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JavaScript - Image Preload Question (just Starting To Learn)
Hi! I'm just starting to learn java script and have a questions. If anyone could answer this it'd be great.
When preloading images for use in things like mouseout/on/etc what is the proper code? var image1, image 2; image1 = new Image() image1.src = "" image2 = new Image() image2.src = "" OR var image1 image1.... var image2 image2.... The book I have list both but only the 2nd way I listed works. Why? Thanks Similar TutorialsHi, I am completely aware that Framesets are an outdated way of designing these days (I don't have time to redesign the site now), but I have a question:. Is there a way I can have a "Please wait.. Loading.." message of some sort on the "contents.html" frameset? It takes a while to load.. Code: <html> <head> </head> <frameset rows="130,*" framespacing="0" border="0" frameborder="0"> <frame name="banner" scrolling="no" noresize target="contents" src="title.html"> <frameset cols="523,493"> <frame name="contents" target="main" src="contents.html" scrolling="auto"> <frame name="main" src="letters.html" scrolling="auto"> </frameset> <noframes> <body> <p>This page uses frames, but your browser doesn't support them.</p> </body> </noframes> </frameset> </html> Thanks so much. I want to use an image as a CSS background-image so I used the Image constructor to load the image: Code: (new Image()).src="http://www.mediafire.com/imgbnc.php/432b35f2cc3340ea03d25128ada294476c92189353679dfb7e9cc9dfde6498f06g.jpg"; but I noticed that the browser (Firefox) load the image from the URL and not from the memory when changing the background-image property (it takes about 1.5 seconds before showing the image, and every time I reload the page!) I have more than a hundred images (small ones though), which is a cut-to-pieces large image arranged in tables that I want to preload. I have been looking for a preload script that could possibly load all images in a folder by wildcard and if possible via JavaScript. Any suggestions? Any other language will be welcome as long as it will run on Linux. I have a good preload javascript here that I downloaded from hotscripts.com that displays a progress bar, percentage of download, and number of images downloaded. The bad thing is that creating an array out of a hundred images will be tedious especially with computer genereted filenames! If anyone knows of a program that could automate the process then we can forget the wildcard! Hehe! Hope someone has ideas . Thanks in advance. Hello All! Brand new to Javascript here, so please forgive my basic question. I did a search but did not find exactly what I was looking for. My web site has a splash page with a large image broken into pieces and displayed in a table. I want to preload the images so the user doesn't see the table slowly "fill in" when using a slower internet connection. I have written a basic script, using the basic format of: <SCRIPT LANGUAGE="JavaScript"> Image1= new Image(50,60) Image1.src = "something.gif" Image2 = new Image(70,80) Image2.src = "somethingelse" Image3 = new Image(90,100) Image3.src = "lastsomething.gif" </SCRIPT> and saved it as a .js file and placed it in my sites root directory. Just to be safe, I've placed the images there too. (do I have to do that though?) Still, it does not seem to be working. Below is the head from my splash page. Have I missed somthing here? I thought that by putting the script reference in the head, the images would be loaded before the table came up, but such does not seem to be the case. Any help would be most appreciated. Thanks! <html> <head> <title>Finish Well Endurance</title> <meta name="generator" content="Namo WebEditor"> <link type="text/css" rel="stylesheet" href="http://www.fwe1.net/css/index.css"> <script type="text/javascript"language="javascript"src="loadimages.js"></script> </head> <body bgcolor="#464646" text="black" link="#464646" vlink="#464646" alink="#464646"> <table border="0" align="center" cellpadding="0" cellspacing="0" width="600"> Hello, I've some javascript code which preload the images for a photo gallery made of clickable thumbnails and the images to be shown. The script is structured to preload the images in order to have a smooth experience while browsing through the thumbnails but, as the images are needed in quite high quality and can't be compressed any further, the page is too slow to load. Basically, as the script sits between the head tags at the beginning of the page, it holds the loading of the whole page, leaving the user with a black page for a good 10 seconds on a fast connection. Is there any chance I can preload the images in such a way I don't have to hold the whole page from displaying while the images are loaded? It would be ideal to be able to display the