Dynamic Data Syntax

Mockzilla uses Handlebars as its primary engine for generating high-fidelity, dynamic responses. This allows you to build complex state machines and business logic directly inside your mocks.

1. The Handlebars-First Philosophy

Handlebars is the "Brain" of your mocks. You should use it whenever your response needs to be more than a static file. Mockzilla uses a Smart Hybrid Engine that preserves JSON types (numbers, booleans) even when using complex Handlebars logic.

2. Advanced Logic Helpers

Control the flow of your data with standard and boolean logic.

Helper	Description	Example
`and`	Returns true if all arguments are truthy.	`{{#if (and $.query.active $.query.admin)}}`
`or`	Returns true if any argument is truthy.	`{{#if (or $.query.id $.query.slug)}}`
`not`	Inverts a boolean value.	`{{#if (not $.query.locked)}}`
`default`	Returns a fallback value if the first is empty.	`{{default $.query.theme "dark"}}`
`eq` / `neq`	Strict equality check.	`{{#if (eq $.query.role "admin")}}`
`gt` / `lt`	Numeric comparisons.	`{{#if (gt state.count 5)}}`

3. Temporal (Time) Helpers

Mocking dates and expirations is easy with built-in time manipulation.

Helper	Description	Example
`now`	Current ISO timestamp.	`{{now}}`
`dateFormat`	Formats a date string.	`{{dateFormat "now" "yyyy-MM-dd"}}`
`dateAdd`	Adds time to a date.	`{{dateAdd "now" 30 "days"}}`
`dateSub`	Subtracts time from a date.	`{{dateSub "now" 1 "hours"}}`

Units supported: years, months, weeks, days, hours, minutes, seconds.

4. Collection Wizards (Array Manipulation)

Sculpt your Mini-DB data or request arrays before returning them.

Helper	Description	Example
`filter`	Filters an array by a key/value pair.	`{{filter db.users "status" "active"}}`
`sort`	Sorts an array by a specific key.	`{{sort db.products "price" "desc"}}`
`slice`	Returns a portion of an array.	`{{slice db.items 0 10}}`
`join`	Joins array elements into a string.	`{{join $.query.tags ", "}}`
`json`	Stringifies an object/array.	`{{{json db.users}}}`

5. String & Number Stylists

Format your data to look production-ready.

Helper	Description	Example
`slugify`	URL-friendly strings.	`{{slugify "Hello World!"}}` → `hello-world`
`truncate`	Limits string length with `...`.	`{{truncate long_text 50}}`
`currency`	Formats numbers as money.	`{{currency 123.4 "USD" "en-US"}}` → `$123.40`
`toFixed`	Controls decimal precision.	`{{toFixed 10.555 2}}` → `10.56`
`math`	Basic arithmetic (`+ - * / %`).	`{{math state.val "+" 1}}`

6. Power Patterns (Masterclass)

The "Search & Paginate" Pattern

Filter a database, sort it, and return a specific page with metadata.

{
  "metadata": {
    "total": {{db.products.length}},
    "returned": {{$.query.limit}},
    "next_page": "{{dateAdd (now) 1 'days'}}"
  },
  "results": [
    {{#each (slice (sort (filter db.products "category" $.query.cat) "price" "asc") 0 5)}}
    {
      "id": "{{this.id}}",
      "slug": "{{slugify this.name}}",
      "price_pretty": "{{currency this.price 'USD'}}",
      "is_cheap": {{#if (lt this.price 20)}}true{{else}}false{{/if}}
    }{{#unless @last}},{{/unless}}
    {{/each}}
  ]
}

The "Dynamic User Role" Pattern

Return different nested structures based on complex permission logic.

{
  "user": "{{faker.person.fullName}}",
  "permissions": {{#if (or (eq $.headers.[x-role] "admin") (eq state.user_id 1))}}
    ["read", "write", "delete", "sudo"]
  {{else}}
    ["read"]
  {{/if}},
  "debug_info": {
    "requested_at": "{{now}}",
    "trace_id": "{{faker.string.uuid}}"
  }
}

7. Smart Context Reference

Goal	Handlebars Syntax
Query Param	`{{$.query.id}}`
JSON Body	`{{$.body.user.email}}`
Path Segment	`{{$.params.[0]}}`
Headers	`{{$.headers.[user-agent]}}`
State	`{{state.variable_name}}`
Mini-DB	`{{db.table_name}}`

8. Type Preservation Mastery

Mockzilla is unique because it preserves JSON types even through Handlebars. If your logic evaluates to a valid JSON primitive (number, boolean, or null) without surrounding quotes, Mockzilla will return that actual type.

{
  "isAdmin": {{#if $.query.admin}}true{{else}}false{{/if}},
  "price": {{math $.query.base "*" 1.1}},
  "raw_data": {{{json db.items}}}
}

(Notice: Use triple braces {{{json ...}}} to prevent Handlebars from HTML-escaping JSON characters!)