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Web Development Forum (continued)

By MaryWeilage Editor ·
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XMLHttpRequest object in Mozilla-based browsers

by MaryWeilage Editor In reply to Web Development Forum (co ...

The Sept. 2 edition of the Web Development Zone e-newsletter explains and demonstrates how you can use the XMLHttpRequest object in Mozilla-based browsers. If you're interested in learning more about several of the topics mentioned in the newsletter, please visit the following links.

For more information about XBL:

For more information about using XML data islands in Mozilla:

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Using XmlHttpRequest to upload [binary] files

by vkelman In reply to XMLHttpRequest object in ...


I'm trying to write [JavaScript] code to upload [binary] files from user's machine to a server (PHP page) using XmlHttpRequest object.

The very first question is how to attach a file to XmlHttpRequest? As I understand I need to create something called a "stream" to do it. Is it possible to do it in Mozilla and IE using JavaScript and possible XML?

Vladimir Kelman

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More precise

by vkelman In reply to Using XmlHttpRequest to u ...

More precise: I was going to use such a technique in my photo gallery to allow authors to upload their pictures. I don't want to limit their browsers to IE only and their OS to W2K. I'm successfully using XmLHttpRequest object on both IE and Mozilla to post data without page reloading, but it looks like it is not possible to use it for file uploading and I hav eto revert to IFRAME technique....

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Re: Don't let cookies' security crumble

by ak_from_ak In reply to Web Development Forum (co ...

"John McCormick is a security consultant and well-known author in the field of IT, with over **15,500** published articles."

Hehehe, must be a busy boy, that works out to something like an article every day for over 42 years.... When does he have time for consulting???? :)

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Managing layout with custom elements

by MaryWeilage Editor In reply to Web Development Forum (co ...

This week's Web Development Zone e-newsletter discusses how to manage layouts with custom elements. How do you maintain consistent layouts from page to page? Do you think you'll use the method described in the column to do so in the future? Please share your thoughts on this subject.

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Creating a WML phone directory

by MaryWeilage Editor In reply to Web Development Forum (co ...

The Oct. 21 and Oct. 28 Web Development Zone e-newsletter describes how to create a Wireless Markup Language (WML) phone directory. What are your experiences with WML? Do you think you'll create a WML phone directory using the example in this e-newsletter?

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Uploading files with XMLHTTP - Questions

by ChuckR314159 In reply to Web Development Forum (co ...

I have a couple questions related to Philip Perkins 7/16 Web Development Zone article.

We've been looking for an easy way to allow file uploads to our server. We can handle the login/permissions okay, but if we used this method...

(1) With respect to the two objects declared in the javascript (ADODB.Stream and MSXML2.XMLHTTP)...Do we need to worry about something being installed on the client machine for this to work, or do these typically exist as part of all mainstream browsers, OS's, or something else?

(2) We've tried some other freeware routines that we've downloaded that seem to have a severe file size limitation and I've seen references to inherent size limitations in some methods. Does this method have a similar limitation?

(3) What about virus protection? Is there a way to programmatically invoke a virus scan of a file before it gets uploaded to the server, or are there other precautions we can take?

(4) Can anyone suggest a way to get "progress" info back to the browser so that we can present a "progress bar" or some such visual for large file uploads?

Thanks in advance,

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Response from author Phillip Perkins

by MaryWeilage Editor In reply to Uploading files with XMLH ...

(1) ADODB.Stream is included with Microsoft Data Access Components (MDAC) 2.6 or above. This should be available on machines running Windows 2000 or above and I think it's part of the latest service pack for NT. However, I'm not very sure about anything below Windows 2000. You can get it as a download. The problem is that in order to utilize this component, you must either have "Initialize and script ActiveX controls not marked as safe" set to Prompt or Enable in IE's security. MSXML2.XMLHTTP is only available in XML 2.6 or above. This is a safe object so you can script it in IE without any problems. There is another XMLHTTP object you can script for older versions of XML: Microsoft.XMLHTTP. The later version is available to IE 5.5 SP2 browsers and above. The earlier version is available to IE 5.0 browsers. In order to overcome either situation try this:
var xmlhttp = null;
function window_onload() {
try {
xmlhttp = new ActiveXObject("MSXML2.XMLHTTP");
} catch(e) {
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
} finally {
alert("This functionality is limited to IE 5.0 and above.");

(2) I tested it on a 91MB file and it failed. I think there is an inherent POST size limitation with IIS, but I'm not sure. I read somewhere that there isn't one, but that doesn't explain why it doesn't work. I can try to find out more if you like.

(3) You can scan the virus once it's been uploaded. As long as there isn't any kind of automatic execution of a file, it should be safe but I'm not promising anything.

(4) I don't know if there is any way to put a progress bar on this, but I haven't tried.

The best advice that I have for you is to develop an internet component, implement the IObjectSafety interface (allows for scripting without prompt or disable), and digitally sign it so it can be installed on the user's system. You would then use either the MS Internet Transfer Control or the MS Winsock control to send the file data to the remote server. That way, you can provide a progress bar as well. If you need more information on this, just let me know:

Phillip Perkins

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Universal data management and services through raw HTML

by MaryWeilage Editor In reply to Web Development Forum (co ...

In the November 4 and November 11 Web Development Zone e-newsletters, Phillip Perkins explores universal data management and services through raw HTML. Do you agree with Phillip Perkins' statement that the way to truly ensure that all browsers can see your Web site is to provide only raw HTML to the browser? What design concept makes your development easier? What techniques do you use to manage user navigation and produce alternative techniques for saving/transferring data? Share your thoughts in this discussion forum.

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KISS is the key!

by dkhorne In reply to Universal data management ...

Having been burnt in one development by inconsistent support for CSS, I have come to the conclusion that Keeping It Simple (Stupid) is the key to wide support development.

I recently used this principle to create an online irdering system that went into production with virtually no major issues. So I applaud the approach outlined in this article and look forward to Part 2

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