Display Binary Image In Web Page Using Response Object?
Sep 3, 2010
I am using javascript as the scripting language in an asp page. I would like to write the binary image into the web page using javascript. I am able to do this using vbscript as below,<%@ Language=VBScript %>
I've search far and wide for an answer, so forgive me if this is a stupid question. (Well, it probably is.)
Consider the following javascript:
var foo = new Image(); foo.src = "http://some.server.com/some_filename.gif";
Now, the browser will retrieve 'some_filename.gif' from some.server.com and put it into the object foo. What I want to do is then subsequently analyze the actual binary data contained inside some_filename.gif. (Specifically, I just need to look at the first few bytes.) Is there any way to do this in just JavaScript?
I'm trying to get the binary data of an image object.
I've found articles to writing binary to be the source of an image, but they don't tell you how to do the reverse. Pretty much, after the page loads I want to do something like.
For those that are curious why I'm doing this its for another project I'm working on where I store the binary data somewhere else after load, but for technical reasons this has to be done client side for if I do it server side I'm not getting the results I need for this project.
According to my previous post with popups hanging, now I'm trying to bypass this strange behaviour using loading JavaScript image not by image.src=URL but straight away from stream using HTTP GET method.
The problem is, how to assign stream from downloaded image (ex. GIF89a) to a JavaScript Image object ? Code:
Im trying to implement dynamic images on my site. Basically, there is a list box, and when the user selects an option, it calls a service that streams back a base64 encoded image that will be the preview of what they're looking at.in FF you can do this: img.src = "data:image/png;base64," + args ; This doesnt work for IE. from what ive learned, IE doesnt support this type of inline coding.
I was thinking that maybe the next best solution would be to convert the base64 back into binary, and set the new image object to that source. something like this:
Code:
var img = new image(); img.source = binarydata;
now obviously, img.source isnt a real method. but i would like to be ale to set the binary data as the image.
possiblities: Is there anyway to save that binary as a file on the client? and then be able to reference that file as the picture img.src = "images/" + newfilename;
Some other alternatives is to stream back a reference on the server to get the picture, this would require two callbacks, which i dont want.
Also, there is a method of turning the image into a big array of HTMl elements, and each element holds a color, being a pixel. im not doing that, that is the biggest hack job i have ever seen.
I have created a servlet that does nothing more than create a XML file.i have got some JQuery code that reloads the servlet to get the XML data.This works fine and i am able to load the data i want, the problem i have is that when the data is loaded to the jsp page it displays [object Document] in front of my output.
Using a UI dialog I'd like to load in 10 or so images. Each would be unique and after you click on one the following needs to happen:
1. Image appears on the parent page in a specified ID.
2. A "hidden" field is updated so that when the user submits the db is updated with their selection.
3. Dialog closes automatically.
That's it. Basically it would work similar to "datepicker".I'm using the latest 1.4 and ui and been making great progress as learning basics. I need to do the above and it seems like such a no brainier and or it should already exist but after 2 days of searching and trial and error...
I have a string array in a class file that contains 5 values, which I need to display on the jsp page. but when I send it to the javascript it prints [Ljava.lang.String;@104f8b8 .what do i do about it. I am a new to javascript. Is there a way to get my array data from the response object.
I am creating a form using html5 and javascript. Am using <input type = file> tag to browse and display the image file. I need to convert the image file to binary file to store it in web database.
Is there any method to convert image file to binary file.
I am creating a form using html5 and javascript. I need to display user image and am using <input type=file> tag to browse the image file. Now I need to convert the image file to binary file to store it in the web database.
Is there any method in javascript for binary conversion.. convert image file to binary file.
can jQuery display response from .post request in realtime? I force buffer flush in PHP with ob_start, and ob_flush, I know that I can set target='iframeID' to my form, but I need ajax and target should be div.
My requirement: Each time a visitor arrives at a specific webpage i want the main image on the page to be different, or more specifically, one of 6 images which will be shown in rotation. Solution: Set a cookie. Each time the visitor access the page read the cookie and display the corresponding image. Then increment the value and rewrite the cookie, so that next time they'll see the next image in sequence. NB: if the cookie does not exist (first timer) or is at 6, then the value is set to zero (and then incremented).
