JavaScript 2.0-The Complete Reference, Second ... - freecodingtutorial

name="myform">> no matter where it occurs in a document. The main properties of an
individual Form (or under the DOM HTMLFormElement) object are related to the attributes of
the tag and include
action The URL to submit the form to as specified by the action attribute. If
unspecified, the form will submit to the current document location.
encoding The value of the enctype attribute, generally application/x-www-formurlencoded
unless using a file upload when it should be multipart/form-data.
Occasionally, value may be text/plain when using a mailto: URL submission.
encType The DOM property to be used in place of the traditional encoding property to
access the enctype attribute‘s value.
method The method attribute value, either get or post. The get method is the default
when unspecified.
name The name of the form if defined.
target The window or frame name to display the form result within.
The Form object also specifies a length property that corresponds to the number of fields within
the form defined by , , , and possibly in
browsers that support this HTML element. Object references to these elements are stored in
the elements[] collection of the Form object to be discussed next. Last, the Form object
supports two methods, submit() and reset(), which correspond to the submission and resetting
of the form.
Form Elements Collection
The elements[] collection for each Form object is an array containing the various fields in a
form including checkboxes, radio buttons, select menus, text areas, text fields, password fields,
Reset buttons, Submit buttons, generic buttons, and even hidden fields. Later JavaScript
implementations also support file upload fields. Access to form elements can be performed
numerically (document.myform.elements[0]) or by name (document.myform.textfield1).
The number of elements in the form is accessible either with document.formname.length or
document.formname.elements.length. The properties of each form field object vary based
upon the HTML syntax. Let‘s look at the standard text field to get the idea.
A text field in (X)HTML is defined by , so
accordingly you would expect the properties for a text field object to be type, name, size,
maxlength, and value. In the case of the DOM standard, we see that the maxlength attribute
should be referenced as maxLength. Also defined is the property defaultValue, which holds
the original value, specified by the value attribute since the value property of this object will
change as the user changes the field. A simple example showing the manipulation of a text field
is shown here.
Text Field Fun