Qualche mese fa, @Johani ha rilasciato un eccellente componente per i temi per il lazy loading delle immagini. Ciò significa che le immagini vengono caricate solo quando entrano nella visibilità dello schermo, anziché essere caricate non appena appaiono da qualche parte nella pagina, anche se non sono ancora visibili all’utente.
Questa è un’ottima funzionalità per i forum dove gli argomenti contengono molte immagini, specialmente per gli utenti con connessioni a banda limitata.
Se conosci alcuni dettagli tecnici di Discourse, potresti chiederti: ehi @eviltrout, Discourse non lo fa già in qualche modo? Sì, hai ragione! Effettui uno scrolling infinito e i post vengono caricati e scaricati dalla memoria mentre l’utente scorre. Tuttavia, lo facciamo generalmente in “blocchi”, e su alcune bacheche di immagini un singolo post potrebbe contenere decine di immagini di grandi dimensioni. Perché caricarle tutte insieme se non sono ancora visibili?
Nelle ultime build di Discourse, ora carichiamo in modo lazy le immagini di grandi dimensioni: non sono necessari componenti o plugin aggiuntivi. Se scorri davvero velocemente, vedrai una versione sfocata a bassa risoluzione di un’immagine grande come segnaposto. Assomiglierà a questa:
Dettagli tecnici: generiamo un’immagine molto, molto piccola di 10x10 pixel a 32 colori e la memorizziamo come data URI nel post, che il browser ridimensiona alla dimensione corretta: il risultato è di circa 300 byte.
One thing I’m looking into is applying this to non-lightboxed images, such as those included via oneboxing links.
One issue is it’s a little tricky to know when to apply the logic, since we don’t know the filesize of the destination image. Originally my plan was to append the filesize of images, but it turns out that is quite tricky since we don’t always have a downloaded copy of the image available.
I think I’ll have to come up with a magic width x height, maybe 300x300px or so, and if the image has dimensions larger than that it’ll be lazy loaded. We do have those dimensions available regardless of onebox or upload.
Web bloat I find this article to be a good one on the subject of slow connections, do bear in mind that it has a very minimalistic theme, so don’t judge it by it’s cover so to speak. It might not quite be applicable here, but it’s always good to keep in mind.
I sometimes wish there were ways with Web APIs to detect if someone is on a connection where they pay a lot for bandwidth or one that’s slow.
Yeah I am not sure what the downside will be of going all the way down to 50x50, as long as we do not hit emojis it should be good. Even at 50x50 we may still save 25x if you don’t end up looking at the image
That is completely unrelated. Max allowed image size is controlled in site settings. We already lightbox and thumbnail all images that are posted above a certain size. This is about topics with dozens or hundreds of images in them, not the size of any single image.
Man, I thought I was going crazy. This feature is great for low bandwidth, but now i’m seeing this lazy loading all over the place when I am scrolling our forum. I have so much bandwidth and I’m on a computer. Maybe there should be some sort of buffer around areas you can’t see that load right before you scroll to them? Maybe only for mobile?
Is there anyway that the admin can still play with CSS to modify the lazy loading behavior? The somewhat unintended consequence is that some users are now saying that pictures load on demand more slowly compared to before. I was wondering if its possible to modify the CSS such that instead of either loading all pictures in the next e.g. 20 posts (prior behavior) or pictures only in the current post (current behavior), that we do something in the middle, e.g. load pictures in the next e.g. 3-5 posts.
I’ve been having issues with lazy load more and more lately, I see this at least once a day. It is hard repro, but I’m curious if there is anything I can do to troubleshoot this when it happens? The only thing related in the logs is this:
It is very hard to reproduce, I went into safe mode and had to browse through 30 or so topics before finally hitting one that didn’t work. No related errors in the logs this time. I’m trying to avoid the downtime of testing each plugin, that’s why I’m hoping there may be some hints elsewhere to determine what the culprit may be. Thanks Jeff.
