I have two classic HTML pages (just HTML and CSS) and links between them.
When I click on these links, the screen flickers (it quickly goes white between transitions).
I tried to place this in the head - without result:
<meta http-equiv="Page-Enter" content="blendTrans(Duration=0.0)" />
<meta http-equiv="Page-Exit" content="blendTrans(Duration=0.0)" />
I can usually open other sites without the flickering.
Browser is Firefox 16.0.1.
Just change your body background to:
body {
background: url("Images/sky01.jpg") repeat scroll 0 0 #121210;
font-family: Verdana,Geneva,sans-serif;
font-size: 12px;
margin: 0;
padding: 0;
}
background color will prevent white flickering while loading the background image.
That meta are for IE only, they don't work in FF.
You can't rely prevent flickering in plain HTML. The best solution I found is to replace every link with a JavaScript call where you download the page with AJAX and then you replace the document itself with the new content. Page refresh will be really fast and you won't see any blank screen while downloading.
Basic function may be something like this:
function followLink(pageUrl)
{
jQuery.ajax({
url: pageUrl,
type: "GET",
dataType: 'html',
success: function(response){
document.getElementsByTagName('html')[0].innerHTML = response
}
});
}
Then you have to replace you links from:
Link
With:
Link
More details about this: replace entire HTML document]1: how to replace the content of an HTML document using jQuery and its implications (not always so obvious).
Improvements
With this solution you force your users to use JavaScript, in case it's not enable they won't be able to click links. For this reason I would provide a fallback. First do not change <a> but decorate them with (for example) a CSS class like async-load. Now on the onload of the page replace all hrefs with their javascript: counterpart, something like this:
jQuery().ready(function() {
jQuery("a.asynch-load").each(function() {
this.href = "javascript:followLink(\"" + this.href + "\")";
});
});
With this you can handle a loading animation too (how it's implemented depends on what yuo're using and your layout). Moreover in the same place you can provide fade in/out animations.
Finally do not forget that this technique can be used for fragments too (for example if you provide a shared navigation bar and a content sections replaced when user click on a link the the navigation bar (so you won't need to load everything again).
Try to embed pictures as it delays final page loading and therefore white transition time
echo '<img src="data:image/png;base64,';
echo base64_encode(file_get_contents($file));
echo '"/>';
Related
I have a page with a few anchors. When a user clicks an anchor, the anchors work, and user is taken to the correct location.
If a user tries to refresh the page, it retains the anchor ID in the URL window and so naturally, when refreshing, it does not go back to the top of the page.
I think it would be more user friendly to go back to the top of the page on a refresh.
How would I achieve this?
My page currently is primarily using bootstrap, css, jquery, javascript, and php.
I think I need to set up some code so that after clicking the anchor, it removes the anchor from the url window, so that if someone refreshes, they'd be refreshing just the initial page state without an anchor, but I don't know how to begin. Or maybe I'm over thinking this and there's some way to always go to top of page on a refresh regardless of anchors or not. I'm not too code savvy.
Right now my code is like this...
An example of one of my anchors:
<a class="hoverlink" href="#firefighter"><li style="float:left; margin-right:1em; color:white; background-color:red" class="appao-btn nav-btn">Fire Fighter</li></a>
One of the elements for example that the anchor will jump to:
<div style="min-height:10px;" name="firefighter" id="firefighter" class="anchor"><p style="min-height: 10px;"> </p></div>
CSS style on my anchors:
.anchor:target { height:200px; display: block; margin-top:-2em; visibility: hidden;}
Actual Results With My Code: Page Refresh Stays At Anchor Location
Desired Results: Page Refresh Goes To Top Of Page
After some searching, I found a solution that almost works for me:
<script>
window.onbeforeunload = function () {
window.scrollTo(0, 0);
}
</script>
But it creates a flickering effect that doesn't look the best such as my example site at
https://graceindustries.com/gracetest/Grace%20Industries%20Website%20Design%202019%20Alternate%20Version/documentation.html
Anyone know how to remove the "flicker"?
