Template Errors

Template Errors (Smarty Debugging)

Common Smarty template issues and debugging techniques for XOOPS themes and modules.

Diagnostic Flowchart

flowchart TD
    A[Template Error] --> B{Error Visible?}
    B -->|No| C[Enable Template Debug]
    B -->|Yes| D[Read Error Message]

    C --> E{Type of Error?}
    E -->|Syntax| F[Check Template Syntax]
    E -->|Variable| G[Check Variable Assignment]
    E -->|Plugin| H[Check Smarty Plugin]

    D --> I{Parse Error?}
    I -->|Yes| J[Check Braces Matching]
    I -->|No| K{Undefined Variable?}

    K -->|Yes| L[Check Variable in PHP]
    K -->|No| M{File Not Found?}

    M -->|Yes| N[Check Template Path]
    M -->|No| O[Clear Cache]

    F --> P[Fix Syntax]
    G --> Q[Verify PHP Code]
    H --> R[Install Plugin]
    J --> P
    L --> Q
    N --> S[Verify paths]
    O --> T{Error Resolved?}
    P --> T
    Q --> T
    R --> T
    S --> T

    T -->|No| U[Enable Debug Mode]
    T -->|Yes| V[Problem Solved]
    U --> D

Common Smarty Template Errors

pie title Template Error Types
    "Syntax Errors" : 25
    "Undefined Variables" : 25
    "Missing Plugins" : 15
    "Cache Issues" : 20
    "Encoding Problems" : 10
    "Path Issues" : 5

1. Syntax Errors

Symptoms:

“Smarty syntax error” messages
Templates won’t compile
Blank page with no output

Error Messages:

Syntax error: unrecognized tag 'myfunction'
Unexpected "}" near end of template

Common Syntax Issues

Missing closing tag:

{* WRONG *}
{if $user}
User: {$user.name}
{* Missing {/if} *}

{* CORRECT *}
{if $user}
User: {$user.name}
{/if}

Incorrect variable syntax:

{* WRONG *}
{$user->name}          {* Use . not -> *}
{$array[key]}          {* Use quoted keys *}
{$func()}              {* Can't call functions directly *}

{* CORRECT *}
{$user.name}
{$array.key}
{$array['key']}
{$user|@function}      {* Use modifiers instead *}

Mismatched quotes:

{* WRONG *}
{if $name == 'John}     {* Mismatched quotes *}
{assign var="user' value="John"}

{* CORRECT *}
{if $name == 'John'}
{assign var="user" value="John"}

Solutions:

{* Always balance braces *}
{if condition}
  ...
{elseif condition}
  ...
{else}
  ...
{/if}

{* Verify tag format *}
{foreach $items as $item}
  ...
{/foreach}

{* Check all variables are defined *}
{if isset($variable)}
  {$variable}
{/if}

2. Undefined Variable Errors

Symptoms:

“Undefined variable” warnings
Variable displays as empty
PHP notice in error log

Error Messages:

Notice: Undefined variable: myvar
Smarty notice: variable "$user" not available

Debug Script:

<?php
// In your template file or PHP code
// Create modules/yourmodule/debug_template.php

require_once '../../mainfile.php';

// Get template engine
$tpl = new XoopsTpl();

// Check what variables are assigned
echo "<h1>Template Variables</h1>";
echo "<pre>";
print_r($tpl->get_template_vars());
echo "</pre>";

// Or dump Smarty object
echo "<h1>Smarty Debug</h1>";
echo "<pre>";
$tpl->debug_vars();
echo "</pre>";
?>

Fix in PHP:

<?php
// Ensure variables are assigned before rendering
$xoopsTpl = new XoopsTpl();

// WRONG - variable not assigned
$xoopsTpl->display('file:templates/page.html');

// CORRECT - assign variables first
$user = [
    'name' => 'John',
    'email' => 'john@example.com'
];
$xoopsTpl->assign('user', $user);
$xoopsTpl->display('file:templates/page.html');
?>

Fix in Template:

{* Check if variable exists before using *}
{if isset($user)}
    <p>User: {$user.name}</p>
{else}
    <p>No user data</p>
{/if}

{* Use default values *}
<p>Name: {$user.name|default:"No name"}</p>

{* Check array key exists *}
{if isset($array.key)}
    {$array.key}
{/if}

3. Missing or Incorrect Modifiers

Symptoms:

Data doesn’t format correctly
Text displays as HTML
Incorrect case/encoding

Error Messages:

Warning: undefined modifier 'stripslashes'

Common Modifiers:

{* String operations *}
{$text|upper}                    {* Uppercase *}
{$text|lower}                    {* Lowercase *}
{$text|capitalize}               {* First letter capital *}
{$text|truncate:20:"..."}        {* Truncate to 20 chars *}
{$text|strip_tags}               {* Remove HTML tags *}

