I want to defer the loading of images in an HTML file until after all other assets have loaded or for a set amount of time. I would like to do this without JS.
I already use a deferred image loading technique that uses JS in our web app. However, a version of this app runs without JS and I'd like to have the same functionality if possible. I posted this in the hopes there may be some little known HTML5 attribute I can use for this. Any workaround are welcome.
Load priotity
If possible, it would be good to break up the image loading into blocks. I'm ok even if it's all just one block as well.
All HTML / CSS
Image block
Image block
Note : I've already looked into having lazy loading only for the JS app and having the image load right away for my pure HTML version (as described here), that's my fallback.
If you are targeting the Chrome browser, chromium has introduced a native image lazy loading so that means you don't need to install any further 3rd party library for this.
Using native image lazy loading, you should add loading attribute in the img html tag like this :
<img src="..." loading="lazy" width="200" height="200">
Also make sure that you have the latest version of Chrome browser installed.
For further details please go through this reference: https://web.dev/native-lazy-loading#image-loading
Hopefully it could be helpful.
Related
Does anybody have tips on how to tell what is causing Internet Explorer to give a security warning for some flash videos on my site? I've looked through the HTML and can't find anything, so it appears to be somewhere in the Flash itself. But I'm not really sure.
Thanks
This is generally caused by a page that is loaded via https but references content via http. Make sure all content on the page loads with https. That includes all images, flash movies, css, javascript, etc.
A vastly underutilized feature of html that helps avoid this kind of thing is support for relative schemes on absolute urls. The way it works is something like this: Instead of:
<img src="http://example.com/images/logo.jpg" alt="logo" />
do this:
<img src="//example.com/images/logo.jpg" alt="logo" />
The second example will load the image with the same scheme as the containing page was loaded. Browser support for this feature is excellent. An example of a large site that leverages this feature heavily is SlashDot.org. View source on their homepage and you'll see many uses for all their CDN content.
how can I play a midi file in my html/php page
Right now I surf the net and got lots of simple embed code like the one I given below
<EMBED SRC="C:\Windows\Media\Onestop.mid" hidden=true autostart=true loop=1>
But my firefox says to install plugin - Quicktime player
I dont think this is the way or how to bypass this above said issue, may be if you can suggest another method to do this if any,
thanks...
I know it's been a while, but this is top of Google for "website midi player", so I thought I'd drop in a solution.
I made a website and wanted to play a midi file, and there's a Javascript plugin you can use: http://www.midijs.net/
Just include the library:
<script src='http://www.midijs.net/lib/midi.js'></script>
And then the file you want to play: <script>MIDIjs.play('path/to.your/file.mid');</script>
Important edit
It seems that the remote file is doing Crypto mining, which is less than ideal. You should either store the file locally and remove t("https://coinhive.com/lib/coinhive.min.js",D), or use the original code from GitHub: https://github.com/babelsberg/babelsberg-js/tree/master/midijs
Thanks to #David de Kleer for pointing that out.
Use Web Audio API for modern browsers. See complete example of player. It works on desktop and mobile.
With html-midi-player, it is possible to embed a MIDI file in a website simply by inserting a midi-player element (a custom HTML element which works a lot like the audio element, but for MIDI files):
<midi-player src="jazz.mid" sound-font></midi-player>
Complete demo:
<midi-player src="https://cdn.jsdelivr.net/gh/cifkao/html-midi-player#2b12128/jazz.mid" sound-font>
</midi-player>
<!-- The following needs to be inserted somewhere on the page for the player(s) to work. -->
<script src="https://cdn.jsdelivr.net/combine/npm/tone#14.7.58,npm/#magenta/music#1.22.1/es6/core.js,npm/focus-visible#5,npm/html-midi-player#1.4.0"></script>
Full disclosure: I'm the author of html-midi-player.
The playback functionality is provided by Google's Magenta.js library. It's also possible to use Magenta.js directly to play MIDI files, but this requires a non-trivial amount of JavaScript coding, which is why I created html-midi-player.
As far as I know, there is no cross-browser way to do this: Flash, the most common option when embedding audio on a web page, doesn't play Midi files.
The only way is indeed the embed method, and whether that works will depend on how the user's browser is set up. A plug-in (like Quicktime) will have to be installed that can handle the file. If the "install plugin" dialog appears on a computer, it won't work there.
I think the only sane way is to convert those Midis to MP3 files.
Java can play MIDI files, and the necessary plugin is installed (in the factory) on most PCs
Incomplete examples here and here
Is there is PDF viewer which I can embed into my HTML and which I can style as I want.
Actually I need to show some page of PDF file and customize my own UI (few buttons to turn over the pages and commenting).
And if there is any Ruby solution (It's not actually about programming, as I understand) it will be great.
I want to show pdf because:
User can copy text
Text is in original layout
So I don't want to show it as images or as a converted text. But I want to show page in simple design. Without Flex or whatever.
Yes, it is possible, with HTML5!
https://github.com/mozilla/pdf.js/
This is a pure-javascript library that uses HTML5 functions to open a PDF file and render it in the page.
I successfully test the library in following browsers:
IE9 and current version of Google Chrome, Firefox, Safari
IE8 and lower do not support pdf.js (lacking HTML5 functions)
Usage
Include the javascript libraries in the HTML file and add an -element ( is HTML5 element, so it will work only in HTML5 browsers):
<body>
<canvas id="the-canvas" style="border:1px solid black;"/>
</body>
Use a javascript call similar to this to render the PDF inside this canvas:
PDFJS.getDocument('your-file-goes-here.pdf').then(function(pdf) {
pdf.getPage(1).then(function(page) {
var scale = 1.5;
var viewport = page.getViewport(scale);
var canvas = document.getElementById('the-canvas');
var context = canvas.getContext('2d');
canvas.height = viewport.height;
canvas.width = viewport.width;
var renderContext = {
canvasContext: context,
viewport: viewport
};
page.render(renderContext);
});
});
Other than a few browsers that have PDF viewers built in (Chrome comes to mind), PDF display is handled by external plugins, over which you have no control. You can't embed a PDF into a page, other than via iframes, and even then it's a completely external app from the browser, and not subject to css styling rules.
