "hello world" (automatically decoded)
# {{query-params.filter}} = "name:john" (automatically decoded)

JSON Body Parameters

Access data from JSON request bodies in POST, PUT, PATCH requests.

Syntax

# Request body: {"name": "John", "email": "[email protected]", "age": 30}
body: >
  {
    "id": 12345,
    "name": "{{json-params.name}}",
    "email": "{{json-params.email}}",
    "age": {{json-params.age}}
  }

Examples

Simple properties:

# Request body: {"username": "john_doe", "password": "secret123"}
# Results:
# {{json-params.username}} = "john_doe"
# {{json-params.password}} = "secret123"

Nested objects:

# Request body: {"user": {"profile": {"name": "John", "age": 30}}}
# Results:
# {{json-params.user.profile.name}} = "John"
# {{json-params.user.profile.age}} = "30"

Array elements:

# Request body: {"tags": ["javascript", "tutorial", "beginner"]}
# Results:
# {{json-params.tags.0}} = "javascript"
# {{json-params.tags.1}} = "tutorial"
# {{json-params.tags.2}} = "beginner"

Complex nested structures:

# Request body:
# {
#   "order": {
#     "items": [
#       {"product": "laptop", "price": 999.99},
#       {"product": "mouse", "price": 29.99}
#     ],
#     "shipping": {"address": "123 Main St", "city": "Boston"}
#   }
# }
# Results:
# {{json-params.order.items.0.product}} = "laptop"
# {{json-params.order.items.0.price}} = "999.99"
# {{json-params.order.shipping.address}} = "123 Main St"

Data Type Handling

Strings (require quotes):

"name": "{{json-params.name}}"

Numbers (no quotes needed):

"age": {{json-params.age}},
"price": {{json-params.price}}

Booleans (no quotes needed):

"active": {{json-params.active}},
"verified": {{json-params.verified}}

Header Parameters

Access HTTP request headers using the header name.

Syntax

body: >
  {
    "user_agent": "{{header-params.User-Agent}}",
    "content_type": "{{header-params.Content-Type}}",
    "authorization": "{{header-params.Authorization}}"
  }

Examples

Standard headers:

# Request headers:
# User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64)
# Content-Type: application/json
# Authorization: Bearer token123
# Results:
# {{header-params.User-Agent}} = "Mozilla/5.0 (Windows NT 10.0; Win64; x64)"
# {{header-params.Content-Type}} = "application/json"
# {{header-params.Authorization}} = "Bearer token123"

Custom headers:

# Request headers:
# X-API-Key: abc123def456
# X-Request-ID: req-789
# X-User-Role: admin
# Results:
# {{header-params.X-API-Key}} = "abc123def456"
# {{header-params.X-Request-ID}} = "req-789"
# {{header-params.X-User-Role}} = "admin"

Case sensitivity:

# Headers are case-insensitive in HTTP, but use exact case in templates:
# {{header-params.content-type}} = same as Content-Type
# {{header-params.CONTENT-TYPE}} = same as Content-Type
# {{header-params.Content-Type}} = recommended format

Built-in Functions

Special template functions that provide dynamic values.

`{{now}}`

Returns the current timestamp in ISO 8601 format.

body: >
  {
    "created_at": "{{now}}",
    "timestamp": "{{now}}"
  }
# Result: "2024-01-15T10:30:00.000Z"

`{{uuid}}`

Generates a random UUID v4.

body: >
  {
    "id": "{{uuid}}",
    "transaction_id": "{{uuid}}"
  }
# Result: "123e4567-e89b-12d3-a456-426614174000"

`{{random}}`

Generates random numbers (if supported).

body: >
  {
    "random_id": "{{random}}",
    "session_id": "sess_{{random}}"
  }

WebSocket Template Variables

Special variables available in WebSocket responses.

`{{message}}`

The complete received message content.

websocket:
  path: /ws/echo
  on-message:
    - pattern: ".*"
      response: >
        {
          "echo": {{message}},
          "timestamp": "{{now}}"
        }

WebSocket Path Parameters

Same as HTTP path parameters.

websocket:
  path: /ws/chat/:room_id
  on-connect:
    response: >
      {
        "room": "{{path-params.room_id}}",
        "status": "connected"
      }

Advanced Usage

Combining Multiple Parameters

# Combine different parameter types
path: /api/:version/users/:id
body: >
  {
    "api_version": "{{path-params.version}}",
    "user_id": "{{path-params.id}}",
    "updated_name": "{{json-params.name}}",
    "client_ip": "{{header-params.X-Forwarded-For}}",
    "search_query": "{{query-params.q}}",
    "timestamp": "{{now}}"
  }

Conditional Content

# Basic conditional logic (if supported)
body: >
  {
    "message": "{{#if query-params.admin}}Admin access{{else}}Regular user{{/if}}",
    "role": "{{query-params.role}}"
  }

