personal-website/docs/www/blog/generatearticle.php

<?php
$COMMONS = $_SERVER['DOCUMENT_ROOT'] . "/../common";

include_once($COMMONS."/header.php");
include_once("blogpost.php");
include_once("blogpostcomment.php");

/**
 * Send a comment to the database.
 * If the poster is not signed in, send "NULL" (as a string) as the $posterID
 * The same goes for $parentId (that is the parent comment,
 * if this one is a response)
 * Returns: GUID PK of the newly added comment.
 */
function send_comment($conn, $blogId, $posterId, $content, $parentId) {
	// If content is empty, do not post
	if(empty($content)) {
		return "";
	}

	// Get a uuid for the comment
	$stmt = $conn->prepare("SELECT UUID()");
	$stmt->execute();
	$result = $stmt->fetch(PDO::FETCH_ASSOC);
	$uuid = $result["UUID()"];

	// Prepare the statemtnt
	$stmt = $conn->prepare("INSERT INTO blogpost_comments
		( comment_id,  parent_id,  blogpost_id,  poster_id,  content) VALUES
		(:comment_id, :parent_id, :blogpost_id, :poster_id, :content);");

	// Bind all the parameters
	$stmt->bindValue(":comment_id", $uuid, PDO::PARAM_STR);
	$stmt->bindValue(":parent_id", $parentId == "NULL"
		? NULL : $parentId, PDO::PARAM_STR);
	$stmt->bindValue(":blogpost_id", $blogId, PDO::PARAM_STR);
	$stmt->bindValue(":poster_id", $posterId == "NULL"
		? NULL : $posterId, PDO::PARAM_STR);
	$stmt->bindValue(":content", $content, PDO::PARAM_STR);

	// Execute the statement
	$stmt->execute();

	return $uuid;
}

/**
 * Load comments under a given blog.
 * Returns array of BlogpostComment objects.
 */
function load_comments($conn, $blogId, $blogAddress) {
	// Prepare new statement for selecting all the child comments.
	$stmt = $conn->prepare("SELECT comment_id, poster_id, timestamp,
		content FROM blogpost_comments WHERE blogpost_id = :blogpost_id
		AND parent_id IS NULL ORDER BY timestamp ASC;");

	// Bind and execute the comment select
	$stmt->bindParam(":blogpost_id", $blogId);
	$stmt->execute();

	// Fetch the comments
	$results_arr = $stmt->fetchall(PDO::FETCH_ASSOC);
	$comments_arr = [];

	// Prepare comment author selection statement
	$stmt = $conn->prepare("SELECT username FROM users WHERE
		user_id = :user_id;");

	// Recursively fetch all the child comments
	for($i = 0; $i < count($results_arr); $i++) {
		$com = $results_arr[$i];

		// If comment has a registered author, fetch their name
		if($com["poster_id"]) {
			$stmt->bindParam(":user_id", $com["poster_id"]);

			$stmt->execute();

			$result = $stmt->fetch(PDO::FETCH_ASSOC);

			// If user was erased from database, set name to [Deleted]
			if(!$result) {
				$username = "[Deleted]";
			}
			else {
				$username = $result["username"];
			}
		}
		else {
			$username = "[Guest]";
		}

		$commentObj = new BlogpostComment($com["comment_id"], $com["poster_id"],
			$username, $blogId, $blogAddress, $com["timestamp"],
			$com["content"], NULL);
		$commentObj->load_children($conn);
		$comments_arr[] = $commentObj;
	}

	return $comments_arr;
}

/**
 * Load info about the blog with a given guid and return corresponding
 * Blogpost object. NULL if blog couldn't be loaded.
 */
function load_blog($conn, $blogId){
	// Prepare and bind statement for gathering blogpost info
	$stmt = $conn->prepare("SELECT readable_address, title, content,
		date_posted, date_edited FROM blogposts WHERE
		blogpost_id = :blogpost_id;");
	$stmt->bindParam(":blogpost_id", $blogId);

	// Execute the statement
	$stmt->execute();

