I have a bunch of resources (about 200) each representing a house or flat for sale. They each have a TV which called “locTown”. Unsurprisingly, this TV stores which town the flat/house is located in.
On my home page I wanted to put a nice, clickable list of all the towns. I searched far and wide for a way to return only unique/distinct values of a TV (rather than a list which just repeated the same towns 20 or 30 times).
As I was using pdoTools I experimented a bit with the &where statement, tries to trick it into allow me to use a DISTINCT query but all to no avail. Thus began my quest to write a small utility snippet for pdoTools which does the job - and here it is:
<?php
/**
* pdoUnique snippet
*
* Usage:
* [[!pdoUnique?
* &parents=`2`
* &includeTVs=`locTown`
* &processTVs=`1`
* &uniqueField=`tv.locTown`
* &uniqueLimit=`8`
* &tpl=`@INLINE <li>[[+tv.locTown]]</li>`
* &limit=`0`
* ]]
*/
// Extract snippet properties
$uniqueField = $modx->getOption('uniqueField', $scriptProperties, '');
$uniqueLimit = (int) $modx->getOption('uniqueLimit', $scriptProperties, 0);
$tpl = $modx->getOption('tpl', $scriptProperties, '');
$tplWrapper = $modx->getOption('tplWrapper', $scriptProperties, '');
unset($scriptProperties['uniqueField'], $scriptProperties['uniqueLimit']);
// Enforce raw data return for further processing
$scriptProperties['return'] = 'data';
// Fetch data using pdoResources
$data = $modx->runSnippet('pdoResources', $scriptProperties);
// Ensure data is an array
if (!is_array($data)) {
return 'Error: pdoResources did not return an array. Output: ' . print_r($data, true);
}
// Deduplicate results based on uniqueField
if (!empty($uniqueField)) {
$seen = [];
$rows = array_filter($data, function ($row) use ($uniqueField, &$seen, $uniqueLimit) {
$value = $row[$uniqueField] ?? null;
if ($value === null || in_array($value, $seen, true)) {
return false;
}
$seen[] = $value;
return $uniqueLimit <= 0 || count($seen) <= $uniqueLimit;
});
} else {
$rows = $data;
}
// Load pdoTools for chunk rendering
/** @var pdoTools $pdoTools */
$pdoTools = $modx->getService('pdoTools');
// Render output
$output = '';
foreach ($rows as $row) {
$output .= empty($tpl)
? "<pre>" . print_r($row, true) . "</pre>\n"
: $pdoTools->getChunk($tpl, $row);
}
return $output;
Basically, it calls pdoResources and then sends the results though a loop which filters out the duplicates based on the TV field you specify, then returns what’s left over into whatever chunk you want.
Note that this is made somewhat easier by an under-documented feature in pdoResources called &return=data which will return the output of your snippet call as a raw php array - useful when you want to manipulate this output with another snippet.
Not the prettiest or most elegant code, but it works pretty well for me so far.
Happy to hear feedback and hints on how to improve it. Thx.
But appreciate the suggestion.