Template:TagCloud

/***
    USAGE:

    TagCloud() 
        build a tag cloud from a search query.


    PARAMETERS:

    query: str
        query string for selecting pages on which the tag could is built on (default: all pages)

    showCount: bool
        show number of occurrences of the tag (default: true)

    max: num
        limit tag cloud to top X tags (default: 10)

    order: str
        order tags by name or frequency (either "count" or "name"; default: "name)

    exclude: list
        list of tags to exclude from tag cloud

    fontSizeUnits: str
        display units for font size (default: "%")

    fontSizeMin: num
        smallest display font (default: 80)

    fontSizeMax: num
        largest display font size (default: 240)

    fontColorRMin: num
        lowest color value for red (default: 50)

    fontColorRMax: num
        highest color value for red (default: 50)

    fontColorGMin: num
        lowest color value for green (default: 200)

    fontColorGMax: num
        highest color value for green (default: 100)

    fontColorBMin: num
        lowest color value for blue (default: 50)

    fontColorBMax: num
        highest color value for blue (default: 50)

***/

var searchString = $query ?? ""; 
var hitShow = $showcount ?? true; 
var tagOrder = $order ?? "name";
var tagsLimit = $max ?? 0;
var tagsToExclude = $exclude ?? [ ];
var fontSizeUnits = $fontSizeUnits ?? "%"; 
var fontSizeMin = $fontSizeMin ?? 80; 
var fontSizeMax = $fontSizeMax ?? 240;
var fontColorRMin = $fontColorRMin ?? 236;
var fontColorRMax = $fontColorRMax ?? 224;
var fontColorGMin = $fontColorGMin ?? 95;
var fontColorGMax = $fontColorGMax ?? 10;
var fontColorBMin = $fontColorBMin ?? 11;
var fontColorBMax = $fontColorBMax ?? 27;

// TODO: figure out what this is supposed to do
if(__request.args.q) {
	<div id='tagResults'>
		<b> "Pages tagged with "; <u> __request.args.q; </u> " in this section "; </b>
		wiki.search("tag:"..string.quote(__request.args.q).."", 1000, "title", searchString);
		<a href=("Special:Tags?tag=" .. web.UriEncode(__request.args.q))> "See all pages tagged with " .. __request.args.q .. " across entire site"; </a> " »";
	
		var defined = __request.args.q;
		var found = wiki.getsearch("tag:" .. string.quote(defined), 1, _,"type:wiki");
		if(#found) {
			var def = found[0].tags[defined].definition;
			if(def) {
				<br />;
				<a href=(def.uri)> "Go to the " .. __request.args.q .. " definition page"; </a> " »";
			}
		}
	</div>
}

// convert list of excluded tags into a map (easier to check if tag is excluded)
let tagsToExclude = { (t): true foreach var t in tagsToExclude };

// compute map of tags based on search string and excluded tags (note: only pages have tags)
var myResults = wiki.getsearch(searchString, 1000, _, "type:wiki");
var tagMap = { };
foreach(var p in myResults, if __index < 250, var t in map.keys(p.tags ?? {}) where !tagsToExclude[t]) {
	var tag = string.startswith(t, "define:") ? string.substr(t, 7) : t;
	let tagMap ..= { (tag) : 1 + (tagMap[tag] ?? 0) };
}

// compute list of tags sorted by occurrence count
var tagListofMaps = [ { name: t, count: tagMap[t] } foreach var t in map.keys(tagMap) where tagMap[t] > 0 ];
var tagsTotal = #tagListofMaps;
let tagListofMaps = list.sort(tagListofMaps, 'count', true);
if ((tagsLimit > 0) && !__request.args.alltags) {
	let tagListofMaps = list.splice(tagListofMaps, tagsLimit);
}
var maxValue = tagListofMaps[0].count;
var minValue = tagListofMaps[#tagListofMaps-1].count;

// sort display of tags by frequency or name
let tagListofMaps = (tagOrder == "name" ? list.sort(tagListofMaps, 'name', false) : list.sort(tagListofMaps, 'count', true));

// emit tag cloud
<div id="tagCloud">
	<ul>
		foreach (var tm in tagListofMaps) {
			var tag = string.tocamelcase(tm.name);
			var tagURI = page.uri & { q: tag } .. '#tagResults';
			var count = tm.count;
			var weight = ( num.log(count) - num.log(minValue)) / ( num.log(maxValue) - num.log(minValue));
			var fontSize = fontSizeMin + num.round((fontSizeMax - fontSizeMin) * weight);
			var fontColorR = fontColorRMin + num.round((fontColorRMax - fontColorRMin) * weight);
			var fontColorG = fontColorGMin + num.round((fontColorGMax - fontColorGMin) * weight);
			var fontColorB = fontColorBMin + num.round((fontColorBMax - fontColorBMin) * weight);
			
			<li style=("padding-left: 1ex; display: inline-block; font-size:" .. fontSize .. fontSizeUnits)>
				var rgb = "rgb(" ..fontColorR .. "," .. fontColorG .. "," .. fontColorB .. ")";
				<a href=(tagURI) style=("color:" .. rgb .. ";")> tag </a>
				if(hitShow) {
					<sup style=("color:" .. rgb .. "; font-size: x-small;")>"(" .. count .. ")"</sup>
				}
			</li>		}

		if (!__request.args.alltags && (tagsLimit > 0) && (tagsTotal > tagsLimit)) {
			<li style="display:block">
				"Showing top " .. tagsLimit .. " tags. ";
				<a href=(page.uri & { alltags: _ } .. "#tagCloud")>"See all ".. tagsTotal .. " tags"</a>;
				" »";
			</li>
		}
	</ul>
</div>