contents of the page (logo, menu, 1st picture of the gallery and foot of the page) while the images preload in the background. Could please anybody help with this? Here is the code I'm using: <SCRIPT language=JavaScript1.1> var myimages=new Array() function preloadimages(){ for (i=0;i<preloadimages.arguments.length;i++){ myimages[i]=new Image() myimages[i].src=preloadimages.arguments[i] } } preloadimages("images/gallery/editorial/1.jpg","images/gallery/editorial/2.jpg","images/gallery/editorial/3.jpg","images/gallery/editorial/4.jpg","images/gallery/editorial/5.jpg","images/gallery/editorial/6.jpg","images/gallery/editorial/7.jpg","images/gallery/editorial/8.jpg","images/gallery/editorial/9.jpg","images/gallery/editorial/10.jpg","images/gallery/editorial/11.jpg","images/gallery/editorial/12.jpg","images/gallery/editorial/13.jpg","images/gallery/editorial/14.jpg","images/gallery/editorial/15.jpg","images/gallery/editorial/16.jpg","images/gallery/editorial/17.jpg","images/gallery/editorial/18.jpg","images/gallery/editorial/19.jpg","images/gallery/editorial/20.jpg","images/gallery/editorial/21.jpg","images/gallery/editorial/22.jpg","images/gallery/editorial/23.jpg","images/gallery/editorial/24.jpg","images/gallery/editorial/25.jpg") function MM_swapImgRestore() { //v3.0 var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc; } function MM_preloadImages() { //v3.0 var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array(); var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++) if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}} } function MM_findObj(n, d) { //v4.01 var p,i,x; if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) { d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);} if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n]; for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document); if(!x && d.getElementById) x=d.getElementById(n); return x; } function MM_swapImage() { //v3.0 var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3) if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];} } </SCRIPT> and this is for the thumbnails: <a onmousedown='changeimage(myimages[0],this.href)'><img src="images/gallery/thumb1.gif" alt="1" width="16" height="16" border="0" /></a> <a onmousedown='changeimage(myimages[1],this.href)'><img src="images/gallery/thumb2.gif" alt="2" width="16" height="16" border="0" /></a> <a onmousedown='changeimage(myimages[2],this.href)'><img src="images/gallery/thumb3.gif" alt="3" width="16" height="16" border="0" /></a> <a onmousedown='changeimage(myimages[3],this.href)'><img src="images/gallery/thumb4.gif" alt="4" width="16" height="16" border="0" /><br /> </a> etc.... Any help would be much appreciated. Thanks paolo Hi! I have a website that requires preloading images a lot. I would like to preload only the most important images first and display the page as quickly as possible. After that it will take at least 20 seconds before the user will need the rest of the images. Is there a way of making two preloading groups and have the second group load in background after the page is already visible? My current preload code is simply like this: <SCRIPT language="JavaScript"> if (document.images) { pic01= new Image(200,200); pic01.src="images/base.jpg"; pic02= new Image(200,200); pic02.src="images/grump1.jpg"; pic03= new Image(200,200); pic03.src="images/grump2.jpg"; pic04= new Image(200,200); pic04.src="images/grump3.jpg"; pic05= new Image(200,200); pic05.src="images/grump4.jpg"; pic06= new Image(200,200); pic06.src="images/love.jpg"; pic07= new Image(200,200); pic07.src="images/smile1.jpg"; pic08= new Image(200,200); pic08.src="images/smile2.jpg"; pic09= new Image(200,200); pic09.src="images/smile3.jpg"; pic10= new Image(200,200); pic10.src="images/smile4.jpg"; pic10= new Image(200,200); pic10.src="images/rotate.gif"; } </SCRIPT> Hi all If I pre-cache imgs like this ... (10 in all) Code: <head> <script type="text/javascript"> PreImage1= new Image(width,height); PreImage1.src = "images/navbtn/onbtn_1.gif"; PreImage2 = new Image(width,height); PreImage2.src = "images/navbtn/onbtn_2.gif"; PreImage3= new Image(width,height); PreImage3.src = "images/navbtn/offbtn_1.gif"; PreImage4 = new Image(width,height); PreImage4.src = "images/navbtn/offbtn_2.gif"; </script> Will imgs be read from cache if I then do this?... or have I missed smthg? Code: <body> <img src="images/navbtn/offbtn_1.gif" onmouseover=this.src="images/navbtn/onbtn_1.gif" onmouseout=this.src="images/navbtn/offbtn_1.gif" alt="" /> </div> low tech Hi Everyone, I have created 8 thumbnails of their larger full sized pictures. Next I created a "picdiv" with CSS attributes within a center division. The thumbnails sit just above the "picdiv". I need code to open the full pictures in the "picdiv" when I click on the thumbnail. I've tried