You can try this (with the .some-anchor is the class for all a tag that points to some destinations within the page).
$('.some-anchor').click(function() {
var target = $(this).attr("href");
$('html, body').animate({
scrollTop: $("" + target).offset().top
}, 1000);
return false;
});
The "return false;" or preventDefault() event method will prevent the page from flickering. As I observed this does not make the # to the URL so refreshing is not a problem.
Other helpful answer: jQuery flicker when using animate-scrollTo
Navigating to page content using URL Fragments (#someLink) in anchor tags is a core part of the HTML specification. The standard implementation in most (if not all) web browsers is to add the fragment to the address bar. The fragment is part of the URL and therefore, when the page is refreshed the browser scrolls to the element with that ID. Most users will be familiar with this behaviour, even if they don't understand how or why it works like that. For this reason, I'd recommend not working around this behaviour.
However, if it is absolutely necessary, the only way to achieve the result you're looking for is to not use URL fragments for navigation and use JavaScript instead, therefore not putting the fragment in the URL in the first place. It looks like the Element.scrollIntoView() method might do what you're looking for. Rather than having
Click me
you'd use
<a onclick="document.getElementById('element1').scrollIntoView();">Click me</a>
or even better, implement this in an external JS file. If you experience issues due to the element not having the href attribute, you could always add an empty fragment href="#".
You can remove the id from the url right after the user click on the anchor tag
history.scrollRestoration = "manual" will set the scroll to the top of the page on refresh
<a onclick="removeAnchorFormURL()" href="#sec-2">here</a>
<script>
history.scrollRestoration = "manual";
const removeAnchorFormURL = () => {
setTimeout(() => {
window.history.replaceState({}, "", window.location.href.split("#")[0]);
}, 100);
};
</script>
window.location docs
location.href docs
location.replace docs
scrollRestoration docs (check it for info on scrollRestoration compatibility)
How can I control the background image and colour of a body element within an iframe? Note, the embedded body element has a class, and the iframe is of a page that is part of my site.
The reason I need this is that my site has a black background assigned to the body, and then a white background assigned to divs that contain text. A WYSIWYG editor uses an iframe to embed content when editing, but it doesn't include the div, so the text is very hard to read.
The body of the iframe when in the editor has a class that isn't used anywhere else, so I'm assuming this was put there so problems like this could be solved. However, when I apply styles to class.body they don't override the styles applied to body. The weird thing is that the styles do appear in Firebug, so I've no idea what's going on!
Thanks
UPDATE - I've tried #mikeq's solution of adding a style to the class that is the body's class. This doesn't work when added to the main page's stylesheet, but it does work when added with Firebug. I'm assuming this is because Firebug is applied to all elements on the page whereas the CSS is not applied within iframes. Does this mean that adding the css after window load with JavaScript would work?
The below only works if the iframe content is from the same parent domain.
The following code works for me. Tested on Chrome and IE8. The inner iframe references a page that is on the same domain as the parent page.
In this particular case, I am hiding an element with a specific class in the inner iframe.
Basically, you just append a style element to the head section of the document loaded in a frame:
frame.addEventListener("load", ev => {
const new_style_element = document.createElement("style");
new_style_element.textContent = ".my-class { display: none; }"
ev.target.contentDocument.head.appendChild(new_style_element);
});
You can also instead of style use a link element, for referencing a stylesheet resource.
An iframe is a 'hole' in your page that displays another web page inside of it. The contents of the iframe is not in any shape or form part of your parent page.
As others have stated, your options are:
give the file that is being loaded in the iframe the necessary CSS
if the file in the iframe is from the same domain as your parent, then you can access the DOM of the document in the iframe from the parent.
You cannot change the style of a page displayed in an iframe unless you have direct access and therefore ownership of the source html and/or css files.
This is to stop XSS (Cross Site Scripting)
This code uses vanilla JavaScript. It creates a new <style> element. It sets the text content of that element to be a string containing the new CSS. And it appends that element directly to the iframe document's head.
