Conditionals

SevenMark supports conditional rendering using the {{{#if}}} element. Content inside the conditional block is included only when the condition evaluates to true.

Basic Syntax

{{{#if [var(x)] == "value"
This content is shown when the condition is true.
}}}

With Explicit Delimiter

Use :: to explicitly separate the condition from content:

{{{#if [var(count)] > 5 ::
Content with explicit delimiter
}}}

Comparison Operators

Operator	Description
==	Equal
!=	Not equal
>	Greater than
<	Less than
>=	Greater than or equal
<=	Less than or equal

Examples

{{{#if [var(count)] == 10
Count is exactly 10
}}}

{{{#if [var(score)] >= 60
Passed!
}}}

{{{#if [var(level)] < 5
Beginner level
}}}

Logical Operators

Operator	Description
&&	AND
||	OR
!	NOT (prefix)

Examples

{{{#if [var(loggedIn)] == "true" && [var(isAdmin)] == "true"
Admin dashboard
}}}

{{{#if [var(premium)] == "true" || [var(trial)] == "true"
Access granted
}}}

{{{#if ![var(banned)] == "true"
User is not banned
}}}

Grouping with Parentheses

Use parentheses to control operator precedence:

{{{#if ([var(a)] == "1" || [var(b)] == "2") && [var(c)] != null
Complex condition with grouping
}}}

Type Conversion Functions

Function	Description
int(expr)	Convert to integer
len(expr)	Get string length
str(expr)	Convert to string

Examples

{{{#if int([var(age)]) >= 18
Adult content
}}}

{{{#if len([var(name)]) > 0
Name is not empty
}}}

Null Checks

Check if a variable is defined or undefined:

{{{#if [var(optional)] == null
Variable is not defined
}}}

{{{#if [var(required)] != null
Variable is defined
}}}

Null Guard Pattern

Use short-circuit evaluation for safe access:

{{{#if [var(x)] != null && int([var(x)]) > 5
x is defined and greater than 5
}}}

If x is null, the right side of && is not evaluated (short-circuit).

Boolean Literals

Use true and false keywords:

{{{#if [var(enabled)] == true
Feature is enabled
}}}

{{{#if [var(disabled)] == false
Feature is not disabled
}}}

{{{#if (5 > 3) == true
Condition result comparison
}}}

Type Coercion Rules

Equality (==, !=)

• "5" == 5 is true (string parsed as number)
• "abc" == 5 is false (cannot parse)
• null == null is true
• true == true is true

Numeric Comparison (>, <, >=, <=)

Both values must be convertible to numbers:

• 10 > 5 is true
• "10" > 5 is true (string parsed as number)
• "abc" > 5 is false (cannot compare, not converted to 0)
• null > 5 is false (null is not comparable)

Complex Examples

Conditional Navigation

{{{#define #role="admin"}}}

{{{#if [var(role)] == "admin"
**Admin Menu**
- User Management
- System Settings
- Analytics Dashboard
}}}

{{{#if [var(role)] == "user"
**User Menu**
- My Profile
- My Orders
}}}

Conditional Formatting

{{{#define #score="85"}}}

{{{#if int([var(score)]) >= 90
{{{ #style="color:green" **Excellent!** Score: [var(score)] }}}
}}}

{{{#if int([var(score)]) >= 60 && int([var(score)]) < 90
{{{ #style="color:blue" **Good!** Score: [var(score)] }}}
}}}

{{{#if int([var(score)]) < 60
{{{ #style="color:red" **Needs Improvement.** Score: [var(score)] }}}
}}}

With Tables (Block Level)

Conditionals can wrap entire table rows as content blocks:

{{{#define #showDetails="true"}}}

{{{#table
[[[[Product]] [[Price]]]]
[[[[Widget A]] [[$10]]]]
{{{#if [var(showDetails)] == "true"
[[[[Widget A Details]] [[Size: Medium, Color: Blue]]]]
}}}
[[[[Widget B]] [[$20]]]]
}}}

Table Row Conditionals

For more precise control, use conditionals at the row level inside tables:

{{{#table
[[[[Header 1]] [[Header 2]]]]
[[[[Normal Row]] [[Data]]]]
{{{#if [var(condition)] == "true" :: [[[[Conditional Row]] [[More Data]]]] }}}
[[[[Footer]] [[End]]]]
}}}

Key difference: Row-level conditionals use :: delimiter and contain row syntax [[[[cell]] [[cell]]]] directly.

