the LUX Web Engine: a simple not-a-blog thing

LUX Web Engine - index.php

<?php

    // LUX Web Engine - created bespoke for SnugglePilot.com.
    // Created by Andy Moore. Run this code at your own risk. "Whatever" license I guess.
    // Changelog/instructions: http://snugglepilot.com/?p=lux%20web%20engine

    // v8 - Updated July 2nd, 2018

    // ##############
    // Configuration:
    // ##############


    $contentPath = "content/";  // relative folder to your content (text) files
    $imagePath = "images/";     // relative folder to your image files
    $defaultFile = "default";   // what content (text) file to show if no other is specified
    $failFile = "404";          // what content (text) file to show if something was specified, but doesn't exist
    $suffix = ".txt";           // what extension your content files have.

    // so, eg, "content/default.txt" will be what is shown when you first load this page.

    // Patterns are regular-expressions. Try using this site to make your own: https://regexr.com/
    $linkPattern = "/\[[\w\d -'\|]+\]/";        // What we turn into links. default: [Link] or [real file|Label]
    $imagePattern = "/\[[\w\d]+\.[\w\d]+\]/";   // What we turn into images. default: [image.png]
    $boldPattern = "/\*.*?\*/";                 // What we turn bold. default: *bold*
    $italicsPattern = "/(?:^| )_.*?_/";         // What we turn into italics. default: _italics_
    $hrPattern = "/(?:[\r\n])---[\r\n]/";       // What we turn into an <HR>. default: --- (alone on a line)
    $quotePattern = "/^> .*$/m";                // What we turn into a quote. default: >

    $bulletedListCharacter = "*";               // What we use to indicate a bulleted list.
    $numberedListCharacter = "#";               // What we use to indicate a numbered list.
    $lineBreakListTolerance = 1;                // How many line breaks starts a new list?
    $linkSplitCharacter = "|";                  // What we use to split a link description, eg [link|displayed text]
    $latestEntryKeyword = "<<LATEST_ENTRIES>>"; // What we turn into a list of recently updated things.
    $numberOfLatestEntries = 5;                 // How many latest entries to display.


    // #######################################################
    // Not much to edit after this, unless you really want to.
    // #######################################################

    // Global variables. We don't use these in the content; they are available if you want to include
    // them in the header or the footer.

    $pageTitle = "";            // Populated by ParseContent
    $pageModifyDate = "";       // Populated by ParseContent

    $content = ParseContent();  // Generate content and populate the above global vars.

    // This actually renders the page:
    include("header.php");  // Just HTML, put what you like here.
    echo $content;
    include("footer.php");  // Just HTML, put what you like here.


    // #######################################################


    // This is the heavy-lifting main-parser for the site.
    function ParseContent() {
        global $latestEntryKeyword, $numberOfLatestEntries, $bulletedListCharacter, $numberedListCharacter;

        // Fetch appropriate content.
        $content = GetRelevantContent();

        // Parse [Links] to other content.
        // Eg, if you write [Link] it will instead display this as an <a href="link.txt">Link</a>.
        // Will turn spaces into underscores automatically. make sure your content files are all lower case.
        $content = ParseLinkTags($content);

        // Parse [image.png] references:
        // Same as links but shows images instead. make sure they are lower case.
        $content = ParseImageTags($content);

        // Generate latest entries lists with magic keyword:
        // (this is an unstyled hack right now but it works. Just put the magic word in your document and it'll be fine)
        if (strpos($content, $latestEntryKeyword) !== false) {
            $content = str_replace($latestEntryKeyword, GetLatestEntries($numberOfLatestEntries), $content);
        }

        // Parse formatting things:
        $content = ParseList($content, $bulletedListCharacter, "ul"); // lists should come before bold because they use the same character.
        $content = ParseList($content, $numberedListCharacter, "ol");
        $content = ParseQuotes($content);
        $content = ParseBoldTags($content);
        $content = ParseItalicsTags($content);
        $content = ParseHRTags($content);

