parsing complex user inputs

S

Sven Neuberg

Hi,

I have been handed the task of updating and maintaining a web
application, written in ASP and Javascript, that takes complex
user inputs in HTML form and submits them to server-side ASP
pages for processing. The problem is, the user inputs can
become very complex, and the way this application was developed,
the inputs are all concatenated into monstrously long strings
of text that are then submited as <hidden> inputs in HTML forms
and parsed by the server-side ASP. This results in hideous strings
that go on and on like
johnsmith~1232^01^Yes^no~~|43|april

etc. etc. This code is an incredible pain to maintain and update.
There has got to be a better way to do this. I am required to
use javascript and vbscript in ASP pages on the client side,
and ASP pages for processing data on the server side. I can't
switch to a different technology, or use .NET, or anything like
that. I have to use JS and VBScript to get intricate and lengthy
user inputs and submit them for processing. I would like to
store these inputs in objects somehow and then get the data
from those objects, if possible.

If anyone could suggest a better method for doing all of this
in javascript, even just to point me in the right direction, I would
greatly appreciate it.

sven
 
M

McKirahan

Sven Neuberg said:
Hi,

I have been handed the task of updating and maintaining a web
application, written in ASP and Javascript, that takes complex
user inputs in HTML form and submits them to server-side ASP
pages for processing. The problem is, the user inputs can
become very complex, and the way this application was developed,
the inputs are all concatenated into monstrously long strings
of text that are then submited as <hidden> inputs in HTML forms
and parsed by the server-side ASP. This results in hideous strings
that go on and on like
johnsmith~1232^01^Yes^no~~|43|april

etc. etc. This code is an incredible pain to maintain and update.
There has got to be a better way to do this. I am required to
use javascript and vbscript in ASP pages on the client side,
and ASP pages for processing data on the server side. I can't
switch to a different technology, or use .NET, or anything like
that. I have to use JS and VBScript to get intricate and lengthy
user inputs and submit them for processing. I would like to
store these inputs in objects somehow and then get the data
from those objects, if possible.

If anyone could suggest a better method for doing all of this
in javascript, even just to point me in the right direction, I would
greatly appreciate it.

sven

It sounds like the user fills in numerous fields and, on form submission,
the data is concatenated into a single (hidden) field for passing to the
server where it is parsed (perhaps using "Split()"), validated, and
processed.

One option is remove the concatenation+parsing and just refer to each file
via "Request.Form("fieldname") on the server.

Is any validation done on the client-side?

Is any manipulation done on the client-side?
 
G

Grant Wagner

Sven said:
Hi,

I have been handed the task of updating and maintaining a web
application, written in ASP and Javascript, that takes complex
user inputs in HTML form and submits them to server-side ASP
pages for processing. The problem is, the user inputs can
become very complex, and the way this application was developed,
the inputs are all concatenated into monstrously long strings
of text that are then submited as <hidden> inputs in HTML forms
and parsed by the server-side ASP. This results in hideous strings
that go on and on like
johnsmith~1232^01^Yes^no~~|43|april

etc. etc. This code is an incredible pain to maintain and update.
There has got to be a better way to do this. I am required to
use javascript and vbscript in ASP pages on the client side,
and ASP pages for processing data on the server side. I can't
switch to a different technology, or use .NET, or anything like
that. I have to use JS and VBScript to get intricate and lengthy
user inputs and submit them for processing. I would like to
store these inputs in objects somehow and then get the data
from those objects, if possible.

Everyone would like to be able to serialize client-side JavaScript
objects and send them to the server, unfortunately HTTP doesn't work
that way. To get the data to the server, you have to make an HTTP
request (usually GET or POST). The only thing you can send to the server
with a GET or POST are HTTP headers (which client-side JavaScript has no
access to without using the XML HTTP Request object) and the URL itself.

So at some point, you need to turn your complex data structure into
delimited text, or text attached to multiple attributes, or something,
to get it to the server.

