I'm attempting to perform some styling to handle page breaks when printing, to ensure my content does not get cut in half.
I know the styles requried to perform this (page-break-inside etc) but attempting to verify they work is a rather laborious task, especially when i can't query the DOM whilst its showing me the preview.
In Chrome (or any other browser for that matter) is it possible to put the page into print mode and have it render where the page breaks will be placed?
Currently i can use Dev tools to enable the print media queries, but the only way to see where the page breaks will take place is to actually bring up the print preview. However when thats up i can't interact with the DOM to see why elements do or don't get cut in half by the break.
When it all works this isn't really an issue but as we all know things tend to behave oddly more often than not!
Thanks
Related
I have a single page using CSS columns that reflows on load.
Even when I remove all IMGs and iFrames, so it is fetching no
external resources, it reflows.
I can't figure out what is causing the reflow/repaint. Any CSS exports
out there able to figure this one out?
https://github.com/treenotation/dumbdown/issues/8
There's too much content in document.
The browser will gradually display the content, that is, the content involved in rendering will gradually increase, which affects the layout calculation.
You can add the "loading state" style. When window.onload Event trigger, change the style to "load complete".
Or 'Masonry Layout'.
Reason for the reflow is: a huge amount of content but NO strategy to handle with. Indeed there are many things you can avoid/do/change ...
REASON WHY - just to base the answer ...
The reflow is caused by the mechanic: at first the text (html code) has been downloaded and rendered. But there are still a lot of elements (most over images but youtube videos and iframes as well) which are still on download. As the browser don't know the size of that elements he does not keep the place for that elements.
Now: after the download and rendering of every element has finished the browser injects the element to the content and all off the following content is pushed down and in your case to next column ... reflow.
STRATEGY: MULTIPLE ACTIONS
To your question: there is not only one reason which causes multiple and long downloads. So far there is no simple single answer and even NOT A SINGLE SOLUTION. Your needed strategy will be to optimize the page by a multiple bundle of actions. But I believe doing that you can reduce it to an acceptable amount ... and maybe there is a chance.
THINGS YOU CAN DO
1. Change layout
If you change the layout to an actual web technique. That means don't use columns (flowing left to right) to a style which prepares the pageflow from up to down. Than you can asynchron load the needed elements when the user scrolls down. The technique is named Infinite scrolling: How to do an infinite scroll in plain Javascript
But I assume as the special layout has charm this won't be an option for you!?
2. Images which are not shown - remove not needed elements from download
On your page I found images which are downloaded but which are not shown on the page. (Example: 3.png with INCREDIBILE USELESS 659KB). Remove such elements from your content.
3. Reduce not needed size of elements
Additional a lot of shown images on your page have an incredibly large file size which is not needed.
Example: devices.png
image-size: 692x285px - real size
layout-size: 287x118px - needed size
file-size-download: 110kb
file-size-needed: 4kb - if (lossless) optimized
And think about: many little file downloads add up to a big amount ... and you have a lot of downloads! If you calculate: 10 images your way: 1.1 MB can be done with 40KBs
Additional:
if you you need higher solutions use srcset attributes ...
sometimes that is a practical problem with the knowledge of the editors: than teach them how to lossless reduce images and advise them the sizes to use for the images in the layout
4. Use faster server for images
It seems the download rate from your server is not the fastest one. That's normal by most providers. As you have a lot of images ... think about to load images from a faster server - if possible. Example: the pure download service from AWS (Amazon Web Service) is incredibly fast. As you just need a bucket for downloading that is not as expensive ... try it out.
5. Use placeholders for elements
As you have a lot of elements I think you maybe cannot avoid the later injection which causes the reflow. But you can use placeholders for your element so the needed place is reserved and the reflow still does not happen for this element.
Just define the html structure and possible sizes in your layout. That additional helps the editors as they know what image size they can use. Then size the placeholders with CSS and initiate an ajax image download by JS.