{* HTML/Formatting *}
{$html|escape}                   {* HTML escape *}
{$html|escape:'html'}
{$url|escape:'url'}              {* URL escape *}
{$text|nl2br}                    {* Newlines to <br> *}

{* Arrays *}
{$array|@count}                  {* Array count *}
{$array|@implode:', '}           {* Join array *}

{* Default values *}
{$var|default:"No value"}

{* Date formatting *}
{$date|date_format:"%Y-%m-%d"}   {* Format date *}

{* Math operations *}
{$number|math:'+':10}            {* Math operations *}

Register Custom Modifier:

<?php
// Register in your module
$xoopsTpl = new XoopsTpl();
$xoopsTpl->register_modifier('mymodifier', 'my_modifier_function');

function my_modifier_function($string) {
    return strtoupper($string);
}
?>

4. Cache Problems

Symptoms:

Template changes don’t appear
Old content still shows
Stale includes or resources

Solutions:

# Clear Smarty cache directories
rm -rf /path/to/xoops/xoops_data/caches/smarty_cache/*
rm -rf /path/to/xoops/xoops_data/caches/smarty_compile/*

# Clear specific module cache
rm -rf /path/to/xoops/xoops_data/caches/smarty_cache/modules/*

Clear Cache in Code:

<?php
// Clear all Smarty caches
$xoopsTpl = new XoopsTpl();
$xoopsTpl->clear_cache();
$xoopsTpl->clear_compiled_tpl();

// Clear specific template cache
$xoopsTpl->clear_cache('file:templates/page.html');

// Clear all cached files
require_once XOOPS_ROOT_PATH . '/class/xoopsfile.php';
$dh = opendir(XOOPS_CACHE_PATH . '/smarty_cache');
while (($file = readdir($dh)) !== false) {
    if (is_file(XOOPS_CACHE_PATH . '/smarty_cache/' . $file)) {
        unlink(XOOPS_CACHE_PATH . '/smarty_cache/' . $file);
    }
}
closedir($dh);
?>

5. Plugin Not Found Errors

Symptoms:

“Unknown modifier” or “Unknown plugin”
Custom functions don’t work
Compilation errors with plugins

Error Messages:

Fatal error: Call to undefined function smarty_modifier_custom
Unknown modifier 'myfunction'

Create Custom Plugin:

<?php
/**
 * Smarty {$var|custom} modifier plugin
 */
function smarty_modifier_custom($string, $param = '') {
    // Your custom code
    return strtoupper($string) . $param;
}
?>

Register Plugin:

<?php
// In your module's init code
$xoopsTpl = new XoopsTpl();

// Add plugin directory to Smarty
$xoopsTpl->addPluginDir(
    XOOPS_ROOT_PATH . '/modules/yourmodule/plugins'
);

// Or manually register
$xoopsTpl->register_modifier(
    'custom',
    'smarty_modifier_custom'
);
?>

Plugin Types:

<?php
function smarty_modifier_name($string) {
    return $string;
}

// Block plugin: block.name.php
function smarty_block_name($params, $content, &$smarty, &$repeat) {
    if (!isset($smarty->security_settings['IF_FUNCS'])) {
        $smarty->security_settings['IF_FUNCS'] = [];
    }
    return $content;
}

// Function plugin: function.name.php
function smarty_function_name($params, &$smarty) {
    return 'output';
}

// Filter plugin: filter.name.php
function smarty_filter_name($code, &$smarty) {
    return $code;
}
?>

6. Template Include/Extends Issues

Symptoms:

Included templates don’t load
Parent template not found
CSS/JS not loading

Error Messages:

Template file 'file:path/to/template.html' not found
Can't find template file 'header.html'

Correct Include Syntax:

{* Include template *}
{include file="file:templates/header.html"}

{* Include with variables *}
{include file="file:templates/header.html" title="My Page"}

{* Template inheritance *}
{extends file="file:templates/base.html"}

{* Named blocks *}
{block name="content"}
    Page content here
{/block}

{* Static resources *}
<link rel="stylesheet" href="{$xoops_url}/themes/{$xoops_theme}/style.css">
<script src="{$xoops_url}/modules/{$xoops_module_dir}/js/script.js"></script>

Check Template Path:

# Verify template file exists
ls -la /path/to/xoops/themes/mytheme/templates/
ls -la /path/to/xoops/modules/mymodule/templates/

# Check permissions
stat /path/to/xoops/themes/mytheme/templates/header.html

7. Variable Array/Object Access

Symptoms:

Can’t access array values
Object properties don’t display
Complex variables fail

Error Messages:

