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

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

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

// If the user does not have the 1000 0000 permission,
// throw a 403: Forbidden error.
if (!isset($_COOKIE["PHPSESSID"]) ||
	!(bool)($_SESSION["current_user"]->permissions & 128)) {
	header($_SERVER["SERVER_PROTOCOL"]." 403 Forbidden", true, 403);
	include_once($_SERVER["DOCUMENT_ROOT"]."/errors/403.php");
	include_once($COMMONS."/footer.php");
	die();
}

/**
 * Generate a feed.atom file for use by atom/rss readers.
 */
function generate_atom_feed($conn) {
	if (!($fp = fopen('feed.atom', 'w'))) {
		return;
	}

	// Prepare statement for selecting all the blogposts
	$stmt = $conn->prepare("SELECT blogpost_id, readable_address, title,
		abstract, content, date_posted, date_edited FROM blogposts ORDER BY
		date_posted DESC LIMIT 15;");

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

	// Prepare new statement for selecting the tags for a given blogpost
	$blogposts_arr = $stmt->fetchall(PDO::FETCH_ASSOC);

	fprintf($fp, "<?xml version=\"1.0\" encoding=\"utf-8\"?>
	<feed xmlns=\"http://www.w3.org/2005/Atom\">
	<title>Zdenek Borovec blog</title>
	<link href=\"https://www.zdenekborovec.cz/blog/\"/>
	<updated>%s</updated>
	<author>
	<name>Zdenek Borovec</name>
	</author>
	<id>https://www.zenekborovec.cz/blog/</id>
	", date("Y-m-d\TH:i:s\Z"));

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

	// Go through all the blogposts, fetch their tags and display them
	for($i=0; $i < count($blogposts_arr); $i++) {
		// Get info for the current blog
		$blog = $blogposts_arr[$i];

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

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

		$categoryStr = "";

		for($j=0; $j < count($tags_arr); $j++) {
			$tag = $tags_arr[$j];
			$categoryStr = $categoryStr."<category term=\"".
				$tag["name"]."\"/>";
		}

		if(is_null($blog["readable_address"])) {
			fprintf($fp, "
			<entry>
			<title>%s</title>
			%s
			<link href=
				\"https://www.zdenekborovec.cz/blog/article/?blogpost_id=%s\"/>
			<id>urn:uuid:%s</id>
			<published>%s</published>
			<updated>%s</updated>
			<summary>%s</summary>
			<content type=\"html\">
			%s
			</content>
			</entry>", $blog["title"], $categoryStr, $blog["blogpost_id"],
			$blog["blogpost_id"],
			date("Y-m-d\TH:i:s\Z", strtotime($blog["date_posted"])),
			date("Y-m-d\TH:i:s\Z", strtotime($blog["date_edited"])),
			$blog["abstract"], sanitize_input($blog["content"]));
		}
		else {
			fprintf($fp, "
			<entry>
			<title>%s</title>
			%s
			<link href=
				\"https://www.zdenekborovec.cz/blog/article/?address=%s\"/>
			<id>urn:uuid:%s</id>
			<published>%s</published>
			<updated>%s</updated>
			<summary>%s</summary>
			<content type=\"html\">
			%s
			</content>
			</entry>", $blog["title"], $categoryStr, $blog["readable_address"],
			$blog["blogpost_id"],
			date("Y-m-d\TH:i:s\Z", strtotime($blog["date_posted"])),
			date("Y-m-d\TH:i:s\Z", strtotime($blog["date_edited"])),
			$blog["abstract"], sanitize_input($blog["content"]));
		}
	}
	fprintf($fp, "</feed>");
}

/**
 * Explode the tag string into separate tags, if they exist,
 * attach them to the article.
 */
function add_tags_to_blogpost($conn, $blogpost_id, $tagStr) {
	// Get array of all the tags.
	$tagArr = explode(" ", $tagStr);

	// Prepare array for storing tag ids
	$tagIdArr = [];

	// Prepare statement to select id of a tag with given name
	$stmt = $conn->prepare("SELECT tag_id FROM blogpost_tags
		WHERE name = :name");

	// Go through all the tag names and get their ids
	foreach ($tagArr as $tagName) {
		// Bind, execute and fetch the command
		$stmt->bindParam(":name", $tagName);
		$stmt->execute();
		$result = $stmt->fetch(PDO::FETCH_ASSOC);