Keep in mind, however, that accessing elements of a document loaded from another origin is not permitted (for security reasons) -- contentDocument of the iframe element will evaluate to null when attempted from the browsing context of the page embedding the frame.
var iframe = document.getElementById('the-iframe');
var style = document.createElement('style');
style.textContent =
'body {' +
' background-color: some-color;' +
' background-image: some-image;' +
'}'
;
iframe.contentDocument.head.appendChild(style);
Override another domain iframe CSS
By using part of SimpleSam5's answer, I achieved this with a few of Tawk's chat iframes (their customization interface is fine but I needed further customizations).
In this particular iframe that shows up on mobile devices, I needed to hide the default icon and place one of my background images. I did the following:
Tawk_API.onLoad = function() {
// without a specific API, you may try a similar load function
// perhaps with a setTimeout to ensure the iframe's content is fully loaded
$('#mtawkchat-minified-iframe-element').
contents().find("head").append(
$("<style type='text/css'>"+
"#tawkchat-status-text-container {"+
"background: url(https://example.net/img/my_mobile_bg.png) no-repeat center center blue;"+
"background-size: 100%;"+
"} "+
"#tawkchat-status-icon {display:none} </style>")
);
};
I do not own any Tawk's domain and this worked for me, thus you may do this even if it's not from the same parent domain (despite Jeremy Becker's comment on Sam's answer).
An iframe has another scope, so you can't access it to style or to change its content with javascript.
It's basically "another page".
The only thing you can do is to edit its own CSS, because with your global CSS you can't do anything.
This should work with cross domain if you're the owner of the both
The trick here is to assign a global css variable to your body, to listen message with the new color, and then to change the global css variable once receive a message.
I'm using angular, but it should work with pure javascript
My use case was to show to the user what he how the color change would impact his website in the iframe before saving it
Domain A
#ViewChildren('iframeContainer') iframeContainer: QueryList<ElementRef>
sendDataToIframe(
data = {
type: 'colorChange',
colors: {primary: '#000', secondary: '#fff'},
},
): void {
if (this.targetUrl)
this.iframeContainer.first.nativeElement.contentWindow.postMessage(data) // You may use document.getElementById('iframeContainer') instead
}
Domain B
acceptedEditOrigins = [
'https://my.origine.ccom', // Be sur to have a correct origin, to avoid xss injecto: https://en.wikipedia.org/wiki/Cross-site_scripting
]
constructor() {
// Listen to message
window.addEventListener('message', (event) => this.receiveMessage(event), false)
}
receiveMessage(event: MessageEvent) {
if (this.acceptedEditOrigins.includes(event.origin))
switch (event.data.type) {
case 'colorChange': {
this.setWebsiteConfigColor(event.data.colors)
}
}
}
setWebsiteConfigColor(colors: WebsiteConfigColors) {
if (colors) {
const root = document.documentElement
for (const [key, value] of Object.entries(colors)) {
root.style.setProperty(`--${key}`, value) // --primary: #000, --secondary: #fff
}
}
}
body {
background-color: var(--primary);
}
If you have control of the page hosting the iframe and the page of the iframe, you can pass a query parameter to the iframe...
Here's an example to add a class to the iframe based on whether or not the hosting site is mobile...
Adding iFrame:
var isMobile=$("mobile").length; //detect if page is mobile
var iFrameUrl ="https://myiframesite/?isMobile=" + isMobile;
$(body).append("<div id='wrapper'><iframe src=''></iframe></div>");
$("#wrapper iframe").attr("src", iFrameUrl );
Inside iFrame:
//add mobile class if needed
var url = new URL(window.location.href);
var isMobile = url.searchParams.get("isMobile");
if(isMobile == "1") {
$("body").addClass("mobile");
}
For juste one iframe, you can do something like this:
document.querySelector('iframe').contentDocument.body.style.backgroundColor = '#1e1e2d';
In case you have multiple iframe you're dealing with:
document.querySelectorAll('iframe').forEach((iframe) => {
iframe.contentDocument.body.style.backgroundColor = '#1e1e2d';
});
Perhaps it's changed now, but I have used a separate stylesheet with this element:
.feedEkList iframe
{
max-width: 435px!important;
width: 435px!important;
height: 320px!important;
}
to successfully style embedded youtube iframes...see the blog posts on this page.
