Create an index/linklist of all used image tags
Problem
You need to collect all tags from image fields and create a link list to then filter pages with images that have the selected tag.
Solution
(See inline comments:)
/**
* collect all tags
* ======================================
*/
$alltags = array(); // container
$use_urlsegments = false;
// find all pages that have images with tags
$parray = $pages->find("template=basic-page|gallery, images.tags!=''");
// loop pages found and collect tags from images
foreach($parray as $p) {
// find all images that have no empty tags, yeah you can
// also use find on Pagefiles array!
$images = $p->images->find("tags!=''");
// loop them and add tags to array
foreach($images as $im) {
$tags = $im->tags;
// convert "," and "|" to space and create array using explode
if(strpos($tags, ',') !== false) $tags = str_replace(',', ' ', $tags);
if(strpos($tags, '|') !== false) $tags = str_replace('|', ' ', $tags);
$tags = explode(' ', $tags);
// convert tag value to a page name using beautifyer, ü => ue, ö => oe
// since special chars are not allowed in PW urls
foreach($tags as $tag) {
$alltags[$sanitizer->pageName($tag, Sanitizer::translate)] = $tag;
}
}
}
/**
* generate links with tags as urlsegment
* ======================================
*/
// make the array unique and create a tags nav from it
// add tags to the url of the page to later read it and
// render a list of pages
echo "<ul>";
foreach(array_unique($alltags) as $key => $tag) {
if($use_urlsegments) {
echo "<li><a href='{$page->url}$key'>$tag</a></li>";
} else {
echo "<li><a href='{$page->url}?tag=$tag'>$tag</a></li>";
}
}
echo "</ul>";
/**
* find all pages with the supplied tag
* ======================================
*/
// enable url segments on the template if using url segments
if($input->urlSegment1 || $input->get->tag){
if($input->urlSegment1) {
$tagvalue = $input->urlSegment1;
// get the original tag value text from the cached array
$tagvalue = $alltags[$tagvalue];
}
if($input->get->tag) {
$tagvalue = $sanitizer->selectorValue($input->get->tag);
}
// find pages with images having the requested tag
$pa = $pages->find("images.tags~='$tagvalue'");
if(count($pa)) {
echo "<h2>Pages found</h2>";
echo "<ul>";
foreach($pa as $p) echo "<li><a href='$p->url'>$p->title</a></li>";
echo "</ul>";
}
}