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Fix if-tag parsing when 'and/or' appear inside string literals #238

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Fix if-tag parsing when 'and/or' appear inside string literals #238

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146 changes: 107 additions & 39 deletions src/Liquid/Tag/TagIf.php
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Original file line number Diff line number Diff line change
Expand Up @@ -92,64 +92,57 @@ public function render(Context $context)
{
$context->push();

$logicalRegex = new Regexp('/\s+(and|or)\s+/');
$conditionalRegex = new Regexp('/(' . Liquid::get('QUOTED_FRAGMENT') . ')\s*([=!<>a-z_]+)?\s*(' . Liquid::get('QUOTED_FRAGMENT') . ')?/');

$result = '';

foreach ($this->blocks as $block) {
if ($block[0] == 'else') {
$result = $this->renderAll($block[2], $context);

break;
}

if ($block[0] == 'if' || $block[0] == 'elsif') {
// Extract logical operators
$logicalRegex->matchAll($block[1]);

$logicalOperators = $logicalRegex->matches;
$logicalOperators = $logicalOperators[1];
// Extract individual conditions
$temp = $logicalRegex->split($block[1]);

$conditions = [];

foreach ($temp as $condition) {
if ($conditionalRegex->match($condition)) {
$left = (isset($conditionalRegex->matches[1])) ? $conditionalRegex->matches[1] : null;
$operator = (isset($conditionalRegex->matches[2])) ? $conditionalRegex->matches[2] : null;
$right = (isset($conditionalRegex->matches[3])) ? $conditionalRegex->matches[3] : null;

array_push($conditions, [
'left' => $left,
'operator' => $operator,
'right' => $right,
]);
} else {
throw new ParseException("Syntax Error in tag 'if' - Valid syntax: if [condition]");
}
$markup = $block[1];

// quote-aware condition & operator parsing
$parsed = $this->parseConditionsAndOperators($markup, $conditionalRegex);
$conditions = $parsed['conditions'];
$operators = $parsed['operators'];

if (count($conditions) === 0) {
throw new ParseException("Syntax Error in tag 'if' - Valid syntax: if [condition]");
}
if (count($logicalOperators)) {
// If statement contains and/or
$display = $this->interpretCondition($conditions[0]['left'], $conditions[0]['right'], $conditions[0]['operator'], $context);
foreach ($logicalOperators as $k => $logicalOperator) {
if ($logicalOperator == 'and') {
$display = ($display && $this->interpretCondition($conditions[$k + 1]['left'], $conditions[$k + 1]['right'], $conditions[$k + 1]['operator'], $context));
} else {
$display = ($display || $this->interpretCondition($conditions[$k + 1]['left'], $conditions[$k + 1]['right'], $conditions[$k + 1]['operator'], $context));
}

// Evaluate first condition
$display = $this->interpretCondition(
$conditions[0]['left'],
$conditions[0]['right'],
$conditions[0]['operator'],
$context
);

// Apply subsequent conditions with logical operators
foreach ($operators as $index => $logicalOperator) {
$next = $this->interpretCondition(
$conditions[$index + 1]['left'],
$conditions[$index + 1]['right'],
$conditions[$index + 1]['operator'],
$context
);

if ($logicalOperator === 'and') {
$display = $display && $next;
} else {
$display = $display || $next;
}
} else {
// If statement is a single condition
$display = $this->interpretCondition($conditions[0]['left'], $conditions[0]['right'], $conditions[0]['operator'], $context);
}

// hook for unless tag
$display = $this->negateIfUnless($display);

if ($display) {
$result = $this->renderAll($block[2], $context);

break;
}
}
Expand All @@ -165,4 +158,79 @@ protected function negateIfUnless($display)
// no need to negate a condition in a regular `if` tag (will do that in `unless` tag)
return $display;
}

private function parseConditionsAndOperators(string $markup, Regexp $conditionalRegex): array
{
$len = strlen($markup);
$inString = false;
$quote = null;
$buffer = '';
$fragments = [];
$operators = [];

for ($i = 0; $i < $len; $i++) {
$ch = $markup[$i];

// Track entering/leaving string literals
if ($ch === "'" || $ch === '"') {
if (!$inString) {
$inString = true;
$quote = $ch;
} elseif ($quote === $ch) {
$inString = false;
$quote = null;
}

$buffer .= $ch;
continue;
}

if (!$inString) {
// Look for logical " and " outside quotes
if (substr($markup, $i, 5) === ' and ') {
$fragments[] = trim($buffer);
$buffer = '';
$operators[] = 'and';
$i += 4; // skip " and" (loop will add 1 more)
continue;
}

// Look for logical " or " outside quotes
if (substr($markup, $i, 4) === ' or ') {
$fragments[] = trim($buffer);
$buffer = '';
$operators[] = 'or';
$i += 3; // skip " or" (loop will add 1 more)
continue;
}
}

// Default: just accumulate characters
$buffer .= $ch;
}

if (trim($buffer) !== '') {
$fragments[] = trim($buffer);
}

$conditions = [];

foreach ($fragments as $fragment) {
if ($conditionalRegex->match($fragment)) {
$left = isset($conditionalRegex->matches[1]) ? $conditionalRegex->matches[1] : null;
$operator = isset($conditionalRegex->matches[2]) ? $conditionalRegex->matches[2] : null;
$right = isset($conditionalRegex->matches[3]) ? $conditionalRegex->matches[3] : null;

$conditions[] = [
'left' => $left,
'operator' => $operator,
'right' => $right,
];
} else {
throw new ParseException("Syntax Error in tag 'if' - Valid syntax: if [condition]");
}
}

return ['conditions' => $conditions, 'operators' => $operators];
}
}
31 changes: 31 additions & 0 deletions tests/Liquid/Tag/TagIfTest.php
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Original file line number Diff line number Diff line change
Expand Up @@ -286,4 +286,35 @@ public function testSyntaxErrorUnknown()

$this->assertTemplateResult('', '{% unknown-tag %}');
}

public function testStringLiteralWithAndIsComparedLiterally()
{
$text = "{% assign course = 'Art and Design' %}" .
"{% if course == 'Art and Design' %}true{% else %}false{% endif %}";

$this->assertTemplateResult('true', $text);
}

public function testStringLiteralWithOrIsComparedLiterally()
{
$text = "{% assign title = 'History or Politics' %}" .
"{% if title == 'History or Politics' %}true{% else %}false{% endif %}";

$this->assertTemplateResult('true', $text);
}

public function testVarAndStringLiteralWithAndAreEqual()
{
$text = "{% if var == 'Art and Design' %}true{% else %}false{% endif %}";

$this->assertTemplateResult('true', $text, ['var' => 'Art and Design']);
}

public function testLogicalAndStillWorksWithStringLiteralContainingAnd()
{
$text = "{% assign ok = true %}{% assign course = 'Art and Design' %}" .
"{% if ok and course == 'Art and Design' %}true{% else %}false{% endif %}";

$this->assertTemplateResult('true', $text);
}
}
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