AJAX vs. Cookies - Am I just silly?

[dougloj]

Hi.

I have an ASP.NET application written in C#. In part of my
application, I want to use JavaScript OnClick event function to
update a textbox with a string generated asynchronously on the server.
I have pretty much figured out two ways to this. One way involves
AJAX. The other way involves using cookies.

I think AJAX is awesome, but what if the user's browser blocks ActiveX
controls? On the other hand what if the browser blocks cookies? Should
I implement both ways of doing the task, and go the cookies route if
ActiveX controls are blocked?

Any thoughts are welcomed.

Thanks for the bandwidth.

-Doug

 

[Peter Michaux]

Hi.

I have an ASP.NET application written in C#. In part of my
application, I want to use JavaScript OnClick event function to
update a textbox with a string generated asynchronously on the server.
I have pretty much figured out two ways to this. One way involves
AJAX. The other way involves using cookies.

I think AJAX is awesome, but what if the user's browser blocks ActiveX
controls? On the other hand what if the browser blocks cookies? Should
I implement both ways of doing the task, and go the cookies route if
ActiveX controls are blocked?

Any thoughts are welcomed.

I'm curious how cookies can replace an Ajax request. If you can send
the string in a cookie then you know what should be in the textbox
when you serve the page. In that case you don't need either Ajax or
cookies. Just put the string in a JavaScript variable when you
dynamically generate the page.

So what exactly are you trying to do?

Peter

 

[dougloj]

I'm curious how cookies can replace an Ajax request. If you can send

the string in a cookie then you know what should be in the textbox
when you serve the page. In that case you don't need either Ajax or
cookies. Just put the string in a JavaScript variable when you
dynamically generate the page.

So what exactly are you trying to do?

Peter

Peter,

My ASP.NET application submits info to a database. Another application
gets the info from the database and eventually replies by updating the
database. The ASP.NET application the reply and shows the reply to the
user. This all happens asynchronously.

While the users is wainting, a small anamation is displayed. When the
reply is ready, the animation is hidden and the reply is displayed.
The animation and reply are each actually displayed on seperate .aspx
pages that are viewed in the application by an iframe window.

I want the user to be able to print the reply when it arrives.
Unfortunately, my print process won't pick up the contents of the
iframe which contains the reply.

So, when the user clicks the Print button, I want to grab the reply
text, assign it to a lable in an area on the page which will be picked
up by the print process, and print it along with other info on the
page.

As I see it, I have 2 ways of "grabbing" the string. One way is to
write the string to a cookie on the server when it's ready. My
JavaScript code can check for the cookie when the Print button is
clicked. The 2nd way is to write the string to a session variable on
the server when the string is ready, and use AJAX to get the string
when Print is clicked.

Any ideas of a better way, or input on the AJAX vs. Cookie matter are
welcomed.

Thanks.

Doug

 

[Kevin Darling]

While the users is wainting, a small anamation is displayed. When the
reply is ready, the animation is hidden and the reply is displayed.
The animation and reply are each actually displayed on seperate .aspx
pages that are viewed in the application by an iframe window.

I want the user to be able to print the reply when it arrives.
Unfortunately, my print process won't pick up the contents of the
iframe which contains the reply.

Why not pick out the response from the iframe?

Or set the focus to the iframe and then it'll print instead.

Kev

 

[dougloj]

Why not pick out the response from the iframe?

Or set the focus to the iframe and then it'll print instead.

Kev

Kev,

I tried using the innerHTML and innerText of the iframe to get the
response text, but they are empty. Do you know how to get the text
content from an iframe in JavaScript?

As far as the printing goes, I want to print the response text along
with other info on the page. The other info is in a div. Right know, I
write the response text to a cookie on the server when it's ready. My
onClick function for the Print button checks the cookie. If the cookie
exists, I grab the response text, put it in the innerText of a span
within my div, and print the innerText of the whole div.

The JavaScript code for the printing is as follows:

// summaryDiv contains everything that is to be printed,
// including the response span

var summaryDiv = document.getElementById("summaryDiv");

var WinPrint = window.open('','','letf=0,top=0,width=1,
height=1,toolbar=0,scrollbars=0,status=0');

WinPrint.document.write(summaryDiv.innerHTML);
WinPrint.document.close();
WinPrint.focus();
WinPrint.print();
WinPrint.close();

If you or anybody has any ideas about a better way to the print, how
to get the text content of an iframe, or any thoughts on the AJAX vs.
Cookies issue, I'd love to hear from you.

Thanks.

Doug

 

[The Magpie]

I think AJAX is awesome, but what if the user's browser blocks ActiveX
controls? On the other hand what if the browser blocks cookies? Should
I implement both ways of doing the task, and go the cookies route if
ActiveX controls are blocked?

AJAX has nothing whatever to do with ActiveX. So - to answer your
question about it - it is irrelevant if a user blocks ActiveX.
Similarly, AJAX has nothing whatever to do with cookies and the answer
to your second question is also that it is irrelevant.

I have no idea what you mean by "both ways" since AJAX requires
*neither* ActiveX *nor* cookies!

 

[Laurent Bugnion [MVP]]

Hi,

AJAX has nothing whatever to do with ActiveX. So - to answer your
question about it - it is irrelevant if a user blocks ActiveX.
Similarly, AJAX has nothing whatever to do with cookies and the answer
to your second question is also that it is irrelevant.

I have no idea what you mean by "both ways" since AJAX requires
*neither* ActiveX *nor* cookies!

To be fair, XmlHttpRequest in IE6 and older is created using an ActiveX
component.

However, I believe that even if the user blocks ActiveX, the blocking
doesn't affect invisible ActiveX component. I might be wrong though.

Greetings,
Laurent

 

[Randy Webb]

Laurent Bugnion [MVP] said the following on 2/19/2007 4:20 PM:

Hi,



To be fair, XmlHttpRequest in IE6 and older is created using an ActiveX
component.

However, I believe that even if the user blocks ActiveX, the blocking
doesn't affect invisible ActiveX component. I might be wrong though.

If the user blocks ActiveX, then ActiveX is blocked. Meaning, if ActiveX
is blocked then "AJAX" won't work in IE6 and prior IE browsers.

 

[Richard Cornford]

The Magpie wrote:

To be fair, XmlHttpRequest in IE6 and older is created
using an ActiveX component.

However, I believe that even if the user blocks ActiveX,
the blocking doesn't affect invisible ActiveX component.
I might be wrong though.

I don't know what you mean by "invisible ActiveX component". With the
Internet security setting for "Script controls marked safe for scripting"
set to disabled (and/or, I seem to recall, "Run ActiveX controls and
plug-ins" disabled) the ActiveX XML HTTP request component cannot be
instantiated in IE 6.

Microsoft has suffered in the past from more controls being "marked safe
for scripting" than actually were safe. The XML HTTP request object is
not among that group, but the safe option (for the user) is still to
disable that stetting for Internet use. And my money would be on a
security update for IE 6 disabling it by default as soon as Microsoft
think that the take-up of IE 7 is height enough for the loss of XML HTTP
requests in IE 6 not to seem important to .NET customers.

Richard.

 

[Laurent Bugnion [MVP]]

Hi Randy,

Laurent Bugnion [MVP] said the following on 2/19/2007 4:20 PM:

If the user blocks ActiveX, then ActiveX is blocked. Meaning, if ActiveX
is blocked then "AJAX" won't work in IE6 and prior IE browsers.

Thanks for the correction. I got to try that, I must have an old IE6
running somewhere...

Greetings,
Laurent