        // This converts newline characters to <BR> characters:
        $content = nl2br($content);

        return $content;
    }

    // This checks the URL and fetches the relevant content.
    function GetRelevantContent() {
        global $contentPath, $suffix, $failFile, $defaultFile, $pageTitle, $pageModifyDate;

        if (isset($_GET["p"])) {
            // A specific page has been requested:
            $contentFile = $_GET["p"];
            $contentFile = str_replace("%20", " ", $contentFile);
            if ($contentFile != $defaultFile) {
                $pageTitle = $contentFile;                
            }
        } else {
            // Falling back to default file:
            $contentFile = $defaultFile;
        }
        $fileFullPath = $contentPath . $contentFile . $suffix;
        if (!file_exists($fileFullPath)) {
            // Show error file - invalid link:
            $fileFullPath = $contentPath . $failFile . $suffix;
            $pageTitle = $failFile;

            if (!file_exists($fileFullPath)) {
                // Great, the error file doesn't exist.
                http_response_code(404);
                echo "<html><head><title>404</title></head><body>Site owner hasn't set up a 404 page.</body></html>";
                die();  
            }
        }

        $pageModifyDate = TimeElapsed("@".filemtime($fileFullPath));

        return file_get_contents($fileFullPath);
    }

    function ParseQuotes($content) {
        global $quotePattern;
        $matches = GetPatternMatch($content, $quotePattern);
        for ($i = 0; $i < count($matches); $i++) {
            // strip out the tag
            $targetPhrase = substr($matches[$i], 1);
            $targetPhrase = "<blockquote>".$targetPhrase."</blockquote>";
            $content = str_replace($matches[$i], $targetPhrase, $content);
        }
        return $content;
    }

    function ParseBoldTags($content) {
        global $boldPattern;
        $matches = GetPatternMatch($content, $boldPattern);
        for ($i = 0; $i < count($matches); $i++) {
            // strip out the tag
            $targetPhrase = substr($matches[$i], 1, strlen($matches[$i])-2);
            $targetPhrase = "<strong>".$targetPhrase."</strong>";
            $content = str_replace($matches[$i], $targetPhrase, $content);
        }
        return $content;
    }

    function ParseItalicsTags($content) {
        global $italicsPattern;
        $matches = GetPatternMatch($content, $italicsPattern);
        for ($i = 0; $i < count($matches); $i++) {
            // strip out the tag
            $targetPhrase = substr($matches[$i], 2, strlen($matches[$i])-3);
            $targetPhrase = " <em>".$targetPhrase."</em>";
            $content = str_replace($matches[$i], $targetPhrase, $content);
        }
        return $content;
    }

    function ParseHRTags($content) {
        global $hrPattern;
        $matches = GetPatternMatch($content, $hrPattern);
        for ($i = 0; $i < count($matches); $i++) {
            $targetPhrase = "<br/><hr/>";
            $content = str_replace($matches[$i], $targetPhrase, $content);
        }
        return $content;
    }

    function ParseList($content, $listCharacter, $listType) {
        global $lineBreakListTolerance;
        // grabbed this from: https://stackoverflow.com/questions/2344563/a-regex-that-converts-text-lists-to-html-in-php
        $listPattern = "/^\\".$listCharacter." .*$/m";

        $matches = GetPatternMatch($content, $listPattern);
        for ($i = 0; $i < count($matches); $i++) {
            // strip out the tag
            $targetPhrase = substr($matches[$i], 2);
            // This puts each dot in it's own list:
            $targetPhrase = "<".$listType."><li>".$targetPhrase."</li></".$listType.">";
            $content = str_replace($matches[$i], $targetPhrase, $content);
        }

        // This removes double </ul><ul> tags to simplify things:
        // {0,2} for the \n tag would be better but that doesn't properly capture mushed together html :/
        $content = preg_replace("/(\<\/".$listType."\>\n{1,".$lineBreakListTolerance."}(.*)\<".$listType."\>*)+/","", $content);
        return $content;
    }