The XML HTTP Request object does not change this, except it gives you
the ability to send custom HTTP headers and POST data without a said:
If anyone could suggest a better method for doing all of this
in javascript, even just to point me in the right direction, I would
greatly appreciate it.

If you are trying to move complex client-side data structures to the
server, the only way to do it is to "serialize" it by doing what the
previous author of the site you must maintain has done, and then
reconstruct the data structure on the server from the "serialized" data
(delimited strings).
 
J

Jamie Jackson

Sven Neuberg wrote:

Everyone would like to be able to serialize client-side JavaScript
objects and send them to the server, unfortunately HTTP doesn't work
that way. To get the data to the server, you have to make an HTTP
request (usually GET or POST). The only thing you can send to the server
with a GET or POST are HTTP headers (which client-side JavaScript has no
access to without using the XML HTTP Request object) and the URL itself.

What about using WDDX to ease the parsing woes?

Jamie
 
S

Sven Neuberg

McKirahan said:
It sounds like the user fills in numerous fields and, on form submission,
the data is concatenated into a single (hidden) field for passing to the
server where it is parsed (perhaps using "Split()"), validated, and
processed.

Yes, and not only that, there could be a dozen "sets" of this information,
all in one very long hidden field.

One option is remove the concatenation+parsing and just refer to each file
via "Request.Form("fieldname") on the server.

I'm not sure what you mean, sorry.

Is any validation done on the client-side?

Yes, quite a bit.

Is any manipulation done on the client-side?

Yes, because the user may choose to go back and edit some of the
fields, so there is quite a bit of parsing of the strings going on.

thank you,

sven
 
J

Joakim Braun

Sven Neuberg said:
Hi,

I have been handed the task of updating and maintaining a web
application, written in ASP and Javascript, that takes complex
user inputs in HTML form and submits them to server-side ASP
pages for processing. The problem is, the user inputs can
become very complex, and the way this application was developed,
the inputs are all concatenated into monstrously long strings
of text that are then submited as <hidden> inputs in HTML forms
and parsed by the server-side ASP. This results in hideous strings
that go on and on like
johnsmith~1232^01^Yes^no~~|43|april

<snip>

What happens if a user inputs one of the delimiting characters ("Joh|n
Smi~th")?

That problem is solved if you write Javascript to serialize/unserialize
arrays, and the same code in your server-side language.

For instance, say you collect form values into an array like:
var theThing = new Array("johnsmith", "Yes", 1232);

You could convert this into something like:
Array{key sz:1{0} string sz:9{johnsmith} key sz:1{1} string sz:3{Yes} key
sz:1{2} int sz:4{1232}}

You post it to the server, which reconstitutes the array. This would work
regardless of the input values and it's a bit easier to maintain.

Joakim Braun
 
G

Grant Wagner

Joakim said:
<snip>

What happens if a user inputs one of the delimiting characters ("Joh|n
Smi~th")?

That problem is solved if you write Javascript to serialize/unserialize
arrays, and the same code in your server-side language.

For instance, say you collect form values into an array like:
var theThing = new Array("johnsmith", "Yes", 1232);

You could convert this into something like:
Array{key sz:1{0} string sz:9{johnsmith} key sz:1{1} string sz:3{Yes} key
sz:1{2} int sz:4{1232}}

You post it to the server, which reconstitutes the array. This would work
regardless of the input values and it's a bit easier to maintain.

Joakim Braun

One last note about this, the Object#toSource() method is well-suited to the
task of serializing your object. Try the following code in any Gecko-based
browser (Firefox, Mozilla, Netscape 7+):

var o = new Object();
o.a = 1;
o.b = '2';
o.c = new Object();
o.c.d = 3;
o.c.e = '4';
alert(o.toSource());

Unfortunately, toSource() isn't supported in IE. :(
 
S

Sven Neuberg

Joakim Braun said:
For instance, say you collect form values into an array like:
var theThing = new Array("johnsmith", "Yes", 1232);

You could convert this into something like:
Array{key sz:1{0} string sz:9{johnsmith} key sz:1{1} string sz:3{Yes} key
sz:1{2} int sz:4{1232}}

You post it to the server, which reconstitutes the array. This would work
regardless of the input values and it's a bit easier to maintain.