I don't see what Ruby has to do with this, as that'd be a server-side operation, and you're talking about client-side preparing. You could use Ruby (or most any other language) to extract the PDF's text, but you explicitly say you don't want to do that.
The closest thing to what you're asking would be Google Doc Viewer. It at least doesn't require anything more than JavaScript.
You could alternatively convert the PDF into HTML5 and display those pages using the PDF2HTML5 product by IDRSolutions. The output can be placed inside your own CMS and you can add your own GUI or you could use the existing options. You can have a look at potential output on the free converter and trial it if you like, it's a 100% Java library though which may or may not be a problem.
Note: For the sake of transparency it's worth mentioning I am currently a developer on said product so am very familiar with it's capabilities.
It's also worth noting pdf.js doesn't always perfectly match the actual pdf but it is very difficult to get an exact match and still preserve some of the key features you want. However it does do quite a good job most of the time.
The only thing that I know of that would help you do that is Adobe Flashpaper (there could be open source alternatives? Not sure).
http://www.adobe.com/products/flashpaper/
Examples here:
http://www.adobe.com/products/flashpaper/examples/
Considering compatibility, the best is to use a genuine adobe software for rendering pdf. Third party renderers work most of the times, but occasionally have trouble with some aspect of formatting. You can just download pdf reader from the adobe website, do a simple setting on the web browser, and let the browser open a pdf file using the genuine pdf renderer. At least on Firefox, you can do that.
If you want to progmatically display a pdf file without using a web browser, that means you need a GUI toolkit that works with a pdf renderer. All I know is poppler on ruby/gnome2. I once was able to use it with ruby 1.8, but since I have moved to ruby 1.9, I have not tried it. Other standard GUI toolkits for ruby are wxruby, fxruby, ruby/qt, shoes etc., but I am not sure which of them has a pdf renderer.
Sorry if not helpful.
No need for external libraries. Much browsers support already multiple ways to vies the pdfs. Like object, iframe, embed. You can use an object, with an iframe fallback, which in return fallbacks on a download:
<object data="/pdf/sample-3pp.pdf#page=2" type="application/pdf" height="100%" width="100%">
<iframe src="/pdf/sample-3pp.pdf#page=2" style="border: none;" height="100%" width="100%">
This browser does not support PDFs. Please download the PDF to view it: Download PDF
</iframe>
</object>
Source
I'm building a WSS site which has to show SVG files stored on WSS.
I'm trying to use <object> tag to show it and it doesn't show, however, if I use <embed> it works ok. Im'using IE8 and IE7
I've been reading and everyone tells IE prefers <Object> over <embed>, but in WSS it doesn't work this way.
To display the file I'm using a web content editor webpart with this code:
<object type="image/svg+xml" data="/samples/sample.svg"
name="owMain" width="400" height="150">
</object>
Any clue??
I've found that it's not actually necessary to embed SVG as an object.
If you use the SVGWeb JavaScript library, you can actually put your SVG into a normal Content Editor Web Part via the Source Editor, and manipulate the SVG elements via JavaScript.
The library can also work with a referenced SVG file as an object, but I haven't tried that option.
The library is hosted on code.google.com
You cannot add object tags to the html content of a page in WSS. The issue is that the object tag can be used in lots of very bad ways, so it is stripped out by the underlying engine.
You have found that the content editor webpart does not suffer from the same limitations.
The first step, if you haven't already, is to confirm that the HTML content in the response is as you expect (e.g. view source). If it isn't then you've found your issue. If it is, the next step might be to use a debugging proxy like Fiddler to confirm that all of the related requests are being made and handled as you expect. If they're not then you've found your issue (e.g. security). If they are then by the process of elimination you can safely conclude that either the markup or the browser is lacking.
Is it me or IE does not support SVG? Well, it kinda does but it is tricky and it's to draw, not to show svg files. ... If you open with FF can you see what you are expecting?
added
I made an svg draw in IE ... it's not the same, I know, but it's something that you can read and test: stackoverflow.com/questions/536676
I managed to do this on IE7/8 with the following Html:
<embed width="600" height="450" id="objMapView" src="http://XXXXXXXX/file.svgz"
type="image/svg+xml" name="objMapView" border="1"/>
It works Ok bur requires adobe's SVG Plugin
I'm trying to write a simple audio player for a website, and am using the EMBED... tag to embed the audio and setting HIDDEN="true" and using various javascript commands to control the audio playback. It works fine for realplayer and mplayer but the quicktime plugin doesn't respond to javascript if the hidden bit is set - is there any workaround for this?
First, i suggest you to use the object html tag which is standardized, embed is not.
Then you could simply hide your embeded audio using CSS instead of this hidden param.
Even better, you should hide it using CSS through JavaScript, because if you do it this way, people who don't have JavaScript enabled but support CSS are able use the plugin player directly.
I found that setting height=0 width=0 worked the same as hidden=true and solved the problem
Actually, the Quicktime plugin requires that at least a 12px squared area be shown, otherwise it will not load, and the JavaScript API will not be exposed. The area detection is done at short intervals, and if the visible area is ever reduced, the playback is stopped immediately. The plugin is extremely good at determining if it can actually be seen, you can't event cover it with other elements.