I have just noticed that my rails app is now stripping out all seemingly unnecessary white space from my fields. It never used to do this, and I have (perhaps foolishly) some javascript that is relying on this white space which is now not working.
How can I turn this off?
I've never seen Rails doing this. Perhaps your server is trying to minimize html and stripping out unnecessary whitespaces?
Related
I'm optimizing the speed of a WordPress website (on mobile only for the moment), with success except for CLS. The CLS became extremely high after optimizing CSS delivery (with WP-Rocket), but I don't see any layout shifts, even when I use Dev Tools (performance test). (on mobile)
Here’s the example : https://trustmyscience.com/israel-a-pratiquement-eradique-la-covid-19/
Results here, with CSS delivery optimization
So it seems to be an invisible layout shift, that Lighthouse perceive as a real layout shift. Lighthouse shows me the problem comes from <div class="entry-content body-color clearfix link-color-wrap progresson">. So, it seems to be related to some "wrapping" of the all article content, that maybe shifts into the background (without being visible), because of some CSS rules maybe ?
Here, the element with the highest layout shift
The element with the highest layout shift (detail)
When I deactivate CSS delivery optimization, CLS go back to almost 0 (but LCP is too high).
Results WITHOUT CSS delivery optimization
I need this CSS delivery optimisation because of LCP importance, but I also now need to solve this issue because of CLS introduction in Core Web Vitals, and need to find what Lighthouse is detecting as a LS. Also, maybe, Lighthouse needs a correction for that ? As it isn't a visible layout shift...
Do you have any idea on how to solve this ? Or do you think I need to reach LS developers to show them this ?
Thank you in advance for your help.
Regards,
The CLS is visible, it's the font.
Don't you notice that when you visit the page, the text gets resized? That's a common cause of CLS.
How to solve?
Serve your fonts locally. Do not use any plug-in like OMGF. Do it manually.
Download the fonts. Choose 2 fonts, one for body, another for headings. You won't need bold, italic, or bold+italic fonts. These will be applied by user's browser.
Convert to woff2 (only woff2 is enough, didn't face any issues)
Upload it to your server
Add font face CSS to declare the fonts
Apply the fonts using CSS elements
Disable Google fonts if you're using any WP theme or builder
Preload the fonts
This will solve the CLS problem, will also reduce the Total Blocking Time.
You might gain a bit in performance by self-hosting the fonts instead of making a call to the Google Fonts API, but fonts are not the main issue here. Javascript is.
There is a lot of Javascript on this website, so the main thread is busy downloading it, parsing it and executing it.
I ran both Lighthouse (with Clear Storage and Simulated throttling enabled) and WebPageTest with a Moto 4G profile.
As you can see from Chrome DevTools and WebPageTest, roughly 56% of the processing time spent on the main thread is due to scripting. Do you really need all of that Javascript?
Here is what I noticed in the Chrome DevTools Performance panel:
There seems to be 5 front-end.js scripts (and 1 min-front.js). Are they duplicates?
Do you need animations with gsap and ScrollTrigger?
Aren't lazyload.min.js and areimagesloaded.js doing the same thing? (I might be wrong)
Are you importing the entire lodash library? If so, try importing just the functions you are actually using.
Do you really need a polyfill for Intersection Observer? I think that all modern browsers support it natively nowadays.
CLS is basically the sum of all unexpected layout shifts that occur on a page. As you can see from the dashed orange line in the chart below, the 4 .woff2 font files contribute to the CLS: the first layout shift occurs as soon as the fonts are fetched.
But as I said, I would focus on removing all unnecessary Javascript. In particular, I would examine third-party JS like the one coming from choices.consentframework.com, which takes 1730ms to load and represents 25% of the content size (see below).
After JavaScript, focus on the images.
The Performance panel in Chrome DevTools shows a lot of requests for images. Are you fetching only the images that are in the viewport, or all the images that are on the page?
Most of these images are WebP and seem already optimized, but there are a few GIFs, which are really bad for performance. It seems that these GIFs are served by https://www.viously.com/ (I guess it's an Ad Server, it's the first time I see it).
Last but not least, double-check that all of your <img> and <video> have size and width attributes set. Images and videos are replaced elements with intrinsic dimensions, and forgetting to set sizes for images in your HTML is a common cause of layout shifts.
See also this article by Addy Osmani for a few more tips on how to optimize CLS.
My app uses a custom font (by Linotype, i.e. a professional font). In UILabels as well as UITextViews and TextFields, composite glyphs like the German ö, ä and ü are rendered in incorrect size and weight.
I tried quite a lot from changing trying other fonts (which rendered as expected) to testing other font sizes, but always had this artifact.
