I am posting this question because many developers ask more or less the same question in different forms. I will answer this question myself (I am the Founder/CTO of iText Group), so that it can be a "Wiki-answer." If the Stack Overflow "documentation" feature still existed, this would have been a good candidate for a documentation topic.
The source file:
I am trying to convert the following HTML file to PDF:
<html>
<head>
<title>Colossal (movie)</title>
<style>
.poster { width: 120px;float: right; }
.director { font-style: italic; }
.description { font-family: serif; }
.imdb { font-size: 0.8em; }
a { color: red; }
</style>
</head>
<body>
<img src="img/colossal.jpg" class="poster" />
<h1>Colossal (2016)</h1>
<div class="director">Directed by Nacho Vigalondo</div>
<div class="description">Gloria is an out-of-work party girl
forced to leave her life in New York City, and move back home.
When reports surface that a giant creature is destroying Seoul,
she gradually comes to the realization that she is somehow connected
to this phenomenon.
</div>
<div class="imdb">Read more about this movie on
<a href="www.imdb.com/title/tt4680182">IMDB</a>
</div>
</body>
</html>
In a browser, this HTML looks like this:
The problems I encountered:
HTMLWorker doesn't take CSS into account at all
When I used HTMLWorker, I need to create an ImageProvider to avoid an error that informs me that the image can't be found. I also need to create a StyleSheet instance to change some of the styles:
public static class MyImageFactory implements ImageProvider {
public Image getImage(String src, Map<String, String> h,
ChainedProperties cprops, DocListener doc) {
try {
return Image.getInstance(
String.format("resources/html/img/%s",
src.substring(src.lastIndexOf("/") + 1)));
} catch (DocumentException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
public static void main(String[] args) throws IOException, DocumentException {
Document document = new Document();
PdfWriter.getInstance(document, new FileOutputStream("results/htmlworker.pdf"));
document.open();
StyleSheet styles = new StyleSheet();
styles.loadStyle("imdb", "size", "-3");
HTMLWorker htmlWorker = new HTMLWorker(document, null, styles);
HashMap<String,Object> providers = new HashMap<String, Object>();
providers.put(HTMLWorker.IMG_PROVIDER, new MyImageFactory());
htmlWorker.setProviders(providers);
htmlWorker.parse(new FileReader("resources/html/sample.html"));
document.close();
}
The result looks like this:
For some reason, HTMLWorker also shows the content of the <title> tag. I don't know how to avoid this. The CSS in the header isn't parsed at all, I have to define all the styles in my code, using the StyleSheet object.
When I look at my code, I see that plenty of objects and methods I'm using are deprecated:
So I decided to upgrade to using XML Worker.
Images aren't found when using XML Worker
I tried the following code:
public static final String DEST = "results/xmlworker1.pdf";
public static final String HTML = "resources/html/sample.html";
public void createPdf(String file) throws IOException, DocumentException {
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(file));
document.open();
XMLWorkerHelper.getInstance().parseXHtml(writer, document,
new FileInputStream(HTML));
document.close();
}
This resulted in the following PDF:
Instead of Times-Roman, the default font Helvetica is used; this is typical for iText (I should have defined a font explicitly in my HTML). Otherwise, the CSS seems to be respected, but the image is missing, and I didn't get an error message.
With HTMLWorker, an exception was thrown, and I was able to fix the problem by introducing an ImageProvider. Let's see if this works for XML Worker.
Not all CSS styles are supported in XML Worker
I adapted my code like this:
public static final String DEST = "results/xmlworker2.pdf";
public static final String HTML = "resources/html/sample.html";
public static final String IMG_PATH = "resources/html/";
public void createPdf(String file) throws IOException, DocumentException {
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(file));
document.open();
CSSResolver cssResolver =
XMLWorkerHelper.getInstance().getDefaultCssResolver(true);
HtmlPipelineContext htmlContext = new HtmlPipelineContext(null);
htmlContext.setTagFactory(Tags.getHtmlTagProcessorFactory());
htmlContext.setImageProvider(new AbstractImageProvider() {
public String getImageRootPath() {
return IMG_PATH;
}
});
PdfWriterPipeline pdf = new PdfWriterPipeline(document, writer);
HtmlPipeline html = new HtmlPipeline(htmlContext, pdf);
CssResolverPipeline css = new CssResolverPipeline(cssResolver, html);
XMLWorker worker = new XMLWorker(css, true);
XMLParser p = new XMLParser(worker);
p.parse(new FileInputStream(HTML));
document.close();
}
My code is much longer, but now the image is rendered:
The image is larger than when I rendered it using HTMLWorker which tells me that the CSS attribute width for the poster class is taken into account, but the float attribute is ignored. How do I fix this?
The remaining question:
So the question boils down to this: I have a specific HTML file that I try to convert to PDF. I have gone through a lot of work, fixing one problem after the other, but there is one specific problem that I can't solve: how do I make iText respect CSS that defines the position of an element, such as float: right?
Additional question:
When my HTML contains form elements (such as <input>), those form elements are ignored.