		// If we got a result, add it to the found ids.
		if($result) {
			$tagIdArr[] = $result["tag_id"];
		}
	}

	// Prepare the statement to add tag to blogpost and bind blogpost_id
	$stmt = $conn->prepare("INSERT INTO blogpost_has_tag (blogpost_id, tag_id)
		VALUES (:blogpost_id, :tag_id)");
	$stmt->bindParam(":blogpost_id", $blogpost_id);

	// Go through the found ids and insert them
	foreach ($tagIdArr as $tagId) {
		$stmt->bindParam(":tag_id", $tagId);
		$stmt->execute();
	}
}

/**
 * Delete all blogpost-tag relations involving the given blogpost.
 * @param $conn			Active Mysql connection.
 * @param $blogpost_id	GUID of the edited blogpost.
 */
function remove_blogpost_tags($conn, $blogpost_id) {
	// Prepare, bind and execute the delete statement
	$stmt = $conn->prepare("DELETE FROM blogpost_has_tag
		WHERE blogpost_id = :blogpost_id;");
	$stmt->bindParam(":blogpost_id", $blogpost_id);
	$stmt->execute();
}

/**
 * Publish a new blogpost and add the specified tags to it..
 * @param $conn				Active Mysql connection.
 * @param $blogpost_addr	Human-readable address of the edited blogpost.
 * @param $title			Title for the blogpost.
 * @param $tagStr			String with all the tags for the blogpost
 *							(space-separated).
 * @param $abstract			Abstract for the article.
 * @param $content			Content of the article.
 * @returns	The guid of the newly generated blogpost.
 */
function publish_blogpost($conn, $blogpost_addr, $title, $tagStr, $abstract,
	$content) {
	// Get an ID for the blogpost
	$stmt = $conn->prepare("SELECT UUID()");
	$stmt->execute();
	$result = $stmt->fetch(PDO::FETCH_ASSOC);
	$blogpost_id = $result["UUID()"];

	// Prepare, bind and execute the insert statement
	$stmt = $conn->prepare("INSERT INTO blogposts (blogpost_id,
		readable_address, title, abstract, content) VALUES
		(:blogpost_id, :address, :title, :abstract, :content);");
	$stmt->bindParam(":blogpost_id", $blogpost_id);
	$stmt->bindParam(":address", $blogpost_addr);
	$stmt->bindParam(":title", $title);
	$stmt->bindParam(":abstract", $abstract);
	$stmt->bindParam(":content", $content);
	$stmt->execute();

	// Add the new tags to the blogpost
	add_tags_to_blogpost($conn, $blogpost_id, $tagStr);

	// Return the newly generated blogposts id.
	return $blogpost_id;
}

/**
 * Update the blogpost content, title, abstract and date edited.
 * Then update the tags.
 * @param $conn				Active Mysql connection.
 * @param $blogpost_id		GUID of the edited blogpost.
 * @param $blogpost_addr	Human-readable address of the edited blogpost.
 * @param $title			Title for the blogpost.
 * @param $tagStr			String with all the tags for the blogpost
 *							(space-separated).
 * @param $abstract			Abstract for the article.
 * @param $content			Content of the article.
 */
function update_blogpost($conn, $blogpost_id, $blogpost_addr, $title,
	$tagStr, $abstract, $content) {
	// Prepare, bind and execute the update statement
	$stmt = $conn->prepare("UPDATE blogposts SET readable_address = :address,
		title = :title, abstract = :abstract, content = :content,
		date_edited = DEFAULT WHERE blogpost_id = :blogpost_id;");
	$stmt->bindParam(":address", $blogpost_addr);
	$stmt->bindParam(":title", $title);
	$stmt->bindParam(":abstract", $abstract);
	$stmt->bindParam(":content", $content);
	$stmt->bindParam(":blogpost_id", $blogpost_id);
	$stmt->execute();

	// Remove old tags from this blogpost
	remove_blogpost_tags($conn, $blogpost_id);

	// Add the new tags to the blogpost
	add_tags_to_blogpost($conn, $blogpost_id, $tagStr);
}

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

display_header("Write article.");

if(isset($_POST["submit"])) {
	// Input will not be sanitized, as it is desirable to allow full control
	// over the content here and only trusted users should have access
	// to this section
	$title = $_POST["blogpost_title"];
	$address = $_POST["blogpost_address"];
	$tagsStr = $_POST["blogpost_tags"];
	$abstract = $_POST["article_abstract"];
	$content = $_POST["article_content"];