Table Cell Conditionals

Conditionals can also control individual cells within a row:

{{{#table
[[ [[Product]] [[Price]] {{{#if [var(showStock)] == "true" :: [[Stock]] }}} ]]
[[ [[Widget]] [[$10]] {{{#if [var(showStock)] == "true" :: [[5 units]] }}} ]]
}}}

List Item Conditionals

Similar syntax works for list items:

{{{#list #1
[[Always visible item]]
{{{#if [var(showExtra)] == "true" :: [[Conditional item 1]] [[Conditional item 2]] }}}
[[Another visible item]]
}}}

Multiple items can be included in a single conditional block.

Processing Order

1. Variables are substituted first ({{{#define}}} → [var()])
2. Conditions are evaluated
3. Content is expanded (if true) or removed (if false)
4. Nested elements inside conditionals are processed normally

Truthy/Falsy Evaluation

When an expression is used as a boolean (e.g., in logical operators), SevenMark follows JavaScript-style truthy/falsy rules:

Falsy Values

Value	Evaluates To
null	false
"" (empty string)	false
0	false
false	false

Truthy Values

Value	Evaluates To
"0"	true (non-empty string)
"false"	true (non-empty string)
Any non-empty string	true
Non-zero numbers	true
true	true

Important: String "0" and "false" are Truthy

Unlike some languages, the strings "0" and "false" evaluate to true because they are non-empty strings:

{{{#define #value="0"}}}

{{{#if [var(value)]
This WILL be shown because "0" is a non-empty string (truthy)
}}}

Checking String Values Properly

To check if a string represents a falsy concept, use explicit comparison:

{{{#define #enabled="false"}}}

// Wrong: "false" is truthy (non-empty string)
{{{#if [var(enabled)]
This will be shown!
}}}

// Correct: Use explicit comparison
{{{#if [var(enabled)] == "true"
This will NOT be shown
}}}

// Also correct: Convert to int for numeric checks
{{{#define #count="0"}}}
{{{#if int([var(count)]) != 0
This will NOT be shown (int("0") == 0)
}}}

Logical Operator Evaluation

// Truthy evaluation in && and ||
{{{#if [var(name)] && [var(email)]
Both name and email are non-empty
}}}

// NOT operator
{{{#if ![var(disabled)]
Disabled is null or empty
}}}

// Double negation (use !(!x) syntax)
{{{#if !(!([var(value)]))
Value is truthy
}}}

String Literals

String literals are enclosed in double quotes. Since version 2.21.4, escape sequences are supported inside string literals:

Escape Sequence	Result
\"	Literal double quote
\\	Literal backslash

Examples

{{{#if [var(title)] == "He said \"hello\""
Match a string containing double quotes
}}}

{{{#if [var(path)] == "C:\\Users\\docs"
Match a string containing backslashes
}}}

{{{#if [var(msg)] == "line1\\line2 and \"quoted\""
Combined escape sequences
}}}

Without escape sequences, it is impossible to compare against strings that contain double quotes or backslashes.

Important Notes

• Conditions are resolved during preprocessing phase
• Supports nested formatting inside conditional blocks
• Short-circuit evaluation prevents unnecessary computation
• Undefined variables evaluate to null
• Empty strings are falsy, non-empty strings (including "0" and "false") are truthy
• For strict boolean checks, use == "true" or == "false" comparisons
• Only single ! operator is allowed; use !(!x) for double negation
• String literals support \" and \\ escape sequences