Problem: Can't get my coding to work. Specifically it just doesn't do anything - no error message, no cookie written. I'm a very novice scripter, as in I've cobbled the coding together from bits off the net that i think i've managed to grasp some kind of an understanding of. Very suck it and see - so far lots of sucking and no seeing!
Actually I need to load another site on my site's onload that means cross domain so after so much googling I got some options something like frames, Iframes and through some tags we can load the responce. So actually I am trying to load gmail in my site so when the user gets logged in then the browser redirecting to full page to Gmail so there I failed at last I am trying to ping with image "img" tag so at backed i am able to see the response is came from the gmail so how can I read that response now.
Im trying to have a click event that replaces an image on the page with a new image that has been selected randomly from an array. I have solved PART of this already (can get the random image to appear).
However, instead of appearing on the page where the old image was, the new image appears in a blank page.
My research indicates that this blank page location-problem is a result of using document.write in the Function. Therefore, I know I need to find a different way to accomplish this, but am failing miserably.
I have been trying for hours and hours and HOURS to figure out proper syntax for accomplishing this via elements, functions, variables and mootools.
A bit of my research:
-I found this---but havent figured out how to implement it in my scenario:
Source: [url]
-I found this---but havent figured out how to implement it in my scenario:
I have an ajax post which returns a large html response. It is getting truncated at 98784 characters everytime. Is there a limit to a response size or a way around this?
We have the following situation - when Ajax request is sent what's being returned by the server is usually an XML (which is used for DOM updates) but sometimes it's HTML which is a whole new page that should replace an existing one. I.e when we issue an Ajax request we don't know what will be returned and analyze the response to act accordingly.
Now, the way to replace the current document with a new one used to be easy and portable for both browsers (we're only supporting IE6 and Firefox 1.5):
document.open(); document.write( head ); document.write( body ); document.close();
where "head" and "body" are two parts of the result HTML. We had to cut it to two (rather than going simply with document.write( NewHTML )) because of IE - our head section contains references to external JavaScript files (<script type="text/javascript" src="sth.js"></script>) and IE only loads them when document.write() call ends. So if body contains any script block (<script type="text/javascript".. </script>) using any of JS referenced by head - IE would fail with something like "Resource undefined" if we push the whole new HTMl in one go by using document.write( NewHTML ). But it worked perfectly fine in Firefox, meaning
did the job just fine. What's even more important - it also evaluated all JavaScripts correctly - both in external files referenced by the head and in the JS blocks embedded in the body.
Until Firefox 1.5.0.6/7 where things stopped working completely - our lovely and used-to-be portable code
document.open(); document.write( head ); document.write( body ); document.close();
caused Firefox to loose all CSS/JS and display an HTML only page (as if CSS/JS were disabled). Removing document.close(); improved the situation a bit by displaying the page with CSS this time but still - *no* JavaScript was evaluated (meaning, JavaScript blocks embedded in the document's body were not evaluated).
I took a different path from this point by pushing the new content to document's head and body "innerHTML". It worked but not for JS evaluation - I had to do that manually. To evaluate the JS referenced in the head section of the document - I've traversed the head's DOM tree while looking for the "script" nodes, then downloaded all of them one by one using a synchronous Ajax calls (don't laugh!) and eval()-ed the response. To evaluate JS blocks embedded in the body of the document - I've traversed the body's DOM tree while looking for the "script" nodes and eval()-ed them.
The problem is following: eval()-ing external JS files after downloading them with Ajax doesn't work in 100% of cases - some statements using Prototype functions fail to execute ("prototype.js" is one of external JS files referenced in the head). Anyway, I'm almost sure that what I'm doing is plain wrong, i.e it's sounds silly to download all JS files referenced in the head and eval() them !
So how do I fix it ? Simply put - how do I replce the content of the document to the completely new one received as a response to asynchronous Ajax call ? The new content conatins doctype, head, body - it's a completely new page. And all JS referenced in the head and embedded in the body should be evaluated as well.