Undefined variable: user.profile.name

Correct Syntax:

{* Array access *}
{$array.key}                     {* Use . for keys *}
{$array['key']}
{$array.0}                       {* Numeric indexes *}
{$array.$variable_key}           {* Dynamic keys *}

{* Nested arrays *}
{$user.profile.name}
{$data.items.0.title}

{* Object properties *}
{$object.property}
{$object.method|escape}          {* Method calls *}

{* Safe access with isset *}
{if isset($array.key)}
    {$array.key}
{/if}

{* Check length *}
{if count($array) > 0}
    Items found
{/if}

8. Character Encoding Issues

Symptoms:

Garbled text in templates
Special characters display incorrectly
UTF-8 characters broken

Solutions:

Template File Encoding:

{* Set charset in meta tag *}
<meta charset="UTF-8">

{* Or in HTML head *}
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

{* Proper PHP declaration *}
header('Content-Type: text/html; charset=utf-8');

PHP Code:

<?php
// Set output encoding
header('Content-Type: text/html; charset=utf-8');

// Ensure database uses UTF-8
$conn = new mysqli('localhost', 'user', 'pass', 'db');
$conn->set_charset('utf8mb4');

// Or in SQL
SET NAMES utf8mb4;
SET CHARACTER SET utf8mb4;

// Assign data properly
$text = mb_convert_encoding($text, 'UTF-8', 'UTF-8');
$xoopsTpl->assign('text', $text);
?>

Debug Mode Configuration

Enable Template Debugging:

<?php
// In mainfile.php
define('XOOPS_DEBUG_LEVEL', 2);

// In Smarty configuration
$xoopsTpl->debugging = true;
$xoopsTpl->debug_tpl = SMARTY_DIR . 'debug.tpl';

// Or in module
$tpl = new XoopsTpl();
$tpl->debugging = true;
?>

Debug Console Output:

<?php
// Create modules/yourmodule/debug_smarty.php

require_once '../../mainfile.php';
require_once XOOPS_ROOT_PATH . '/class/smarty/Smarty.class.php';

$smarty = new Smarty();
$smarty->debugging = true;

// Check compiled template
$compiled_dir = $smarty->getCompileDir();
echo "<h1>Compiled Templates</h1>";
$files = glob($compiled_dir . '/*.php');
foreach ($files as $file) {
    echo "<p>" . basename($file) . "</p>";
}

// View compiled code
echo "<h1>Compiled Code</h1>";
echo "<pre>";
$latest = max(array_map('filemtime', $files));
foreach ($files as $file) {
    if (filemtime($file) == $latest) {
        echo htmlspecialchars(file_get_contents($file));
        break;
    }
}
echo "</pre>";
?>

Template Validation Checklist

graph TD
    A[Template Validation] --> B["1. Syntax Check"]
    A --> C["2. Variable Verification"]
    A --> D["3. Plugin Check"]
    A --> E["4. File Paths"]
    A --> F["5. Encoding"]
    A --> G["6. Cache"]

    B --> B1["✓ All braces matched"]
    B --> B2["✓ All tags closed"]
    B --> B3["✓ Proper syntax"]

    C --> C1["✓ Variables assigned"]
    C --> C2["✓ Correct property access"]
    C --> C3["✓ Default values set"]

    D --> D1["✓ Modifiers available"]
    D --> D2["✓ Plugins registered"]
    D --> D3["✓ Custom functions work"]

    E --> E1["✓ Relative paths correct"]
    E --> E2["✓ Files exist"]
    E --> E3["✓ Permissions correct"]

    F --> F1["✓ UTF-8 declared"]
    F --> F2["✓ HTML charset set"]
    F --> F3["✓ Database UTF-8"]

    G --> G1["✓ Cache cleared"]
    G --> G2["✓ Compiled fresh"]

Prevention & Best Practices

Enable debugging during development
Validate templates before deploying
Clear cache after changes
Use git to track template changes
Test in multiple browsers for encoding issues
Document custom plugins and modifiers
Use template inheritance for consistency

Smarty Debugging Guide
Smarty Templating
Enable Debug Mode
Theme FAQ

#xoops #troubleshooting #templates #smarty #debugging

Template Errors

Template Errors (Smarty Debugging)

Diagnostic Flowchart

Common Smarty Template Errors

1. Syntax Errors

Common Syntax Issues

2. Undefined Variable Errors

3. Missing or Incorrect Modifiers

4. Cache Problems

5. Plugin Not Found Errors

6. Template Include/Extends Issues

7. Variable Array/Object Access

8. Character Encoding Issues

Debug Mode Configuration

Template Validation Checklist

Prevention & Best Practices

Related Documentation