give the body of your iframe page an ID (or class if you wish)
<html>
<head></head>
<body id="myId">
</body>
</html>
then, also within the iframe's page, assign a background to that in CSS
#myId {
background-color: white;
}
We'd like to show a "Loading..." image when the page is still being transferred. Pages can get quite large in our application. I tried with a separate page that displays the image and then loads the intended page, but the animated GIF just stops.
Can something be done on the page itself?
Or is there a better way?
Thanks for your comments, as always!
UPDATE
Here's the general idea of my small switching page:
<?xml version="1.0" encoding="UTF-8"?>
<xp:view xmlns:xp="http://www.ibm.com/xsp/core" xmlns:xc="http://www.ibm.com/xsp/custom">
<xp:div
style="width:84.0px;height:84.0px;position:fixed;top:50%;left:50%;margin-top:0px;margin-left:0px;height:0px;width:0px;z-index:1000"
id="AjaxLoader">
<xp:image url="/loading.gif" id="image1">
</xp:image>
</xp:div>
<xp:scriptBlock id="scriptBlock1">
<xp:this.value><![CDATA[XSP.addOnLoad(function() {
var href= getParameterByName("href");
location.href= href;
});]]></xp:this.value>
</xp:scriptBlock>
</xp:view>
Loading a "loading" page prior than the one you want to load is not an option.
You can create to DIVs in your HTML: one for the loading icon (e.g. with id="loadingIcon"), second one for the content (id="contentWrapper"). The second one is hidden (CSS style="display:none").
Define a Javascript function like this:
function pageLoaded(){
document.getElementById("loadingIcon").style.display = "none";
document.getElementById("contentWrapper").style.display = "";
}
The script is called in the BODY's onLoad event like this:
<body onload="pageLoaded()">
...
</body>
It is not a question of the web-server environment, but how you organize your code :-)
Take your approach and modify it slightly. Instead of location.href = href - which just triggers a reload, use an ajax call and replace your loading div. Something like this:
<xp:scriptBlock id="scriptBlock1">
<xp:this.value><![CDATA[XSP.addOnLoad(function() {
var href= getParameterByName("href");
$.ajax({
url: "test.html",
context: $("#{id:AjaxLoader}");
}).done(function(result) {
$( this ).replace(result);
});
location.href= href;
});]]></xp:this.value>
</xp:scriptBlock>
(contains typos, adjust as needed)
To answer my own question: No, it's not possible, but there is a nice way around this, in my case anyway.
The trick is to open a new browser window, write something in it and then allow the new page to load.
var w= window.open();
w.document.write("<div style='position: fixed; top: 48%; left:40%'>Loading...</div>");
w.location.href= url;
If necessary the text can be replaced by an image and the new url can be set after a timeout.
How can I control the background image and colour of a body element within an iframe? Note, the embedded body element has a class, and the iframe is of a page that is part of my site.
The reason I need this is that my site has a black background assigned to the body, and then a white background assigned to divs that contain text. A WYSIWYG editor uses an iframe to embed content when editing, but it doesn't include the div, so the text is very hard to read.
The body of the iframe when in the editor has a class that isn't used anywhere else, so I'm assuming this was put there so problems like this could be solved. However, when I apply styles to class.body they don't override the styles applied to body. The weird thing is that the styles do appear in Firebug, so I've no idea what's going on!
Thanks
UPDATE - I've tried #mikeq's solution of adding a style to the class that is the body's class. This doesn't work when added to the main page's stylesheet, but it does work when added with Firebug. I'm assuming this is because Firebug is applied to all elements on the page whereas the CSS is not applied within iframes. Does this mean that adding the css after window load with JavaScript would work?