I really wish
document.open(); document.write( head ); document.write( body ); document.close();
was working in Firefox as before. Is it simply a Firefox bug, should I submit it ? Btw, document.open.write.write.close() works just fine in IE6.
I am trying use the Load function and it looks partly succesful:the script code is:
function doCallBack(action, value) { if (action == 'projlokatiemutaties')
[code]....
Projectlokaties1 contains an XML control and the content is being transformed using Xslt. As far as I can see the html variable contains the correct value. However the Response.Write() operations fails completely. As a matter of fact at this point any Response operation fails.
I 'm having an ajax function that polls a server for a response. This response is in fact an html page which is dynamically constructed on the server. What I want is to be a able to replace my current html page ( not only the body ) with the html I am receiving as response from the server. I tried using document.write or innerHTML on html element but none of these does not seem to work. Here is a sample of the code I am using. code..
I have page with an Ajax request which returns an entire <hml>..</html> page and I would like to use this response data to replace the current page. I wrote the following :
I'm having two Ajax-related problems on a page I am working on at the moment. [url] On this page, I have two buttons that use Ajax to fetch two separate forms and put them into a chosen div; that part works like a charm.
On said forms, there is a div that is meant to display any necessary error messages when the submit button is clicked. However, on the first time the page is visited and the form is chosen, the div won't display the error message. Only after refreshing the page/choosing the form a second time will the message show. I've been checking the response from the server via Firebug and the response is correct, it just seems like the page isn't updating correctly.
Secondly, once I refresh or choose the form again and the error message begins to show, if I enter values into the form fields and should be getting a different error message, it never updates. Once again, the server response is correct, but for some reason the page just isn't updating to reflect the new message.
I have been using the date field on the New Event form for testing; if you have Firebug, you should be able to see that I am getting the desired response from the server (look in the allErr div), but the HTML isn't changing with it. I have tried both using my own Ajax functions and using jQuery's Ajax implementation, but both give me the same problems.
A couple of months ago I posted a question in these forums pertaining to some trouble I've been having with a webpage utilizing Javascript and PHP to implement AJAX.
Quote: I'm having two Ajax-related problems on a page I am working on at the moment. (Can't include the link since I'm a new Dev Shed member)
On this page, I have two buttons that use Ajax to fetch two separate forms and put them into a chosen div; that part works like a charm.
On said forms, there is a div that is meant to display any necessary error messages when the submit button is clicked. However, on the first time the page is visited and the form is chosen, the div won't display the error message. Only after refreshing the page/choosing the form a second time will the message show. I've been checking the response from the server via Firebug and the response is correct, it just seems like the page isn't updating correctly.
Secondly, once I refresh or choose the form again and the error message begins to show, if I enter values into the form fields and should be getting a different error message, it never updates. Once again, the server response is correct, but for some reason the page just isn't updating to reflect the new message.
I have been using the date field on the New Event form for testing; if you have Firebug, you should be able to see that I am getting the desired response from the server (look in the allErr div), but the HTML isn't changing with it. I have tried both using my own Ajax functions and using jQuery's Ajax implementation, but both give me the same problems. What am I doing wrong?
I am using a Photo Gallery script called Galleria which uses jQuery/JavaScript to display photos. On my index page load (only in Internet Explorer), a message box pops up saying "Message from Web Page [object Object]". After clicking OK the photo gallery loads and there is no problem.No idea how to fix this, or really what the error means. You can view the error from my site here
I am looking for the best performing solution for modifying and iterating an object graph in JavaScript. I have outlined below a simplified example of the object model and examples of how I will be using this graph.
Object model:
Two objects, [BadApples] and [GoodApples] each contains a collection of [Apple] items (500 max). [Apple] simply has an ID and a name.
Requirements:
A quick way of determining whether a certain apple exists in either [GoodApples] or [BadApples] (by ID).
A quick way of iterating through [GoodApples] and [BadApples] in order to update the web page.
A way of moving a certain [Apple] (by ID) between [GoodApples] and [BadApples].
I currently have this implemented using arrays, but iterating these arrays is expensive. Is there an implementation of a binary-tree for JavaScript? The real-world application may contain many hundreds of nodes, and performance is crucial.