mFilterSitemap

Snippet for generating an XML sitemap of filtered pages.

Description

mFilterSitemap creates an XML sitemap for filter virtual pages (SEO URLs). Works on the sitemap index principle — it only generates filter URLs that can be added to the main sitemap.

Features:

• Automatic detection of filter pages
• Combination limits to prevent "combinatorial explosion"
• Result caching
• Single and combined filter support
• Integration with MODX Scheduler for automatic generation

Parameters

Data source

Parameter	Default	Description
parents	auto	Resource IDs (comma-separated). Empty = all pages with filter sets
filterKeys	all	Filter keys to include (comma-separated)

Limits

Parameter	Default	Description
maxFilters	1	Max filters per URL (1 = single only)
maxValues	1	Max values per filter

SEO parameters

Parameter	Default	Description
priority	0.7	URL priority (0.0–1.0)
changefreq	weekly	Update frequency (always, hourly, daily, weekly, monthly, yearly, never)

Templates

Parameter	Default	Description
tpl	built-in	Single URL template
tplWrapper	built-in	urlset wrapper
sitemapSchema	http://www.sitemaps.org/schemas/sitemap/0.9	XML Schema

Output

Parameter	Default	Description
forceXML	true	Output XML header and exit
return	chunks	Return type: chunks (HTML) or data (array)

Caching

Parameter	Default	Description
cache	true	Enable caching
cacheTime	3600	Cache TTL (seconds)

Debug

Parameter	Default	Description
debug	false	Enable debug logs

Placeholders in templates

tpl (per URL)

Placeholder	Description
{$url}	Full page URL
{$lastmod}	Last modified date (ISO 8601)
{$changefreq}	Update frequency
{$priority}	Priority
{$filterKey}	Filter key
{$value}	Filter value
{$resourceId}	Base resource ID

tplWrapper

Placeholder	Description
{$output}	All URL elements
{$schema}	XML Schema
{$charset}	Charset
{$total}	Total URL count

Examples

Basic call (dedicated sitemap page)

Create resource /sitemap-filters.xml with template:

{'!mFilterSitemap' | snippet}

Specific filters only

{'!mFilterSitemap' | snippet: [
    'filterKeys' => 'color,size,brand'
]}

Two-filter combinations

{'!mFilterSitemap' | snippet: [
    'maxFilters' => 2,
    'priority' => '0.6'
]}

Warning: With many values this can produce a very large number of URLs!

For a specific category

{'!mFilterSitemap' | snippet: [
    'parents' => '5,10,15',
    'filterKeys' => 'color,brand'
]}

Without auto XML output

{set $sitemapXml = '!mFilterSitemap' | snippet: [
    'forceXML' => false
]}

{* Can process or save *}
{$sitemapXml}

Get data as array

{set $urls = '!mFilterSitemap' | snippet: [
    'return' => 'data',
    'forceXML' => false
]}

{* urls is array of data *}
Total URLs: {$urls | count}

Custom URL template

{'!mFilterSitemap' | snippet: [
    'tpl' => '@INLINE <url>
    <loc>{$url}</loc>
    <lastmod>{$lastmod}</lastmod>
    <changefreq>{$changefreq}</changefreq>
    <priority>{$priority}</priority>
    <xhtml:link rel="alternate" hreflang="en" href="{$url}"/>
</url>'
]}

Scheduler task

mFilter includes a task for automatic sitemap generation via MODX Scheduler.

Setup

1. Ensure Scheduler is installed
2. Task mfl_generate_sitemap is created automatically
3. Configure schedule in Scheduler manager

Task parameters

{
    "parents": "",
    "filterKeys": "",
    "maxFilters": 1,
    "priority": "0.7",
    "changefreq": "weekly",
    "outputFile": "assets/sitemap-filters.xml"
}

Manual run

$scheduler = $modx->services->get('scheduler');
$task = $scheduler->getTask('mfilter', 'mfl_generate_sitemap');
$task->schedule('+0 seconds');

robots.txt integration

Sitemap: https://example.com/sitemap.xml
Sitemap: https://example.com/sitemap-filters.xml

pdoSitemap integration

If you use pdoSitemap for the main sitemap, create a separate resource for filters:

/sitemap.xml          — pdoSitemap (main pages)
/sitemap-filters.xml  — mFilterSitemap (filters)
/sitemap-index.xml    — index file

sitemap-index.xml

<?xml version="1.0" encoding="UTF-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
    <sitemap>
        <loc>https://example.com/sitemap.xml</loc>
    </sitemap>
    <sitemap>
        <loc>https://example.com/sitemap-filters.xml</loc>
    </sitemap>
</sitemapindex>

Recommendations

URL count

Google recommends no more than 50,000 URLs per sitemap file. For large catalogs:

• Keep maxFilters at 1
• Split by category (use parents)
• Exclude rare filters

Priority

Suggested values:

• Home: 1.0
• Categories: 0.8
• Products: 0.6
• Filters: 0.5–0.7

Update frequency

For filters, weekly or monthly is usually enough, since structure changes infrequently.