Does anybody have a clue, what the problem with that font could be?
As a sidenote, the android app renders that same font just fine, which only hints that font rendering engines on the two platforms are likely different.
Here is an example (check the the ü-glyph):
I spent a lot of time trying to figure out the cause, but ignored the obvious: the string literal in the strings resource file was copied from another application (or a pdf I guess) and contained the composed characters in a kind of alternative way.
After retyping the text, which which contained odd characters, they were rendered perfectly fine!
I know it looks like I only wrote the question to answer it myself, but it is just a happy incident that I found the cause just now while going on examining the problem.
When printing our website's page from ie9, certain characters are consistently distorting themselves like so (should say "301 results"):
Capital B's, S's, and 8's are also uniformly distorted. I've found fixes for garbled and nonsense text, but fixing this sort of distortion is eluding me. Also, everything prints perfectly from Chrome, so it's not an issue with the printer.
We're using Angular on a Ruby on Rails base, if that matters.
I am working on an app that needs to change a lot of CATextLayers strings, but, only one or two characters of it(in general though, the strings are in length of about 2-5 characters).
At first I went with UILabels which were extremely slow, and because of that I tried out CATextLayer, which was a lot faster, but not fast enough, I am updating about 150 CATextLayers quite often, all at once , and it just doesn't cut it, I feel a lag.
I then tried out to do it even more low-level with CoreText, I tried drawing it with a CTLine, which had about the same performance of CATextLayer, so I got back to the CATextLayers because my positioning code for CoreText wasn't perfect.
I started thinking about caching for each string the first two characters(which are always constant), and only changing the other 3 characters, with smaller bounds, which I assume will be a bit faster, but, will it be faster? After all it will have it to composite it with the other text-layer, and it will have to be update all of the 150 text-layers.
Does anybody have any advice? How would you approach it?
Attached is a screenshot from instruments showing that the problem lies in the performance of CATextLayer:
Bitmap Fonts are probably the best way to solve this problem, as they're far and away more performant than anything else in terms of font drawing for something of this nature. But you need to pre-render them to the scale you desire to get the best out of them both visually and in terms of performance.
And you might be best off using Sprite Kit, as it has native handling of them. Here's a github repo with a useful thing to make it easier to use rendered bitmaps from a common tool for creating them: https://github.com/tapouillo/BMGlyphLabel
In CSS Sprites you will often find padding between each image. I believe the idea is so that if the page is resized then one image won't bleed into another.
I think this depends on the different types of browser zoom (best explained by Jeff).
However, I haven't been able to see this behaviour in my tests. Is this only a problem with older browsers? (I havent been able to test with IE6 at the current time so I'm counting that as 'old').
Should I still worry about leaving space? Its kind of a pain.
For instance :
A CSS Sprite I found for AOL has
padding between each image : VIEW
but The Daily Show decided not to
bother : VIEW
It shouldn't need to be padded, but when zoomed, especially in IE8 (betas more than the RC), there is image bleeding if there is no padding.
Best example is to go to Google.com -> Search, and zoom... you'll start to see "underlines" at the bottom right of the image as the zooming rounds up/down.
In theory, a 1px padding on all sides of a sprite should be fine.
Here's the sprite from Google (images)...
But when zoomed, the +,-,x icons bleed into the main Google logo.
Basically the answer is yes. Two years to the day after I asked this question will see the release of IE9. IE9 has this problem just as much - if not more than any other browser...
It's pretty infuriating because it's such a simple thing to fix.
With iPads increasing in marketshare - its's pretty essential to at least have a half decent experience with zooming un-uniform amounts.
I am going to have to put a single pixel border around every image to match the background color of the adjacent element (potentially different on each side). Fortunately I auto-generate all my csssprites based on an .xml file - so I can do this programatically without too much hastle. It's still a huge pain though...
Simon - My experience is that this is certainly still a problem.
In response to your second question, why not use transparent padding? (Perhaps you are still supporting ie6 and this is non-trivial, in which case, I'm really sorry).
Speaking of the older browsers (those using text zoom), you don't always need padding.
The main difference between your two examples is that the Daily Show sprite already includes the menu item's text in the image itself.
When using text zoom, the AOL menu items could stretch out vertically due to the larger font size, and the menu text might even wrap to two lines. To accommodate for such eventualities, those icons need a little padding to ensure they don't bleed. Typically, you'd just try to make sure it doesn't bleed on any of IE6's five text sizes.
Since The Daily Show's menu doesn't contain any (visible) HTML text its size won't be affected by text zoom (though you might need a line-height: 0; or so to be sure), so it doesn't need any padding.
As scunliffe already showed, browsers using page zoom may need sprites to have a little padding due to rounding errors.