How to make images appear in Javascript - javascript

I'm not very fluent in javascript, and I feel like this is really basic, but I can't seem to find it online anywhere.
I want to create a link that will trigger a javascript function that makes an image appear in a separate div. It can't be in flash, otherwise I have no objection to the coding language.
I have several images, so I would think that the best way to do this would be to layer them all on top of each other and then increase the z-index each time their link is clicked, but you might have a better idea.
I really just want someway to create a sort of primitive image gallery that doesn't use flash and displays the photo in its div when the corresponding link is clicked.
Thanks in advance, Alex

As Jessegavin said (found here)
You could make use of the Javascript DOM API. In particular, look at
the createElement() method.
You could create a re-usable function that will create an image like
so...
function show_image(src, width, height, alt) {
var img = document.createElement("img");
img.src = src;
img.width = width;
img.height = height;
img.alt = alt;
// This next line will just add it to the <body> tag
document.body.appendChild(img);
}
Then you could use it like this...
<button onclick="show_image('http://google.com/images/logo.gif',
276,110, 'Google Logo");'>Add Google Logo</button>
There shouldn't be a line break above, I added it so that it could
show without scrolling See a working example on jsFiddle:
http://jsfiddle.net/Bc6Et/
This should answer your question

There are a ton of javascript libraries, plugins (for jQuery) and other ways of solving this problem.
First thing I would do is to peruse a website like this, to see what's available: http://sixrevisions.com/javascript/free_javascript_image_galleries/
I have used this one before, and it's pretty straight forward: http://lokeshdhakar.com/projects/lightbox2/
In general though you can just do Link and clicking that will call the javascript function showImage() that you define somewhere. Then layering the divs will work as you have described.

Related

How to add another image modal (W3S-code)?

I found this code in W3S:
https://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_modal_img
I can't figure out how to add another image modal next to the existing image.
And I bet this is easy for people who understand javascript, unfortunately I don't and would be so happy if someone explained.
Thanks!
The problem with the code they supplied is that the JavaScript relies on an image ID, which you can only have one of in the entire document.
By mainly swapping out the;
var img = document.getElementById('myImg');
with;
var imageList = document.querySelectorAll('img');
and looping on the results you will be able to add multiple images.
I updated the code as an example with two images on JSFiddle hopefully you will find that useful.

images being replaced when I want the next image just added

I have a javascript function which animates images like a slide show. What I'd like is to just have the images being displayed one after another from left to right.
I can't seem to find where in the code the images is getting replaced.
var realoffset = d.offset % d.total;
$(this)
.html(d.titles[realoffset])
.attr('action','article:'+(realoffset+1))
.fadeIn(600);
$(this)
.siblings('img')
.attr('src',function(i,attr){
return attr.replace(
/.+(\/large\/[a-zA-Z\.-_]+)$/,
d.locations[realoffset]+'$1'
)
})
.attr('action','article:'+(realoffset+1))
.fadeIn(600);
.attr('src',function(i,attr){
return attr.replace(
/.+(\/large\/[a-zA-Z\.-_]+)$/,
d.locations[realoffset]+'$1'
)
})
This code is replacing the src of the img tag. You're going to want to be inserting new img tags to show them side by side, not replacing the current tag's src.
Did you write that jQuery snippet yourself? I'm guessing not. Anyway, there are a lot of factors involved in creating a "slideshow" with JavaScript. It sounds like you just need some general knowledge about the subject.
First, let's get your vision straight. Based on your code, you seem to want to fade images into view as they are cycled in the slideshow. For that, study this example:
http://jsfiddle.net/Y6fnx/1/
Now, your code does stuff with d.titles; purely by inference I'm guessing that this displays the image and also a caption for the image? For that, study my updated fiddle:
http://jsfiddle.net/ESP9S/1/
There are countless ways to create a slideshow! You can implement auto-play by taking advantage of JavaScript's setTimeout. You can load your captions from somewhere else. You can get your images from a external script (like Barbara mentioned). You can slide your images instead of fading them by playing with jQuery animate. It never ends!

Image gallery pagination

I have created the following image gallery.
http://jsfiddle.net/sfiddle/Nf7yR/7/
I think the thing is, that even though I can get a hand on the paragraphs css, the currentIndex won't update, i.e. an event listener seems to be missing.
var thumb = document.getElementById("thumb");
myParagraphs = thumb.getElementsByTagName("p");
console.log(myParagraphs[1]);
function thumby(){
$(myParagraphs[currentIndex]).css("background-color", "red");
}
thumby();
The thing is that I can not manage to link the image index with the index of the pagination dot (which has a normal p tag).
I want to code it in that way that if the first picture is displayed the first dot is red, if the second image is displayed the second ...
How could I approach this?
Thanks for any good advice as I invested a few hours already but can not get my head around it.
PS: no, I want no plugin or ready made imagegallery, I want my approach to work :-)
You made a function thumby() but you are calling it only once (during script start). You just need to call it when you change currentIndex. Here you have fixed code: http://jsfiddle.net/Nf7yR/10/ (I commented my edits).
BTW your code looks terrible. You should indent it properly to make it easier to read :)

How can I determine img width/height of dynamically loaded images in IE?