    // Just a loop to fire GetTextLink a whole bunch.
    function ParseLinkTags($content) {
        global $linkPattern, $linkSplitCharacter;

        $matches = GetPatternMatch($content, $linkPattern);
        for ($i = 0; $i < count($matches); $i++) {
            // strip out the braces
            $reference = substr($matches[$i], 1, strlen($matches[$i])-2);
            $label = $reference;
            // check for split links (eg: [real link|displayed text])
            $split = explode($linkSplitCharacter, $reference, 2);
            if (count($split) == 2) {
                if (strlen($split[0]) <= 0) {
                    // We can't make a link if the pre-split area is size zero. eg: [|display text]
                    return $content;
                } else {
                    // in case the last half of the split fails, let's at least trim the pipe out.
                    $reference = $split[0];
                }
                if (strlen($split[1]) > 0) {
                    // We only use the label if it has content. [realLink|] will pretend you didn't use a pipe.
                    $label = $split[1];
                }
            } 
            $link = GetTextLink($reference, $label);
            $content = str_replace($matches[$i], $link, $content);
        }
        return $content;
    }

    // This converts a word to a text link from your content folder.
    function GetTextLink($for, $label) {
        $formatted = trim(strtolower($for));
        $replacedSpaces = str_replace(" ", "%20", $formatted);
        $link = "<a href='?p=".$replacedSpaces."'>".$label."</a>";
        return $link;
    }

    // Just a loop to fire GetImageTag a whole bunch.
    function ParseImageTags($content) {
        global $imagePattern;

        $matches = GetPatternMatch($content, $imagePattern);
        for ($i = 0; $i < count($matches); $i++) {
            $content = str_replace($matches[$i], GetImageTag($matches[$i]), $content);
        }
        return $content;
    }

    // This converts a filename to a proper image link.
    function GetImageTag($filename) {
        global $imagePath;

        $reference = substr($filename, 1, strlen($filename)-2);
        $reference = strtolower($reference);
        return "<img src='".$imagePath.$reference."'/>";
    }

    // HTML-formats a nice list of the latest N updated content files.
    function GetLatestEntries($listLength) {
        global $contentPath, $suffix;

        $files = glob($contentPath."*".$suffix);
        $files = array_combine($files, array_map("filemtime", $files));
        arsort($files);
        if ($listLength > count($files)) {
            $listLength = count($files);
        }

        $entries = "<hr>";
        for ($i = 0; $i < $listLength; $i++) {
            $flatName = basename(key($files));
            $flatName = str_replace($suffix, "", $flatName);
            $entries .= "<br>";
            $entries .= GetTextLink($flatName, $flatName);
            $entries .= " (".TimeElapsed("@".current($files)).")";
            next($files);
        }
        $entries .= "<br><br><hr>";
        return $entries;
    }

    // Shortcut to fetch the regex pa ttern.
    function GetPatternMatch($content, $pattern) {
        preg_match_all($pattern, $content, $matches);
        return $matches[0];
    }

    // Stole this from stack overflow to make nice dates.
    // Will show "updated 10 seconds ago" or "updated a year ago".
    function TimeElapsed($datetime, $full = false) {
        $now = new DateTime;
        $ago = new DateTime($datetime);
        $diff = $now->diff($ago);

        $diff->w = floor($diff->d / 7);
        $diff->d -= $diff->w * 7;

        $string = array(
            'y' => 'year',
            'm' => 'month',
            'w' => 'week',
            'd' => 'day',
            'h' => 'hour',
            'i' => 'minute',
            's' => 'second',
        );
        foreach ($string as $k => &$v) {
            if ($diff->$k) {
                $v = $diff->$k . ' ' . $v . ($diff->$k > 1 ? 's' : '');
            } else {
                unset($string[$k]);
            }
        }

        if (!$full) $string = array_slice($string, 0, 1);
        return $string ? implode(', ', $string) . ' ago' : 'just now';
    }
?>