Examples with LinkElement elemental.html.LinkElement used on opensource projects

Example 1 with LinkElement

use of elemental.html.LinkElement in project flow by vaadin.

the class ResourceLoader method loadHtml.

/**
 * Loads an HTML import and notify a listener when the HTML import is
 * loaded. Calling this method when the HTML import is currently loading or
 * already loaded doesn't cause the HTML import to be loaded again, but the
 * listener will still be notified when appropriate.
 *
 * @param htmlUrl
 *            url of HTML import to load
 * @param resourceLoadListener
 *            listener to notify when the HTML import is loaded
 * @param async
 *            loads the import asynchronously, if {@code true},
 *            synchronously otherwise
 */
public void loadHtml(final String htmlUrl, final ResourceLoadListener resourceLoadListener, boolean async) {
    final String url = WidgetUtil.getAbsoluteUrl(htmlUrl);
    ResourceLoadEvent event = new ResourceLoadEvent(this, url);
    if (loadedResources.has(url)) {
        if (resourceLoadListener != null) {
            resourceLoadListener.onLoad(event);
        }
        return;
    }
    if (addListener(url, resourceLoadListener, loadListeners)) {
        LinkElement linkTag = getDocument().createLinkElement();
        linkTag.setAttribute("rel", "import");
        linkTag.setAttribute("href", url);
        if (async) {
            linkTag.setAttribute("async", "true");
        }
        HtmlLoadListener listener = new HtmlLoadListener(event);
        addOnloadHandler(linkTag, listener, event);
        getHead().appendChild(linkTag);
        if (supportsHtmlWhenReady) {
            addHtmlImportsReadyHandler(listener);
        }
    }
}

Example 2 with LinkElement

use of elemental.html.LinkElement in project flow by vaadin.

the class ResourceLoader method loadStylesheet.

/**
 * Load a stylesheet and notify a listener when the stylesheet is loaded.
 * Calling this method when the stylesheet is currently loading or already
 * loaded doesn't cause the stylesheet to be loaded again, but the listener
 * will still be notified when appropriate.
 *
 * @param stylesheetUrl
 *            the url of the stylesheet to load
 * @param resourceLoadListener
 *            the listener that will get notified when the stylesheet is
 *            loaded
 */
public void loadStylesheet(final String stylesheetUrl, final ResourceLoadListener resourceLoadListener) {
    final String url = WidgetUtil.getAbsoluteUrl(stylesheetUrl);
    final ResourceLoadEvent event = new ResourceLoadEvent(this, url);
    if (loadedResources.has(url)) {
        if (resourceLoadListener != null) {
            resourceLoadListener.onLoad(event);
        }
        return;
    }
    if (addListener(url, resourceLoadListener, loadListeners)) {
        LinkElement linkElement = getDocument().createLinkElement();
        linkElement.setRel("stylesheet");
        linkElement.setType("text/css");
        linkElement.setHref(url);
        if (BrowserInfo.get().isSafariOrIOS()) {
            // Safari doesn't fire any events for link elements
            // See http://www.phpied.com/when-is-a-stylesheet-really-loaded/
            Scheduler.get().scheduleFixedPeriod(new RepeatingCommand() {

                private final Duration duration = new Duration();

                @Override
                public boolean execute() {
                    int styleSheetLength = getStyleSheetLength(url);
                    if (getStyleSheetLength(url) > 0) {
                        fireLoad(event);
                        // Stop repeating
                        return false;
                    } else if (styleSheetLength == 0) {
                        // "Loaded" empty sheet -> most likely 404 error
                        fireError(event);
                        return true;
                    } else if (duration.elapsedMillis() > 60 * 1000) {
                        fireError(event);
                        return false;
                    } else {
                        // Continue repeating
                        return true;
                    }
                }
            }, 10);
        } else {
            addOnloadHandler(linkElement, new StyleSheetLoadListener(url), event);
            if (BrowserInfo.get().isOpera()) {
                // Opera onerror never fired, assume error if no onload in x
                // seconds
                new Timer() {

                    @Override
                    public void run() {
                        if (!loadedResources.has(url)) {
                            fireError(event);
                        }
                    }
                }.schedule(5 * 1000);
            }
        }
        getHead().appendChild(linkElement);
    }
}

Example 3 with LinkElement

use of elemental.html.LinkElement in project flow by vaadin.

the class ResourceLoader method initLoadedResourcesFromDom.

/**
 * Populates the resource loader with the scripts currently added to the
 * page.
 */
private void initLoadedResourcesFromDom() {
    Document document = Browser.getDocument();
    // detect already loaded scripts and stylesheets
    NodeList scripts = document.getElementsByTagName("script");
    for (int i = 0; i < scripts.getLength(); i++) {
        ScriptElement element = (ScriptElement) scripts.item(i);
        String src = element.getSrc();
        if (src != null && src.length() != 0) {
            loadedResources.add(src);
        }
    }
    NodeList links = document.getElementsByTagName("link");
    for (int i = 0; i < links.getLength(); i++) {
        LinkElement linkElement = (LinkElement) links.item(i);
        String rel = linkElement.getRel();
        String href = linkElement.getHref();
        if (("stylesheet".equalsIgnoreCase(rel) || "import".equalsIgnoreCase(rel)) && href != null && href.length() != 0) {
            loadedResources.add(href);
        }
    }
}