The below only works if the iframe content is from the same parent domain.
The following code works for me. Tested on Chrome and IE8. The inner iframe references a page that is on the same domain as the parent page.
In this particular case, I am hiding an element with a specific class in the inner iframe.
Basically, you just append a style element to the head section of the document loaded in a frame:
frame.addEventListener("load", ev => {
const new_style_element = document.createElement("style");
new_style_element.textContent = ".my-class { display: none; }"
ev.target.contentDocument.head.appendChild(new_style_element);
});
You can also instead of style use a link element, for referencing a stylesheet resource.
An iframe is a 'hole' in your page that displays another web page inside of it. The contents of the iframe is not in any shape or form part of your parent page.
As others have stated, your options are:
give the file that is being loaded in the iframe the necessary CSS
if the file in the iframe is from the same domain as your parent, then you can access the DOM of the document in the iframe from the parent.
You cannot change the style of a page displayed in an iframe unless you have direct access and therefore ownership of the source html and/or css files.
This is to stop XSS (Cross Site Scripting)
This code uses vanilla JavaScript. It creates a new <style> element. It sets the text content of that element to be a string containing the new CSS. And it appends that element directly to the iframe document's head.
Keep in mind, however, that accessing elements of a document loaded from another origin is not permitted (for security reasons) -- contentDocument of the iframe element will evaluate to null when attempted from the browsing context of the page embedding the frame.
var iframe = document.getElementById('the-iframe');
var style = document.createElement('style');
style.textContent =
'body {' +
' background-color: some-color;' +
' background-image: some-image;' +
'}'
;
iframe.contentDocument.head.appendChild(style);
Override another domain iframe CSS
By using part of SimpleSam5's answer, I achieved this with a few of Tawk's chat iframes (their customization interface is fine but I needed further customizations).
In this particular iframe that shows up on mobile devices, I needed to hide the default icon and place one of my background images. I did the following:
Tawk_API.onLoad = function() {
// without a specific API, you may try a similar load function
// perhaps with a setTimeout to ensure the iframe's content is fully loaded
$('#mtawkchat-minified-iframe-element').
contents().find("head").append(
$("<style type='text/css'>"+
"#tawkchat-status-text-container {"+
"background: url(https://example.net/img/my_mobile_bg.png) no-repeat center center blue;"+
"background-size: 100%;"+
"} "+
"#tawkchat-status-icon {display:none} </style>")
);
};
I do not own any Tawk's domain and this worked for me, thus you may do this even if it's not from the same parent domain (despite Jeremy Becker's comment on Sam's answer).
An iframe has another scope, so you can't access it to style or to change its content with javascript.
It's basically "another page".
The only thing you can do is to edit its own CSS, because with your global CSS you can't do anything.
This should work with cross domain if you're the owner of the both
The trick here is to assign a global css variable to your body, to listen message with the new color, and then to change the global css variable once receive a message.
I'm using angular, but it should work with pure javascript
My use case was to show to the user what he how the color change would impact his website in the iframe before saving it
Domain A
#ViewChildren('iframeContainer') iframeContainer: QueryList<ElementRef>
sendDataToIframe(
data = {
type: 'colorChange',
colors: {primary: '#000', secondary: '#fff'},
},
): void {
if (this.targetUrl)
this.iframeContainer.first.nativeElement.contentWindow.postMessage(data) // You may use document.getElementById('iframeContainer') instead
}
Domain B
acceptedEditOrigins = [
'https://my.origine.ccom', // Be sur to have a correct origin, to avoid xss injecto: https://en.wikipedia.org/wiki/Cross-site_scripting
]
constructor() {
// Listen to message
window.addEventListener('message', (event) => this.receiveMessage(event), false)
}
receiveMessage(event: MessageEvent) {
if (this.acceptedEditOrigins.includes(event.origin))
switch (event.data.type) {
case 'colorChange': {
this.setWebsiteConfigColor(event.data.colors)
}
}
}
setWebsiteConfigColor(colors: WebsiteConfigColors) {
if (colors) {
const root = document.documentElement
for (const [key, value] of Object.entries(colors)) {
root.style.setProperty(`--${key}`, value) // --primary: #000, --secondary: #fff
}
}
}
body {
background-color: var(--primary);
}
If you have control of the page hosting the iframe and the page of the iframe, you can pass a query parameter to the iframe...