My markup is a simple div element with id 'load'. Using jQuery I then load a list of image elements into this div:
$('#load').load('images.html', { }, function() {
$(this).onImagesLoad({
selectorCallback: function() {
....do something....
}
});
});
where images.html is a list like this:
<img src='1.jpg' caption='img 1'>
<img src='2.jpg' caption='img 2'>
...
To ensure that all images are loaded completely, I use the onImagesLoad plugin. This, so far, works just fine on all browsers.
However, on IE8 (and I assume other versions of IE also) when I then iterate over the img elements, I am unable to determine the width/height of the images loaded. The image.context.naturalWidth and naturalHeight attributes don't seem to work.
How do I get a hold of the images' dimension?
Thanks heaps :)
Update
#Simon: That didn't work on IE, and broke the other browsers as well.
#Jenechka: If "imageDomElement" is just another name for the "image" variable in my example above, then it doesn't work. Or what do you mean by that DomElement?
If you haven't resized the image, you could use:
image.width()
and
image.height()
It's been a while but I finally found some time to tinker with this again. The above problems are still there, but here is what I think is going on.
When I load the initial images then yes, the file is loaded and image objects are generated. But it seems that the attributes are not correct yet, and they won't be until the image is actually added to the DOM of the site and rendered. A div/image on hide() on IE has no dimension information whatsoever, on Safari there is some information available. For example, without adding the following div anywhere
var test = $("<div><img src='test.jpg'></div>")
the image contained there has the following information:
width() = 0,
attr("width") = 600,
css("width") = "", and
img[0].clientWidth = 0.
That's on Safari; on IE it's the same except attr("width") = 0 and css("width") = "auto". Now I can't use this, and that's what broke my script and why I posted my initial question. However, the moment I append this div and have it rendered, all the correct values show up in the image object.
I'm writing a little gallery thinghie, which shows whatever images I have in that second .html file that I load; that gallery, however, computes and places the thumbnails, and prepares the images it shows in full resolution. To make this look ok, I basically wanted to create the entire thing hidden, and then fade it in. Alas, it seems that this whole idea won't pan out. A friend suggested to load everything into a tiny iframe off to the left where it's not visible, and work with that. Perhaps that's the way to go.
Another thing I noticed, and that seems to be very closely related to the aforementioned load issue is clone(). It seems that if an image is rendered, a
var newimg = img.clone()
generates the same "empty" image object that I have to deal above. Even when the original image is visible and contains all the right attributes, its clone does not.
Right now I don't see any other way than to rethink and rewrite parts of my gallery.
This is quite similar to the other answers, but I have tested it in IE7, so it might be closer to what you want:
$(document).onImagesLoad({
selectorCallback: function() {
$('img').each(function(){
alert($(this).width()+', '+$(this).height());
});
}
});
See here, this may not be exactly how you were using it, but I'm not familiar with this onImagesLoad thing.
imageDomElement.width
imageDomElement.height
or try
imageDomElement.clientWidth
imageDomElement.clientHeight
If you play with jquery, then image.attr(width) should do the trick
But why not using the document.ready instead, could give you less headeache. .
Use the following code instead
$(document).onImagesLoad({
selectorCallback: function() {
$('img').each(function(){
alert($(this)[0].clientWidth +', '+$(this)[0].clientHeight);
});
}
});
What about?
$("#load img").each(function() {
var img = new Image();
img.src = this.src;
alert(img.height + " x " + img.width);
});

how to get a js png fix to work on ajax calls

we're using js to do png replacement, and we also have ajax updates on some of these elements. when the page fragment gets updated, the png fix gets lost, since the png fix traverses the dom and replaces png bg images when the document loads. is there a way to render the png replacement when the ajax update takes place, rather than only on document.onload? we're using jquery.
Are you using behavior?
If you are using iepngfix.htc, you might try setting the behavior inline
var myEl = document.getElementById('inbound-ajax-element');
myEl.style.behavior = 'url(iepngfix.htc)';
http://www.twinhelix.com/css/iepngfix/demo/
You should take a look here jQuery IE PNG Fix Plugin
jQuery(function($) {
$("img[#src$=png], #image-one, #image-two").pngfix();
});
You should run this on the images you just loaded.
http://abcoder.com/javascript/ie6-png-alpha-transparency-fix-for-dynamically-loaded-images-via-ajax/
The link above provides an example that attaches the PNG fix to the image's onload event, for example:
new_img.onload = function(){
ti.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + timg_src + "', sizingMethod='scale')";
ti.setAttribute('src', 'blank.gif');}
The reason it gets lost is that the pngfix is not something that is applied continually, it is applied on page load to the items present, and so if you change one of them or create new png's the pngfix will not be applied.
So in your javascript where you create the image, you need to follow it up by applying the pngfix to that item.
How that javascript will look is dependent on what kind of pngfix you're using. There are other answers here which give examples of what to apply after you add the new image.

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