Thank you! I am going to look into this. It looks like it could be very
helpful.

sven
 
S

Sven Neuberg

Grant Wagner said:
Unfortunately, toSource() isn't supported in IE. :(

Unfortunately, IE is our target browser, and it is a decision that is
out of my control. :(

sven
 
J

Joakim Braun

Sven Neuberg said:
Thank you! I am going to look into this. It looks like it could be very
helpful.

Below is my own code which works for my needs. It turns arrays (which may
contain other arrays as well as strings, booleans and numbers) into strings
and back. Array keys are preserved. There are probably better/more
efficient/more compact ways to do this. Note that strings are escaped,
you'll have to unescape them server-side.

Joakim Braun

***

function serializeArray(inArray){

var theResult = "";
var arrayConstructor = new Array().constructor.toString();
var thing = true;

for(var i in inArray){

var theType = typeof(inArray);
var key = escape(i.toString());

theResult += "key sz:" + key.length + "{" + key + "}";

if(inArray && inArray.constructor &&
inArray.constructor.toString() == arrayConstructor){

var arrData = serializeArray(inArray);
theResult += "Array sz:" + arrData.length + "{" + arrData + "}";

}
else{
var str = escape(inArray.toString());
theResult += theType + " sz:" + str.length + "{" + str + "}";
}
}
return theResult;

}


function unserializeArray(inString){

var theResult = new Array();
var theKey = "";

// Note that arrays with zero entries will come in as "Array sz:0{}".
// The recursion will then be called with "zero string",
// which is why we check for inString.length
while(true && inString.length > 0){

var nextLeftBracketIndex = inString.indexOf("{", 0);
var theType = inString.substr(0, inString.indexOf(" ", 0));
var sizeOffset = inString.indexOf("sz:", 0) + 3;
var dataSize = parseInt(inString.substr(sizeOffset, nextLeftBracketIndex -
sizeOffset));
var theData = inString.substr(nextLeftBracketIndex + 1, dataSize);

// This will save legacy arrays
if(theKey == "")
theKey = theResult.length;

if(theType == "key"){

if(!isNaN(theData)){
theKey = parseInt(theData);
}
else if(theData.length > 0){
theKey = unescape(theData);
}
}
else if(theType == "number"){

theResult[theKey] = parseFloat(theData);
theKey = "";
}
else if(theType == "string"){

theResult[theKey] = unescape(theData);
theKey = "";
}
else if(theType == "boolean" ){

var val = new Boolean(theData);
theResult[theKey] = val == true ? true : false;
theKey = "";
}
else if(theType == "Array"){

// Recurse
theResult[theKey] = unserializeArray(theData);
theKey = "";
}
else{

prompt("Unknown object: " + theType + "\ninString: " + inString,
inString);
}

nextLeftBracketIndex = nextLeftBracketIndex + 2 + dataSize;

if(inString.length - nextLeftBracketIndex > 0){
inString = inString.substr(nextLeftBracketIndex, inString.length -
nextLeftBracketIndex);
}
else
break;
}

return theResult;

}
 
J

Jamie Jackson

I have never heard of it, but now I am looking at www.openwddx.org to
see if it will help. Thank you for the suggestion.

When I look at that site, it's not immediately apparent what it's all
about.

Here's what I understand WDDX to be:
Each language has a couple of API functions (already) written for it:
Something like JSToWDDX and WDDXToJS for JavasScript and maybe
VBToWDDX and WDDXToVB for VB. It allows for easy serialization and
de-serialization of variables. Behind the scenes WDDX is a particular
type of XML, but you aren't exposed to those complexities, since you
use the simple API methods to create/consume the WDDX.

I'm no expert, so apologies if you find that I'm incorrect. I have,
however, used WDDX to serialize and de-serialize ColdFusion objects
within ColdFusion. I just have never taken advantage of the main
benefit -- cross-language, complex variable communication.

Thanks,
Jamie
 

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