In case of later download now the users maybe see a placeholder at the beginning but no reflow. You can do that with few lines of code. I attach an example at the end of the posting.
NOTE: You can do this with (youtube-)videos or iframes in a similar way ;-)
6. Use vanilla instead of jQuery
As I saw has the download of jQuery an incredible impact to your download time. Really. (That's the reason why I assume your server is a slower one.) Have a look to the download time of your elements. It is one of the elements which needs the most times and blocks your elements from rendering.
jQuery is an old dog. Modern web techniques use vanilla JS ... and as I see there are no complicated things on your page you cannot realize in vanilla. So the recommendation is to remove it from you page (if possible) and you will earn a huge speed advantage.
7. Use CDNs for download when possible
Downloading frameworks and fonts from own server makes pages slow and blocks time for the page download of other elements. Use a CDN instead.
As I have seen your fonts are loaded from a CDN? But jQuery still comes from your server. If you don't want to change to vanilla chose to load it from CDN.
8. Check if Youtube can be loaded more simple
Youtube is loaded by several actions to your page. In this case I AM NOT SURE as I still did not work with youtube for a longer time. But I believe (not sure if I am right) that there is a more direct way to include youtube videos to a page. Maybe you would like to check it.
But nevertheless: work with placeholders for the video players as well. That are almost just few additional lines off css.
9. Optimizing user experience: thinking about a preloader
Reflow is not new phenomenon to webpages. Up to now a lot of pages uses preloaders to generate a better user experience. Today's technique is ajax load...
I don't know if the described techniques will avoid the reflow completely. As there are many elements the download time cannot be set to zero. But optimizing the page will reduce it dramatically. If there still remains a little bit ... maybe you like to think about the older technique. Using a nice and maybe well designed preloader symbol indeed can upgrade the user experience. Maybe on mobile views with medium data speed there is no other chance...?
But that is just to think about an additional possibility ...
[update]
10. Combine placeholder with infinite scroll
If you are using placeholders you can/should combine it with technique infinite scroll.
Means: all media (particularly images but maybe videos and iframes as well) are prepositioned by sized placeholders. That works immediately so there should be no more reflow as needed. Then load media assynchron by AJAX based on their position on their screen. Images which are in view are loaded immediately.
As you don't have so many media elements on starting viewport (most are still below the screen view) that should work as if it is a page with a 'normal number' of pictures/medias.
All others are loading afterwards when scrolling the page the media comes in view like on a 'infinite scroll page'. (Note: that works if the file size off the images is not to large, - so optimizing the images has still to be done.)
That has the additional advantage that thake makes sure that the images are loaded in the sequence they are needed ... which safes a lot of time.
Could be done in javascript:
Place images/media by placeholder technique
On window.onload check which images/media are in the viewport. Don't forget images which are only partly seen.
On window.onscroll check if image(s) comes to viewport and load image
Note: I am not quite sure if there are anchor links on your page to the single articles. I believe not. But if you still use them the starting viewport can be anywhere on the page when the user call an article. In that case window.onscroll has not only to work scrolling down but scrolling up to.
I am not quite sure if there is a ready script avaiable. But I would wonder if not. Otherwise it would not be to tricky to do that on your own. That would have the charm that such scripts mostly have less and cleaner code than preworked scripts ...
[end update]
... ... ...
I am not quite sure if the described issues are complete. Mostly there are found more possibilities to optimize a page when you start with the process. But as I had a nearer look to your page that are the most important chances.
EXAMPLE LAZY IMAGE LOAD WITH PLACEHOLDER EFFECT
Just EASY AND SIMPLIFIED example for lazy image load. Please adapt to your need.
