What's the best way to generate a tag cloud from an array using h1 through h6 for sizing?

dubayou_146637 0
Viewed 9120

I have the following arrays:

$artist = array("the roots", "michael jackson", "billy idol", "more", "and more", "and_YET_MORE");
$count = array(5, 3, 9, 1, 1, 3);

I want to generate a tag cloud that will have artists with a higher number in $count enclosed in h6 tags and the lowest enclosed h1 tags.

tag-cloud arrays php
8 Answers

Off the top of my head...

$artist = array("the roots","michael jackson","billy idol","more","and more","and_YET_MORE");
$count = array(5,3,9,1,1,3);
$highest = max($count);
for (int $x = 0; $x < count($artist); $x++)
{
    $normalized = $count[$x] / $highest;
    $heading = ceil($normalized * 6); // 6 heading types
    echo "<h".$heading.">".$artist[$x]."</h".$heading.">";
}
user_550

Perhaps this is a little academic and off topic but hX tags are probably not the best choice for a tag cloud for reasons of document structure and all that sort of thing.

Maybe spans or an ol with appropriate class attributes (plus some CSS)?

user_1990

Have used this snippet for a while, credit is prism-perfect.net. Doesn't use H tags though

<div id="tags">
    <div class="title">Popular Searches</div>
    <?php
        // Snippet taken from [prism-perfect.net]

        include "/path/to/public_html/search/settings/database.php";
        include "/path/to/public_html/search/settings/conf.php";

        $query = "SELECT query AS tag, COUNT(*) AS quantity
        FROM sphider_query_log
        WHERE results > 0
        GROUP BY query
        ORDER BY query ASC
        LIMIT 10";

        $result = mysql_query($query) or die(mysql_error());

        while ($row = mysql_fetch_array($result)) {

            $tags[$row['tag']] = $row['quantity'];
        }

        // change these font sizes if you will
        $max_size = 30; // max font size in %
        $min_size = 11; // min font size in %

        // get the largest and smallest array values
        $max_qty = max(array_values($tags));
        $min_qty = min(array_values($tags));

        // find the range of values
        $spread = $max_qty - $min_qty;
        if (0 == $spread) { // we don't want to divide by zero
            $spread = 1;
        }

        // determine the font-size increment
        // this is the increase per tag quantity (times used)
        $step = ($max_size - $min_size)/($spread);

        // loop through our tag array
        foreach ($tags as $key => $value) {

            // calculate CSS font-size
            // find the $value in excess of $min_qty
            // multiply by the font-size increment ($size)
            // and add the $min_size set above
            $size = $min_size + (($value - $min_qty) * $step);
            // uncomment if you want sizes in whole %:
            // $size = ceil($size);

            // you'll need to put the link destination in place of the /search/search.php...
            // (assuming your tag links to some sort of details page)
            echo '<a href="/search/search.php?query='.$key.'&search=1" style="font-size: '.$size.'px"';
            // perhaps adjust this title attribute for the things that are tagged
            echo ' title="'.$value.' things tagged with '.$key.'"';
            echo '>'.$key.'</a> ';
            // notice the space at the end of the link
        }
    ?>
</div>
Admin1

@Ryan

That's correct but it actually makes the tags with the least number, larger. This code has been tested:

$artist = array("the roots","michael jackson","billy idol","more","and more","and_YET_MORE");
$count = array(5,3,9,1,1,3);
$highest = max($count);
for ($x = 0; $x < count($artist); $x++) {
    $normalized =  ($highest - $count[$x]+1) / $highest;
    $heading = ceil($normalized * 6); // 6 heading types
    echo "<h$heading>{$artist[$x]}</h$heading>";
}
user_400

As a helper in Rails:

def tag_cloud (strings, counts)
    max = counts.max
    strings.map { |a| "<span style='font-size:#{((counts[strings.index(a)] * 4.0)/max).ceil}em'>#{a}</span> "  }
end

Call this from the view:

<%= tag_cloud($artists, $counts) %>

This outputs <span style='font-size:_em'> elements in an array that will be converted to a string in the view to ultimately render like so:

<span style='font-size:3em'>the roots</span>
<span style='font-size:2em'>michael jackson</span> 
<span style='font-size:4em'>billy idol</span> 
<span style='font-size:1em'>more</span> 
<span style='font-size:1em'>and more</span> 
<span style='font-size:2em'>and_YET_MORE</span>

It would be better to have a class attribute and reference the classes in a style sheet as mentioned by Brendan above. Much better than using h1-h6 semantically and there's less style baggage with a <span>.

Admin1
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