app/Entities/Tools/ExportFormatter.php
<?php
namespace BookStack\Entities\Tools;
use BookStack\Entities\Models\Book;
use BookStack\Entities\Models\Chapter;
use BookStack\Entities\Models\Page;
use BookStack\Entities\Tools\Markdown\HtmlToMarkdown;
use BookStack\Uploads\ImageService;
use BookStack\Util\CspService;
use BookStack\Util\HtmlDocument;
use DOMElement;
use Exception;
use Throwable;
class ExportFormatter
{
public function __construct(
protected ImageService $imageService,
protected PdfGenerator $pdfGenerator,
protected CspService $cspService
) {
}
/**
* Convert a page to a self-contained HTML file.
* Includes required CSS & image content. Images are base64 encoded into the HTML.
*
* @throws Throwable
*/
public function pageToContainedHtml(Page $page): string
{
$page->html = (new PageContent($page))->render();
$pageHtml = view('exports.page', [
'page' => $page,
'format' => 'html',
'cspContent' => $this->cspService->getCspMetaTagValue(),
'locale' => user()->getLocale(),
])->render();
return $this->containHtml($pageHtml);
}
/**
* Convert a chapter to a self-contained HTML file.
*
* @throws Throwable
*/
public function chapterToContainedHtml(Chapter $chapter): string
{
$pages = $chapter->getVisiblePages();
$pages->each(function ($page) {
$page->html = (new PageContent($page))->render();
});
$html = view('exports.chapter', [
'chapter' => $chapter,
'pages' => $pages,
'format' => 'html',
'cspContent' => $this->cspService->getCspMetaTagValue(),
'locale' => user()->getLocale(),
])->render();
return $this->containHtml($html);
}
/**
* Convert a book to a self-contained HTML file.
*
* @throws Throwable
*/
public function bookToContainedHtml(Book $book): string
{
$bookTree = (new BookContents($book))->getTree(false, true);
$html = view('exports.book', [
'book' => $book,
'bookChildren' => $bookTree,
'format' => 'html',
'cspContent' => $this->cspService->getCspMetaTagValue(),
'locale' => user()->getLocale(),
])->render();
return $this->containHtml($html);
}
/**
* Convert a page to a PDF file.
*
* @throws Throwable
*/
public function pageToPdf(Page $page): string
{
$page->html = (new PageContent($page))->render();
$html = view('exports.page', [
'page' => $page,
'format' => 'pdf',
'engine' => $this->pdfGenerator->getActiveEngine(),
'locale' => user()->getLocale(),
])->render();
return $this->htmlToPdf($html);
}
/**
* Convert a chapter to a PDF file.
*
* @throws Throwable
*/
public function chapterToPdf(Chapter $chapter): string
{
$pages = $chapter->getVisiblePages();
$pages->each(function ($page) {
$page->html = (new PageContent($page))->render();
});
$html = view('exports.chapter', [
'chapter' => $chapter,
'pages' => $pages,
'format' => 'pdf',
'engine' => $this->pdfGenerator->getActiveEngine(),
'locale' => user()->getLocale(),
])->render();
return $this->htmlToPdf($html);
}
/**
* Convert a book to a PDF file.
*
* @throws Throwable
*/
public function bookToPdf(Book $book): string
{
$bookTree = (new BookContents($book))->getTree(false, true);
$html = view('exports.book', [
'book' => $book,
'bookChildren' => $bookTree,
'format' => 'pdf',
'engine' => $this->pdfGenerator->getActiveEngine(),
'locale' => user()->getLocale(),
])->render();
return $this->htmlToPdf($html);
}
/**
* Convert normal web-page HTML to a PDF.
*
* @throws Exception
*/
protected function htmlToPdf(string $html): string
{
$html = $this->containHtml($html);
$doc = new HtmlDocument();
$doc->loadCompleteHtml($html);
$this->replaceIframesWithLinks($doc);
$this->openDetailElements($doc);
$cleanedHtml = $doc->getHtml();
return $this->pdfGenerator->fromHtml($cleanedHtml);
}
/**
* Within the given HTML content, Open any detail blocks.
*/
protected function openDetailElements(HtmlDocument $doc): void
{
$details = $doc->queryXPath('//details');
/** @var DOMElement $detail */
foreach ($details as $detail) {
$detail->setAttribute('open', 'open');
}
}
/**
* Within the given HTML document, replace any iframe elements
* with anchor links within paragraph blocks.
*/
protected function replaceIframesWithLinks(HtmlDocument $doc): void
{
$iframes = $doc->queryXPath('//iframe');
/** @var DOMElement $iframe */
foreach ($iframes as $iframe) {
$link = $iframe->getAttribute('src');
if (str_starts_with($link, '//')) {
$link = 'https:' . $link;
}
$anchor = $doc->createElement('a', $link);
$anchor->setAttribute('href', $link);
$paragraph = $doc->createElement('p');
$paragraph->appendChild($anchor);
$iframe->parentNode->replaceChild($paragraph, $iframe);
}
}
/**
* Bundle of the contents of a html file to be self-contained.