	// If adress is empty, set it to null
	if(strcmp($address, "") == 0) {
		$address = null;
	}

	if($_POST["blogpost_id"]) {
		$blogpostId = $_POST["blogpost_id"];
		update_blogpost($conn, $blogpostId, $address, $title, $tagsStr,
			$abstract, $content);
	}
	else {
		$blogpostId = publish_blogpost($conn, $address, $title, $tagsStr,
			$abstract, $content);
	}

	generate_atom_feed($conn);

	// Show button to generate the article
	printf("
<article>
	<form method=\"post\"
	action=\"http://www.zdenekborovec-dev.cz/blog/generatearticle/\">
		<input type=\"hidden\" name=\"blogpost_id\" value=\"%s\">
		<input type=\"hidden\" name=\"referer\"
		value=\"http://www.zdenekborovec-dev.cz/blog/article/%s\">
		<input name=\"submit\" type=\"submit\" value=\"Generate article\">
	</form>
</article>
", $blogpostId, $address);
	include_once($COMMONS."/footer.php");
	die;
}

if(isset($_GET["guid"])) {
	$blogId = sanitize_input($_GET["guid"]);

	// select article title, abstract and content from the database
	$stmt = $conn->prepare("SELECT readable_address, title, abstract, content
		FROM blogposts WHERE blogpost_id = :blogpost_id");
	$stmt->bindParam(":blogpost_id", $blogId);
	$stmt->execute();

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

	// Set prefill values for the form
	$blogId_prefill = $blogId;
	$title_prefill = $result["title"];
	$address_prefill = $result["readable_address"];
	$abstract_prefill = $result["abstract"];
	$content_prefill = sanitize_input($result["content"]);

	// select the tags for this article from the database
	$stmt = $conn->prepare("SELECT blogpost_tags.name FROM
		(blogpost_tags INNER JOIN blogpost_has_tag ON
		blogpost_tags.tag_id = blogpost_has_tag.tag_id) WHERE
		blogpost_id = :blogpost_id;");
	$stmt->bindParam(":blogpost_id", $blogId);
	$stmt->execute();

	$results = $stmt->fetchAll(PDO::FETCH_ASSOC);

	// Construct the string of all blogpost tags to prefill.
	$tagStr_prefill = "";
	foreach($results as $row) {
		$tagStr_prefill .= $row["name"]." ";
	}
}

printf("
<article>
	<form method=\"post\" action=\"\">
		<input type=\"hidden\" name=\"blogpost_id\" value=\"%s\">

		<table class=\"noborder-table\">
			<tr><td style=\"padding: 0px 4px;\">
				<label for=\"blogpost_title\">Post title:</label>
			</td><td style=\"padding: 0px 4px;\">
				<input type=\"text\" name=\"blogpost_title\" value=\"%s\">
			</td><td style=\"padding: 0px 4px;\">
			</td></tr>
			<tr><td style=\"padding: 0px 4px;\">
				<label for=\"blogpost_address\">Address:</label>
			</td><td style=\"padding: 0px 4px;\">
				<input type=\"text\" name=\"blogpost_address\" value=\"%s\">
			</td><td style=\"padding: 0px 4px;\">
				Leave empty to use GUID addressing
			</td></tr>
			<tr><td style=\"padding: 0px 4px;\">
				<label for=\"blogpost_tags\">Post tags:</label>
			</td><td style=\"padding: 0px 4px;\">
				<input type=\"text\" name=\"blogpost_tags\" value=\"%s\">
			</td><td style=\"padding: 0px 4px;\">
				Tags should be separated by spaces, use dash-case, use the
			<a href=\"http://www.zdenekborovec-dev.cz/blog/tageditor\">
				tageditor</a> page to add new tags.
			</td></tr>
		</table>

		<div class=\"centered-container\">
			<textarea name=\"article_abstract\" style=\"width: 100%%;
			height: 5em;\">%s</textarea>
		</div>
		<div class=\"centered-container\">
			<textarea name=\"article_content\" style=\"width: 100%%;
			height: 30em;\">%s</textarea>
		</div>
		<input name=\"submit\" type=\"submit\" value=\"Send File\">
	</form>
</article>
", $blogId_prefill, $title_prefill, $address_prefill, $tagStr_prefill,
	$abstract_prefill, $content_prefill);
	include_once($COMMONS."/footer.php");
?>