an on-click function but can't get this working either. Can anyone help please? Anita Hello, I'm not sure if this is the best forum for my question or not, but I'll explain what I'm doing and we'll see. I am trying to make a little easter egg hidden inside a web application and its going great except I'd like to hide my .gif files by changing their file extension to something like .dat instead so it won't be so obvious what they are. Basically all I really want to do is have an html image tag that points to a file who's extension is not gif, but really does contain gif content. (I want to mask the fact that the file is really a gif when looking at it in the directory listing.) So, my idea was I would point the <img src=""> tag's src attribute to a cgi script that could write out a Content-type: image/gif header and return the binary gif data. So, I did this and it worked great, but its really slow. (I output the image multiple times and animate it.) So, I thought I could maybe use Javascript to preload these cgi requests and cache them, but every attempt I've made to do this fails! It's like the browser doesn't want to cache the cgi requests. My method of attempting this was to create Image() objects in javascript and set their src attribute to my cgi script call and then set an onload to keep track of when they were all loaded. That seemed to work fine, but then when I try to display an image with the src tag equal to the cgi location (after they were all loaded) its like it goes and reads the code to pull it down again instead of using a cached copy because its really slow. So, then I thought, hey maybe I could just manually edit the binary content of the gif file (which has an extension like .dat) to also contain Content-type: image/gif\n\n embedded at the front of the file. So, I opened the binary file with a hex editor and inserted that text content at the front... but it didn't work. I had <img src="myfile.dat"/> Is there an easy way to make the browser recognize my gif file even if I don't use a gif extension? If not is there a way to preload and cache cgi responses with Javascript so that they don't keep reloading each time I refer to them? Any other ideas? Thanks.
Hey, I'm a javascript newbie and am frankensteining various bits of code I have managed to find on Lightboxes, preloading, and swapping image Basically, what I want to happen is to run the mouse over the thumbnails on the left side of the page and a larger version of that is in the middle, while information on the right changes to match the picture in the middle. The information is working and the thumbnails appear to be working- at least they go white when running the mouse over them. The problem is the center images aren't appearing at all. I think the following is the relevant information. Code: function MM_preloadImages() { //v3.0
var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}
function MM_findObj(n, d) { //v4.01
var p,i,x; if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
if(!x && d.getElementById) x=d.getElementById(n); return x;
}
function MM_swapImage() { //v3.0
var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}
function MM_setTextOfLayer(objId,x,newText) { //v9.0
with (document) if (getElementById && ((obj=getElementById(objId))!=null))
with (obj) innerHTML = unescape(newText);
}
Code: <img src="imagetmb.jpg" name="boxd" id="boxd" onmouseover="MM_swapImage('boxd','','whitebox.jpg','','image.jpg',1);MM_setTextOfLayer('info','','Info<br /><br />Ink on Bristol Paper<br/><br />13 x 17 in<br /><br>May 2011<br/>')" onmouseout="MM_swapImage('boxB','','imagetmb.jpg',1)"/>
I think it's because the images in the center don't have a source, only a name, but I'm not sure where I would fit that in. I tried putting it in the second set of code, but it did not work out. Hello, First time on the forum and I am admittedly a complete noob, so forgive me for any grievous misconceptions. I am a teacher trying to create a bulletin board on my website where students, teachers, and parents can post messages. I am trying to use the site linoit.com I am trying to embed that site on my website using an iframe url: http://www.capretto.net/stickyboard.shtml My problem is that when you go to the message board on my site it asks your for a username and password to login to access my message board from linoit. I was hoping there is a scripts or other trick that will auto fill the username and password when the page loads so that the message board opens automatically. Not too worried about privacy, but I could distribute the username and password to all interested parents, teachers, etc. but in my experience one more step between students and the information they need can be the difference between them not receiving the info. I'd be happy to give any contributors credit on my site for their coding help. Thanks in advance. OK so I have a simple fare I have to compute. There is a start zone and an end zone. There are 3 separate zones so 9 different charges. Plus there are charges for minutes too 0-4, 4-10, 10-20 and 20 to no limit. The user will input 3 parameters the start and end zone and the time. This would be a JS file. HELP
