EasyForm is a tiny classic-ASP library made up of two ASP files and less than 300 lines of code. Use it if you want:
- Automatic keeping of HTML controls state
- An easy way to set and get the control's values, attributes and additional data
- Server-side event handling
ASP.NET technology takes advantage of the hundreds of classes in .NET Framework. Its power cannot be compared to the good old ASP, so it doesn't make sense trying to emulate its many features using the beloved ancestor. Even if that were possible, we would get a new complex framework. Such a work would be a waste of time: who would spend time learning to use a non-standard clone where there is the original? Nevertheless, classic ASP applications still exist and need maintenance, and others will be created. My purpose was to implement something that speeded up some work involved in creating ASP forms. It had to be easy to learn, easy to use, lightweight and able to work on hosting environments with restricted privileges (that is not allowing self-made COM objects).
Using the Code
First of all, my suggestion is to download and run the examples. The sample code is really simple to understand.
Two Minutes Recipe
Copy EasyForm.asp and Encryption.asp in any directory of your Web application.
Make a form page using a structure similar to the following:
if EF.IsFirstLoad then
email.value = "type your email"
role.value = "noselection"
response.write "user email = " & email.value
response.write "<br>user role = " & role.value
<input type="text" <%email.Bind%> />
<option <%role.addoption "noselection"%>>Select role...</option>
<option <%role.addoption "cs"%>>C# developer</option>
<option <%role.addoption "cpp"%>>C++ developer</option>
<option <%role.addoption "web"%>>Web developer</option>
<input type=button value="Save" <%button1.Bind %> />
- Include EasyForm.asp in your form page.
EF.DimVar to declare the
EasyForm variables and their control type.
- Call the
- Define the
EF_onLoad sub and write the initialization code.
- Attach each HTML control to an
EasyForm variable using the
AddOption methods of the variable. Don't specify the
value attributes for controls other than buttons. When you attach an
button" variable to a button control, you must define a handler for the click event of that
Sample2 show how to attach each type of HTML control to an
EF.EndForm before the enclosing tag of the form.
Tell Me More
The EasyForm.asp file defines the two classes
EFVariable, then it creates an instance of
EasyForm class called
EF, ready to be used in your pages.
This file is included in EasyForm.asp. Here we have the functions
EF_Decrypt, used internally to perform a trivial cryptography of data stored in hidden fields. Replace them if you need.
EF object is an instance of the
EasyForm class created automatically when you include EasyForm.asp file.
EF.DimVar VarName, ControlType
string that specifies the name of the variable
string that specifies the type of HTML control to which the variable will be attached.
Possible values are "
textarea", " ,"
EasyForm variables are instances of class
EFVariable. You must create them using
EF.DimVar method. On creation, each variable reads its value from posted data, if any, matching the name you declared for it through
EF.DimVar. Otherwise defaults to an empty
string or to the value you assign it in
After it is declared, the
EasyForm variable name exists at global scope. You will use it as any other object variable.
If you declare a "
button" variable named
MyButton and you attach it to a button control, then you must define a handler named
MyButton_OnClick for the click event of that button. In more complex situations, you may use the
The "generic" type allows you to attach an
EasyForm variable to a generic HTML element. This is useful to attach data to the element or to set its attributes in server-side code.
Literals are special
EasyForm variables that do not need to be attached to a control or element. Literals are similar to classic variables, but they are able to remember their value in subsequent form postbacks, using encrypted hidden fields.
You must call it after
EasyForm variables declaration. This method calls the
EF_onLoad sub and, if an event is fired, the related handler. If you need to use some global variables inside
EF_onLoad or other handlers, declare and initialize such variables before calling
You must call it. This method adds some hidden fields and the
Boolean readonly property. Its value is
true if the page is loaded for the first time.
You must define this sub, even if it may be empty. The initialization code for the
EasyForm variables should be placed here. This sub is called each time the page is loaded and you may use
EF.IsFirstLoad property to distinguish between a first load and a postback. This is important to prevent your initialization code from overwriting the user inputs after a postback. You
set the value of an
EasyForm variable using its
EasyForm variable is an instance of the
EFVariable class. Its properties and methods make it easy to work with HTML controls. When you attach an
EFVariable to an HTML control, you don't have to take care of keeping the control state in subsequent postbacks. The
EFVariable does it for you. You must declare an
Value property allows you to
string value of the variable. Depending on the type of HTML control to which the variable is attached, such a value will be rendered in the right way.
Bind method attaches the variable to a control. You must call the
Bind method in the HTML tag of the control. This method injects in the control HTML the variable name as the name attribute of the control. Also, based on
controltype, it writes the HTML necessary to set the current value of the control. If you set some attributes using the
Attributes property of the variable, then the
Bind method injects the couples (
AttributeValue) in the control. For
<option> tag, use
<select> tag still needs a call to
Bind. See Sample1 and Sample2.
It's similar to
Bind method and must be used with
<option> elements and
<input type=radio>. See Sample1 and Sample2.
Attributes Collection Property
object.Attributes(AttributeName) = AttributeValue
StringVar = object.Attributes(AttributeName)
string value of an attribute. When calling
Bind method, the assignments
AttributeName="AttributeValue" are written in the HTML for each attribute in the collection. If the attribute value is boolean and is
true, then the only attribute name is written (example:
disabled). The collection is stateful, and is stored in an encrypted hidden field. This means that if you set any attributes, you don't need to set them again in subsequent postbacks. See Sample3 and Sample4.
Data Collection Property
object.Data(DataName) = DataValue
StringVar = object.Data(DataName)
string value for custom data. Unlike attributes, custom data are not automatically written in HTML. The collection is stateful, and is stored in an encrypted hidden field.
In case of
radio controls, the data names can be indexed using the values of the options as indexes. You can get the data value corresponding to the selected option of the control using the
object.Data(DataName[optionValue]) = DataValue
StringVar = object.Data(DataName[value])
EF_Call ( ServerSideSub [, Argument])
Called on client side, executes the server side sub specified in
ServerSideSub parameter. If you specify an
Argument then the sub must take a parameter. Calling
EF_Call with an empty
string performs a submit without calling any sub. See Sample3 and Sample4.
- 27th November, 2008: Initial post