Here's an example to add a class to the iframe based on whether or not the hosting site is mobile...
Adding iFrame:
var isMobile=$("mobile").length; //detect if page is mobile
var iFrameUrl ="https://myiframesite/?isMobile=" + isMobile;
$(body).append("<div id='wrapper'><iframe src=''></iframe></div>");
$("#wrapper iframe").attr("src", iFrameUrl );
Inside iFrame:
//add mobile class if needed
var url = new URL(window.location.href);
var isMobile = url.searchParams.get("isMobile");
if(isMobile == "1") {
$("body").addClass("mobile");
}
For juste one iframe, you can do something like this:
document.querySelector('iframe').contentDocument.body.style.backgroundColor = '#1e1e2d';
In case you have multiple iframe you're dealing with:
document.querySelectorAll('iframe').forEach((iframe) => {
iframe.contentDocument.body.style.backgroundColor = '#1e1e2d';
});
Perhaps it's changed now, but I have used a separate stylesheet with this element:
.feedEkList iframe
{
max-width: 435px!important;
width: 435px!important;
height: 320px!important;
}
to successfully style embedded youtube iframes...see the blog posts on this page.
give the body of your iframe page an ID (or class if you wish)
<html>
<head></head>
<body id="myId">
</body>
</html>
then, also within the iframe's page, assign a background to that in CSS
#myId {
background-color: white;
}
How to make tabs on the web page so that when click is performed on the tab, the tab gets css changed, but on the click page is also reloaded and the css is back to original.
dont use the jquery :D
all of what you needs a container, a contained data in a varable and the tabs
the container is the victim of the css changes.
the tabs will trigger the changing process.
if you have a static content, you can write this into a string, and simply load it from thiss.
if you have a dinamically generated content, you need to create ajax request to get the fresh content, and then store it in the same string waiting for load.
with the tabs you sould create a general functionusable for content loading.
function load(data) {
document.getElementById("victim").innerHTML = data;
}
function changeCss(element) {
//redoing all changes
document.getElementById("tab1").style.background="#fff";
document.getElementById("tab2").style.background="#fff";
element.style.background = "#f0f";
}
with static content the triggers:
document.getElementById("tab1").onclick = function() {load("static data 1");changeCss(document.getElementById("tab1"))};
document.getElementById("tab2").onclick = function() {load("static data 2");changeCss(document.getElementById("tab2"))};
if you want to change the css, you need another function which do the changes.
i tell you dont use the jquery because you will not know what are you doing.
but thiss whole code can be replaced by jquery like this:
$("tab1").click(function(e) {
$("#tab1 | #tab2").each(function() {
$(this).css("background","#fff"); });
$(this).css("background","#00f");
$("#victim").append("static content 1");
});
$("tab12click(function(e) {
$("#tab1 | #tab2").each(function() {
$(this).css("background","#fff"); });
$(this).css("background","#00f");
$("#victim").append("static content 2");
});
if you know how javascript works then there is noting wrong with the jquery, but i see there is more and more people who just want to do their website very fast and simple, but not knowing what are they doing and running into the same problem again and again.
Jquery UI Tabs:
http://jqueryui.com/demos/tabs/
Have a <A href tag around the "tab" and use onClick to fire some Javascript that changes the CSS.
If you do not want use Jquery for creating of UI tabs, please see my cross-browser JavaScript code: GitHub.
You can use different ways to create tabs and tab content.
Tab content can added only when tab gets focus.
You can remember selected tab. Selected tab opens immediatelly after opening of the page.
You can create tabs inside tab.
Custom background of the tab is available.
Example: Tabs