Hey i need some help delaying this script so it starts 5 seconds after the page loads not instantly. <script> $('#ad_1 > img').each(function(i,e){ rotate($(this),600,4000,i); }); function rotate(elem1,speed,timeout,i){ elem1.animate({'marginLeft':'18px','width':'0px'},speed,function(){ var other; if(elem1.parent().attr('id') == 'ad_1') other = $('#ad_2').children('img').eq(i); else if(elem1.parent().attr('id') == 'ad_2') other = $('#ad_3').children('img').eq(i); else if(elem1.parent().attr('id') == 'ad_3') other = $('#ad_1').children('img').eq(i); other.animate({'marginLeft':'0px','width':'35px'},speed, function(){ var f = function() { rotate(other,speed,timeout,i) }; setTimeout(f,timeout); }); }); } }); </script> hi guys, I'm having a bit of trouble with javascript... I'm searching for a string that starts with another string code: for (x in products ){ s = products[x].id.toString(10); v = "/\b"; v += idValue.toString(10); v += "/g"; alert(v); found = s.match(v); alert(found); } the variables are integers but since i'm searching for the beginning only i turned them into strings... the problem occurs when I add the \b it turns out gibberish.. any help will be gladly appreciated. p.s. if there is a faster way to do it without turning the variables to string also would be great to know. I just know 2 sites below: http://devsnippets.com/ http://www.dynamicdrive.com/ Hi guys I'm new to the forums here. I want to learn how to use Javascript and AJAX along with jquery or prototype to develop a dynamic website. For example, I like how www.dropbox.com works. Everything has a transition, and you can drag and drop things around which is what I like. Ultimately I hope to be able to develop a dynamic website with social networking elements. I know my goals are lofty, but where should I get started and what should I learn. I have some cursory programming experience with visual basic, fortran and html. Any particular books that would help me learn. Ideally a book would have some programming "challenges" or small projects that would give me some experience. Thanks Hello, I'm currently taking a JavaScript class at a local community college and my whole learning experience with it has been horrendous. I'm doing horrible in the class and the book we use is just beyond horrible. The book we use is called JavaScript and ajax 2nd edition. The first assignment we had to do had us putting an array in a function. Other programming classes uses books that start out slow this one just jumps right into it and is all disorganized. I have taken Java and Python and passed both classes with a B but for some reason I'm struggling really bad in this class. I wanted to be a web developer but I feel like it's slowly fading away because of the difficulty of the course. What are some better ways I can learn JavaScript? I have heard of code academy, tree house, and code school and tried code academy but I felt like it was just mainly copying code and I want to get more out of it. How did you guys learn JavaScript..Was it self taught or through school? I really thought that JavaScript would be easier than learning java and python but I feel like it's not. Thanks for your help..I need some words of encouragement. lol
Hello! I have wanted to learn JS/PHP/MySQL for like six-seven years and I have in periods quitted and started with HTML/CSS because I always find CSS as an obstacle. I am a perfectionist, so I want everything to be perfect and I get frustrated when I don't know when to use %, px, em, when to use bla and bla.. And besides, I suck at design. I don't have an eye for that. I just want to get started with the fun stuff - get some interaction with the user. Can I start learning JS without really mastering CSS and then hopefully get back to CSS afterwards? And would I want to learn JS or jQuery at first? Thanks! Hi all, working on building a website at the moment. and i need to create a script that will increment a number by 0.01, then stop and decrease by 0.03, then increase again by one. I wrote code to increment by 0.01 continuouly but now i can't stop it. and change to decreasing <script type = "text/javascript"> num = 0.87; var tim = 0; function makeNum() { num = ((num*1) + .01).toFixed(2); document.getElementById('count').innerHTML = num-.01; tim = window.setTimeout("makeNum()", 2000); } makeNum(); </script> And now I'm Completly stuck. Help would be grately appreciated Thanks |
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