	// Fetch the blogpost
	$result = $stmt->fetch(PDO::FETCH_ASSOC);

	// If no post with given guid was found,
	// there is no information to gather, return.
	if(!$result){
		return null;
	}

	// Prepare new statement for selecting the tags for a given blogpost
	$stmt = $conn->prepare("SELECT name, color FROM
		blogpost_tags INNER JOIN blogpost_has_tag ON
		blogpost_tags.tag_id = blogpost_has_tag.tag_id WHERE
		blogpost_id = :blogpost_id;");

	// Bind and execute the tag select
	$stmt->bindParam(":blogpost_id", $blogId);
	$stmt->execute();

	// Fetch the tags
	$tags_arr = $stmt->fetchall(PDO::FETCH_ASSOC);

	// Set the variables
	$blogTitle = $result["title"];
	$blogAddress = $result["readable_address"];
	$blogContent = $result["content"];
	$datePosted = $result["date_posted"];
	$dateEdited = $result["date_edited"];
	$tags = $tags_arr;
	$comments = load_comments($conn, $blogId, $blogAddress);

	return new Blogpost($blogId, $blogAddress, $blogTitle, $blogContent,
						$datePosted, $dateEdited, $tags, $comments);
}

// Check DB connection
if($conn == null){
	header($_SERVER["SERVER_PROTOCOL"]." 503 Service Unavailable", true, 503);
	include_once($_SERVER["DOCUMENT_ROOT"]."/errors/503.php");
	die();
}

// If a human-readable address was provided, extract appropriate id.
if(isset($_POST["address"])) {
	$blogAddr = sanitize_input($_POST["address"]);

	// Prepare and bind statement for gathering blogpost address
	$stmt = $conn->prepare("SELECT blogpost_id
		FROM blogposts WHERE readable_address = :readable_address;");
	$stmt->bindParam(":readable_address", $blogAddr);

	// Execute the statement
	$stmt->execute();

	// Fetch the blogpost
	$result = $stmt->fetch(PDO::FETCH_ASSOC);

	// If post with given address was found, set the $blogId var.
	if($result){
		$blogId = sanitize_input($result["blogpost_id"]);
	}
}

// Attempt to load the blogpost
$blogPost = load_blog($conn, $blogId);

// If blogpost could not be retieved, display warning and die.
if(!$blogPost) {
	header($_SERVER["SERVER_PROTOCOL"]." 404 Not Foud", true, 404);
	die();
}

// Try to open the file to which to render the blogpost.
if (!($fp = fopen("article/".$blogPost->address.".php", 'w'))) {
	header($_SERVER["SERVER_PROTOCOL"]." 500 Could not open file for writing",
		true, 505);
	echo "fail";
	die();
}

fprintf($fp,
"<?php
include_once(\"%s\");
display_header(\"%s\");
echo \"%s\";
?>
<hr style=\"border-style: solid;\">
<article>
	<h2> Comments: </h2>
	<form method=\"post\" action=\"%s\">
		<input type=\"hidden\" name=\"blogpost_id\" value=\"%s\">
		<input type=\"hidden\" name=\"address\" value=\"%s\">
		<label for=\"comment_entry\">Write a comment (<?php
echo isset(\$_SESSION[\"current_user\"]) ?
	\$_SESSION[\"current_user\"]->user_name:
	\"Guest\";
?>
):</label>
		<div class=\"centered-container\">
			<textarea name=\"comment_entry\" class=\"comment-box\"
				tabindex=\"1\"></textarea>
		</div>
		<input name=\"submit\" type=\"submit\" tabindex=\"2\"
		value=\"Send\">
	</form>
</article>
<?php
echo \"%s\";
include_once(\"%s\");
?>
",
	$COMMONS."/header.php",
	$blogPost->title,
	addslashes($blogPost->display_article()),
	"SEND_COMMAND_ACTION",
	$blogPost->blogId,
	$blogPost->address,
	addslashes($blogPost->display_comments()),
	$COMMONS."/footer.php");
?>