/**
* {@inheritDoc}
*
* @see
* ch.entwine.weblounge.common.content.PreviewGenerator#createPreview(ch.entwine.weblounge.common.content.Resource,
* ch.entwine.weblounge.common.site.Environment,
* ch.entwine.weblounge.common.language.Language,
* ch.entwine.weblounge.common.content.image.ImageStyle, String, java.io.InputStream,
* java.io.OutputStream)
*/
public void createPreview(
Resource<?> resource,
Environment environment,
Language language,
ImageStyle style,
String format,
InputStream is,
OutputStream os)
throws IOException {
// We don't need the input stream
IOUtils.closeQuietly(is);
// Find a suitable image preview generator for scaling
ImagePreviewGenerator imagePreviewGenerator = null;
synchronized (previewGenerators) {
for (ImagePreviewGenerator generator : previewGenerators) {
if (generator.supports(format)) {
imagePreviewGenerator = generator;
break;
}
}
if (imagePreviewGenerator == null) {
logger.debug("Unable to generate page previews since no image renderer is available");
return;
}
}
// Find the relevant metadata to start the request
ResourceURI uri = resource.getURI();
long version = resource.getVersion();
Site site = uri.getSite();
// Create the url
URL pageURL =
new URL(
UrlUtils.concat(
site.getHostname(environment).toExternalForm(),
PAGE_HANDLER_PREFIX,
uri.getIdentifier()));
if (version == Resource.WORK) {
pageURL =
new URL(
UrlUtils.concat(
pageURL.toExternalForm(), "work_" + language.getIdentifier() + ".html"));
} else {
pageURL =
new URL(
UrlUtils.concat(
pageURL.toExternalForm(), "index_" + language.getIdentifier() + ".html"));
}
// Create a temporary file
final File rendererdFile = File.createTempFile("phantomjs-", "." + format, phantomTmpDir);
final URL finalPageURL = pageURL;
final AtomicBoolean success = new AtomicBoolean();
// Call PhantomJS to render the page
try {
final PhantomJsProcessExecutor phantomjs =
new PhantomJsProcessExecutor(
scriptFile.getAbsolutePath(),
pageURL.toExternalForm(),
rendererdFile.getAbsolutePath()) {
@Override
protected void onProcessFinished(int exitCode) throws IOException {
super.onProcessFinished(exitCode);
switch (exitCode) {
case 0:
if (rendererdFile.length() > 0) {
success.set(true);
logger.debug(
"Page preview of {} created at {}",
finalPageURL,
rendererdFile.getAbsolutePath());
} else {
logger.warn("Error creating page preview of {}", finalPageURL);
success.set(false);
FileUtils.deleteQuietly(rendererdFile);
}
break;
default:
success.set(false);
logger.warn("Error creating page preview of {}", finalPageURL);
FileUtils.deleteQuietly(rendererdFile);
}
}
};
// Finally have PhantomJS create the preview
logger.debug("Creating preview of {}", finalPageURL);
phantomjs.execute();
} catch (ProcessExcecutorException e) {
logger.warn("Error creating page preview of {}: {}", pageURL, e.getMessage());
throw new IOException(e);
} finally {
// If page preview rendering failed, there is no point in scaling the
// images
if (!success.get()) {
logger.debug("Skipping scaling of failed preview rendering {}", pageURL);
FileUtils.deleteQuietly(rendererdFile);
return;
}
}
FileInputStream imageIs = null;
// Scale the image to the correct size
try {
imageIs = new FileInputStream(rendererdFile);
imagePreviewGenerator.createPreview(
resource, environment, language, style, PREVIEW_FORMAT, imageIs, os);
} catch (IOException e) {
logger.error("Error reading original page preview from " + rendererdFile, e);
throw e;
} catch (Throwable t) {
logger.warn("Error scaling page preview at " + uri + ": " + t.getMessage(), t);
throw new IOException(t);
} finally {
IOUtils.closeQuietly(imageIs);
FileUtils.deleteQuietly(rendererdFile);
}
}
/**
* {@inheritDoc}
*
* @see ch.entwine.weblounge.common.content.PreviewGenerator#supports(java.lang.String)
*/
public boolean supports(String format) {
for (ImagePreviewGenerator generator : previewGenerators) {
if (generator.supports(PREVIEW_FORMAT) && generator.supports(format)) return true;
}
return false;
}