Bck2BrwsrBlobURLs
From APIDesign
(Difference between revisions)
| Line 6: | Line 6: | ||
public static void onPageLoad() throws Exception { | public static void onPageLoad() throws Exception { | ||
URL u = Main.class.getResource("yourimg.png"); | URL u = Main.class.getResource("yourimg.png"); | ||
| + | // one can use u.openStream() to do 'lightweight' read from Java code | ||
| - | // by opening the connection one requests creation of Blob | + | // by opening the connection one requests creation of browser Blob |
URLConnection conn = u.openConnection(); | URLConnection conn = u.openConnection(); | ||
| - | // the conn.getURL() | + | // the conn.getURL() is actually different URL than u |
| + | // the browser page can really see the URL and use it | ||
changeImg(conn.getURL().toExternalForm()); | changeImg(conn.getURL().toExternalForm()); | ||
} | } | ||
| - | |||
@JavaScriptBody(args = "url", body = "document.getElementById('img').src = url") | @JavaScriptBody(args = "url", body = "document.getElementById('img').src = url") | ||
private static native void changeImg(String url); | private static native void changeImg(String url); | ||
Current revision
For a long time users of Bck2Brwsr complained that loading images, or other resources from the browser's HTML page is complicated. With a great delight I can announce that forthcoming version 0.12 contains a solution. It is build around JavaScript Blob support.
In case you have an application class with an image resource next to it, you can:
public static void onPageLoad() throws Exception { URL u = Main.class.getResource("yourimg.png"); // one can use u.openStream() to do 'lightweight' read from Java code // by opening the connection one requests creation of browser Blob URLConnection conn = u.openConnection(); // the conn.getURL() is actually different URL than u // the browser page can really see the URL and use it changeImg(conn.getURL().toExternalForm()); } @JavaScriptBody(args = "url", body = "document.getElementById('img').src = url") private static native void changeImg(String url);
The conn object in Bck2Brwsr also implements Closeable, so when the URL is no longer needed, it can be freed from browser by (safely) casting and calling close() on it. The full change together with tests is available in Hg history.
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