// new html for image
<img class="placeholder-size" src="path/placeholder.jpg" data-lazy-url="https://url-to-your/imag.png" alt="Image Description">
// css
.placeholder-size {
width: 200px;
height: 100px;
}
// js for lazy load
// older code but works, please actualize if needed
window.onload = function(){
var lazyImages = document.querySelectorAll('[data-lazy-url]');
for (var i in lazyImages) if (lazyImages.hasOwnProperty(i)) {
var imgUrl = lazyImages[i].getAttribute('data-lazy-url');
lazyImages[i].src=imgUrl;
};
};
I have created a print button in my application that opens a new window that goes to print device layout by appending the current url with QueryString of Print device(?p=1 in my case) and onload it calls window.print() function. But this is useless because all the data user has entered will be lost when it opens a new window containing print device layout of the current page.
I can't think of a way by which I can use the print device layout and pre-populate the page with data user has entered. Can anyone help me with this?
Thanks in advance.
The point of the Print Device to be able to have a different set of Presentation components for display or print. Sometimes it is sufficient (and easier) to just use a print stylesheet, which hides/restyles certain elements: https://stackoverflow.com/a/12773239/19112
Obviously Devices works fine for non-form pages, or forms that have been posted and a confirmation page is shown (no input boxes, just text).
An alternative would be to use Rendering Parameters to set on each control, which could add a .print or .do-not-print class to then be used by the print stylesheet. You would then have to set the appropriate styles in the stylesheet to hide those elements. Note however that you cannot style the iframe content from the parent, you must link a separate stylesheet to the iframe src page if you want to style when printing.
You can append the user inputs to the print URL query string using javascript, for example:
var url = 'Current-Page-URL' + '?p=1' + '&input1=[INPUT1]'+ '&input2=[INPUT2]' etc..
Then in Page load event, you can set these inputs in the corresponding text/dropdown elements
Like mentioned above that device is a different set of presentation that can be used for many purpose. Early years when there weren’t responsive design, I used device to rendering different mobile device. You can use device to render rss feed or anything you want where you want to have different render set.
Another example if you have multi sites and want to rendering them differently you can use device as well.
Sitecore is very flexible that’s why I love it so much. There are always other ways to get same or similar results. From your context I don’t know what you are trying to achieve. If I want to have different set of presentation
here is some approach I will look into, Lavage rendering rules, tap into request pipeline, swap rendering controls in code, on item level specify style sheet…
If you can tell us what you are trying to achieve, I am sure someone will provide you their own solution. Then you will have more options to choose from and get the best fit to your project.
Hope this help.
Currently, I'm investigating several tips/recommendations for improving the performance of web sites. So, I've started with Steve Souders' excellent books (High performance web sites and even faster web sites), but I've got a couple of questions regarding some of the rules that are presented. FOr instance, chapter 5 of High performance web sites say that CSS stylesheets should be put at the top of the page because putting them at the bottom stops the progressive rendering that is performed by the browsers. According to Steve, some browsers (most notably IE) do get stuck with it and show a blank page instead of showing the items progressively. Here's the url for that test page:
http://stevesouders.com/hpws/css-bottom.php
Now, I do understand that we're talking about a book with a couple of years and that browsers (including IE) have been updated and improved. The reason I'm asking this is because I can't reproduce the behavior he mentions with any current version of FF, Chrome or IE.
Well, the thing is that Yahoo (http://developer.yahoo.com/performance/rules.html#css_top) and google (https://developers.google.com/speed/docs/best-practices/rendering#PutCSSInHead) still say that.
So, what I'd like to know is if browsers have evolved in this area and this is only problematic for, say IE 8? If that is the case, why haven't yahoo and google updated their recommendations? (btw, I've tried simulating IE7 from within IE11 and still don't see the expected result that is described in the book...)