String Interpolation

# Embed variables within strings
body: >
  {
    "welcome_message": "Hello, {{json-params.name}}! Welcome to {{path-params.service}}",
    "full_url": "https://api.example.com{{path-params.endpoint}}?key={{query-params.api_key}}"
  }

Error Handling

Missing Parameters

When a parameter is not present in the request, it appears as an empty string:

# If request doesn't include 'optional_param'
"value": "{{query-params.optional_param}}"
# Result: "value": ""

Invalid JSON

If JSON body is malformed, json-params will be empty:

# Invalid JSON request body
"name": "{{json-params.name}}"
# Result: "name": ""

Special Characters

Template variables handle URL encoding and JSON escaping automatically:

# Query: ?message=hello%20world%26more
"decoded": "{{query-params.message}}"
# Result: "decoded": "hello world&more"

Best Practices

1. Use Appropriate Data Types

# Good - numbers without quotes
"age": {{json-params.age}},
"price": {{json-params.price}}

# Bad - numbers with quotes become strings
"age": "{{json-params.age}}"

2. Provide Default Values

# Use fallback values for optional parameters
"page": {{query-params.page}},
"default_message": "Page {{query-params.page}} or 1 if not specified"

3. Validate Parameter Types

# Use typed path parameters for validation
path: /users/:id|int/orders/:orderId|uuid

4. Handle Missing Parameters Gracefully

# Design responses to work with missing optional parameters
"filters": {
  "category": "{{query-params.category}}",
  "sort": "{{query-params.sort}}",
  "note": "Empty values indicate parameter not provided"
}

5. Use Meaningful Parameter Names

# Good - clear parameter names
path: /users/:userId/posts/:postId

# Less clear
path: /users/:id1/posts/:id2

Examples by Use Case

User Profile API

- endpoint:
    method: GET
    path: /users/:id/profile
    response:
      body: >
        {
          "user_id": "{{path-params.id}}",
          "include_private": {{query-params.private}},
          "requested_by": "{{header-params.X-User-ID}}",
          "timestamp": "{{now}}"
        }

Product Search

- endpoint:
    method: GET
    path: /products/search
    response:
      body: >
        {
          "query": "{{query-params.q}}",
          "category": "{{query-params.category}}",
          "min_price": {{query-params.min_price}},
          "max_price": {{query-params.max_price}},
          "results": []
        }

Order Creation

- endpoint:
    method: POST
    path: /orders
    response:
      body: >
        {
          "order_id": "ORD-{{uuid}}",
          "customer_id": "{{json-params.customer_id}}",
          "items": {{json-params.items}},
          "total": {{json-params.total}},
          "created_at": "{{now}}",
          "user_agent": "{{header-params.User-Agent}}"
        }

This reference covers all available template variables in moclojer. For more advanced templating techniques, see Advanced Templating.

PreviousTemplate System Overview NextPath Parameters

Last updated 1 month ago

Was this helpful?

hashtagPath Parameters

hashtagSyntax

hashtagExamples

hashtagAvailable Types

hashtagQuery Parameters

hashtagSyntax

hashtagExamples

hashtagJSON Body Parameters

hashtagSyntax

hashtagExamples

hashtagData Type Handling

hashtagHeader Parameters

hashtagSyntax

hashtagExamples

hashtagBuilt-in Functions

hashtag{{now}}

hashtag{{uuid}}

hashtag{{random}}

hashtagWebSocket Template Variables

hashtag{{message}}

hashtagWebSocket Path Parameters

hashtagAdvanced Usage

hashtagCombining Multiple Parameters

hashtagConditional Content

hashtagString Interpolation

hashtagError Handling

hashtagMissing Parameters

hashtagInvalid JSON

hashtagSpecial Characters

hashtagBest Practices

hashtag1. Use Appropriate Data Types

hashtag2. Provide Default Values

hashtag3. Validate Parameter Types

hashtag4. Handle Missing Parameters Gracefully

hashtag5. Use Meaningful Parameter Names

hashtagExamples by Use Case

hashtagUser Profile API

hashtagProduct Search

hashtagOrder Creation

Path Parameters

Syntax

Examples

Available Types

Query Parameters

Syntax

Examples

JSON Body Parameters

Syntax

Examples

Data Type Handling

Header Parameters

Syntax

Examples

Built-in Functions

`{{now}}`

`{{uuid}}`

`{{random}}`

WebSocket Template Variables

`{{message}}`

WebSocket Path Parameters

Advanced Usage

Combining Multiple Parameters

Conditional Content

String Interpolation

Error Handling

Missing Parameters

Invalid JSON

Special Characters

Best Practices

1. Use Appropriate Data Types

2. Provide Default Values

3. Validate Parameter Types

4. Handle Missing Parameters Gracefully

5. Use Meaningful Parameter Names

Examples by Use Case

User Profile API

Product Search

Order Creation