*
* @throws Exception
*/
protected function containHtml(string $htmlContent): string
{
$imageTagsOutput = [];
preg_match_all("/\<img.*?src\=(\'|\")(.*?)(\'|\").*?\>/i", $htmlContent, $imageTagsOutput);
// Replace image src with base64 encoded image strings
if (isset($imageTagsOutput[0]) && count($imageTagsOutput[0]) > 0) {
foreach ($imageTagsOutput[0] as $index => $imgMatch) {
$oldImgTagString = $imgMatch;
$srcString = $imageTagsOutput[2][$index];
$imageEncoded = $this->imageService->imageUrlToBase64($srcString);
if ($imageEncoded === null) {
$imageEncoded = $srcString;
}
$newImgTagString = str_replace($srcString, $imageEncoded, $oldImgTagString);
$htmlContent = str_replace($oldImgTagString, $newImgTagString, $htmlContent);
}
}
$linksOutput = [];
preg_match_all("/\<a.*href\=(\'|\")(.*?)(\'|\").*?\>/i", $htmlContent, $linksOutput);
// Update relative links to be absolute, with instance url
if (isset($linksOutput[0]) && count($linksOutput[0]) > 0) {
foreach ($linksOutput[0] as $index => $linkMatch) {
$oldLinkString = $linkMatch;
$srcString = $linksOutput[2][$index];
if (!str_starts_with(trim($srcString), 'http')) {
$newSrcString = url($srcString);
$newLinkString = str_replace($srcString, $newSrcString, $oldLinkString);
$htmlContent = str_replace($oldLinkString, $newLinkString, $htmlContent);
}
}
}
return $htmlContent;
}
/**
* Converts the page contents into simple plain text.
* This method filters any bad looking content to provide a nice final output.
*/
public function pageToPlainText(Page $page, bool $pageRendered = false, bool $fromParent = false): string
{
$html = $pageRendered ? $page->html : (new PageContent($page))->render();
// Add proceeding spaces before tags so spaces remain between
// text within elements after stripping tags.
$html = str_replace('<', " <", $html);
$text = trim(strip_tags($html));
// Replace multiple spaces with single spaces
$text = preg_replace('/ {2,}/', ' ', $text);
// Reduce multiple horrid whitespace characters.
$text = preg_replace('/(\x0A|\xA0|\x0A|\r|\n){2,}/su', "\n\n", $text);
$text = html_entity_decode($text);
// Add title
$text = $page->name . ($fromParent ? "\n" : "\n\n") . $text;
return $text;
}
/**
* Convert a chapter into a plain text string.
*/
public function chapterToPlainText(Chapter $chapter): string
{
$text = $chapter->name . "\n" . $chapter->description;
$text = trim($text) . "\n\n";
$parts = [];
foreach ($chapter->getVisiblePages() as $page) {
$parts[] = $this->pageToPlainText($page, false, true);
}
return $text . implode("\n\n", $parts);
}
/**
* Convert a book into a plain text string.
*/
public function bookToPlainText(Book $book): string
{
$bookTree = (new BookContents($book))->getTree(false, true);
$text = $book->name . "\n" . $book->description;
$text = rtrim($text) . "\n\n";
$parts = [];
foreach ($bookTree as $bookChild) {
if ($bookChild->isA('chapter')) {
$parts[] = $this->chapterToPlainText($bookChild);
} else {
$parts[] = $this->pageToPlainText($bookChild, true, true);
}
}
return $text . implode("\n\n", $parts);
}
/**
* Convert a page to a Markdown file.
*/
public function pageToMarkdown(Page $page): string
{
if ($page->markdown) {
return '# ' . $page->name . "\n\n" . $page->markdown;
}
return '# ' . $page->name . "\n\n" . (new HtmlToMarkdown($page->html))->convert();
}
/**
* Convert a chapter to a Markdown file.
*/
public function chapterToMarkdown(Chapter $chapter): string
{
$text = '# ' . $chapter->name . "\n\n";
$text .= $chapter->description . "\n\n";
foreach ($chapter->pages as $page) {
$text .= $this->pageToMarkdown($page) . "\n\n";
}
return trim($text);
}
/**
* Convert a book into a plain text string.
*/
public function bookToMarkdown(Book $book): string
{
$bookTree = (new BookContents($book))->getTree(false, true);
$text = '# ' . $book->name . "\n\n";
foreach ($bookTree as $bookChild) {
if ($bookChild instanceof Chapter) {
$text .= $this->chapterToMarkdown($bookChild) . "\n\n";
} else {
$text .= $this->pageToMarkdown($bookChild) . "\n\n";
}
}
return trim($text);
}
}