*UDPATE*One more final note: I've decided to reproduce Steve's cgi script in asp.net and I've created a simple generic handler that does the same thing as the sleep.cgi script. what I'm seeing here is that putting a stylesheet reference (which takes some time to load - I've went with 10 seconds) inside the head ends up producing the blank page problem that is reported in the book. If you put at the end, the browser ends up rendering everything and making a second pass for applying the styles after they have been loaded. In my opinion, this makes sense because when you put the style in the header element, the browser is holding up until it gets the styles before rendering (notice that the other referenced components are still being downloaded on the background, but they're not being shown in the screen). On the other hand, when they're at the bottom, the browser will simply apply the current styles until it gets stuck in the stylesheet. WHen that happens, it will only show the html it has loaded until the stylesheet (if there are any images below it, the browser will still download them but it will only render them after the styles have been loaded).
So, after these tests, I'm starting to think that 1.) I'm missing something here or 2.) yahoo and google recommendations are no longer valid today.
Thoughts?
Thanks guys!
Simply inserting a <link> tag in the footer is not the way to defer stylesheets. The currently accepted method is to attach it using javascript:
<script>
function loadStyleSheet(e){if(document.createStyleSheet)try{document.createStyleSheet(e)}catch(t){}else{var l;l=document.createElement("link"),l.rel="stylesheet",l.type="text/css",l.media="all",l.href=e,document.getElementsByTagName("head")[0].appendChild(l)}}loadStyleSheet("/your/stylesheet.css");
</script>
Optimizing your page for speed involves determining what CSS is above the fold, inlining that part in the header, and loading the main stylesheet later using the above method.
I recommend doing some searches for "above the fold css" and check out Google Pagespeed Insights.
https://developers.google.com/speed/pagespeed/insights/
This may sound like a SuperUser issue, but I wrote the page in question and I'm wondering if there is something I can do to fix the problem....
I have a page in production that simlply displays data in a bunch of tables. Our employees basically go to this page to print a form with our clients information filled in for them. Today for a specific client the page is not printing. I've tried printing using IE 7 and 8 as well as Chrome on Windows XP and Windows 7. This client's data is by no means make the page longer or contain more data that others clients.
Symptoms:
Does NOT print using IE8 or IE7 on WinXP and Windows 7.
DOES print with Chrome.
The page to print is displayed fine as a far as the actual web page goes... it scrolls, there are no errors and and nothing seems to be wrong with the page.
When using IE to print, the document just spools with out actually printing out...I end up canceling the document from the printers window.
When viewing print preview the first page is displayed, but when we try to go to the second page in the print preview IE locks up.
This does not happen for every client, but when it does happen it can be reproduced.
The page is pretty long and has client info that is keeping me from just copy and pasting the markup for you guys. I am hopeing that some one else has experienced a similiar issue in IE and has some advice.
NOTE: The users are not allowed to use other browsers, so save the IE flamming please.
Hmmm, very hard to tell without markup.
Just to throw some ideas:
Are you using anything difficult on the pages, like Flash or Java?
Custom fonts / cufon?
Huge downscaled images?
opacity or IE specific crazy filter CSS rules?
A huge structure that IE doesn't manage to break up into pages, e.g. a giant table with position: absolute ?
If you use images, try turning off the images. Try turning off CSS.
A few things to try when debugging:
Switch everything over to a standard font and font size (e.g. Arial 12px).
Eliminate all CSS and JavaScript, and if that fixes it then you can narrow down from there by taking out chunk by chunk until it starts working.
If that doesn't work, try cutting down the content significantly to see if it will show up.
I have a web database app that runs in IE7+ (customer requirement) It is a shop control system that needs to send forms to the printer.
I've got #media print css set up to format the form properly when going from screen to printer. Mostly everything has been working fine.
I've recently added some jquery code to handle placing a footer at the bottom of the page with a variable size table above it. That works as expected except occasionally the footer is thrown to a second page on the printer even though it displays in the proper place on the screen.
So, my question is how can I get print preview to allow me to inspect the document elements so I can figure out what's throwing things off? I've got the IE Developer Toolbar, but it doesn't seem to give access to the print preview.
Thanks for any help.
I would suggest throwing different colored borders on your elements in your #media print css file. This is always useful in debugging layout issues and should show up in the print preview.