IFRAME - Inline Frame

Syntax

<IFRAME>...</IFRAME>

Attribute Specifications

SRC=url (url of frame content)
NAME=CDATA (name of frame)
LONGDESC=url (link to long description)
WIDTH=Length (frame width)
HEIGHT=Length (frame height)
ALIGN=[ top | middle | bottom | left | right ] (frame alignment)
FRAMEBORDER=[ 1 | 0 ] (frame border)
MARGINWIDTH=Pixels (margin width)
MARGINHEIGHT=Pixels (margin height)
SCROLLING=[ yes | no | auto ] (ability to scroll)
[4.0] ID=string
[4.0] CLASS=string
[4.0] STYLE=string
[4.0] TITLE=string

Contents

Inline elements, block-level elements

Contained in

Inline elements, block-level elements

Description

The IFRAME element defines an inline frame for the inclusion of external objects including other HTML documents. IFRAME provides a subset of the functionality of OBJECT; the only advantage to IFRAME is that an inline frame can act as a target for other links. OBJECT is more widely supported than IFRAME, and, unlike IFRAME, OBJECT is included in HTML 4.0 Strict.

SRC & NAME

IFRAME's SRC attribute provides the location of the frame content--typically an HTML document. The optional NAME attribute specifies the name of the inline frame, allowing links to target the frame.

The content of the IFRAME element is used as an alternative for browsers that are not configured to show or do not support inline frames. The content may consist of inline or block-level elements, though any block-level elements must be allowed inside the containing element of IFRAME. For example, an IFRAME within an H1 cannot contain an H2, but an IFRAME within a DIV can contain any block-level elements.

LONGDESC

The LONGDESC attribute gives the url of a long description of the frame's contents. This is particularly useful for full descriptions of embedded objects. Note that LONGDESC describes the frame content while the content of the IFRAME element acts as a replacement when the external resource cannot be inlined.

An example follows:

<IFRAME SRC="recipe.html" TITLE="The Famous Recipe">
<!-- Alternate content for non-supporting browsers -->
<H2>The Famous Recipe</H2>
<H3>Ingredients</H3>
...
</IFRAME>

WIDTH, HEIGHT & FRAMEBORDER

The WIDTH and HEIGHT attributes specify the dimensions of the inline frame in pixels or as a percentage of the available space. The FRAMEBORDER attribute specifies whether or not a border should be drawn. The default value of 1 results in a border while a value of 0 suppresses the border. Style sheets allow greater flexibility in suggesting the border presentation.

ALIGN

The ALIGN attribute specifies the alignment of the inline frame. The values top, middle, and bottom specify the frame's position with respect to surrounding content on its left and right.

ALIGN=middle aligns the center of the frame with the current baseline. To center the frame horizontally on the page, place the frame in a centered block, e.g.,

<P ALIGN=center><IFRAME SRC="foo.html" WIDTH=300 HEIGHT=100></IFRAME></P>

The other ALIGN values, left and right, specify a floating frame; the frame is placed at the left or right margin and content flows around it. To place content below the frame, use <BR CLEAR=left|right|all> as appropriate.

The vertical-align and float properties of Cascading Style Sheets provide more flexible methods of aligning inline frames.

MARGINWIDTH & MARGINHEIGHT

The MARGINWIDTH and MARGINHEIGHT attributes define the number of pixels to use as the left/right margins and top/bottom margins, respectively, within the inline frame. The value must be greater than one pixel.

SCROLLING

The SCROLLING attribute specifies whether scrollbars are provided for the inline frame. The default value, auto, generates scrollbars only when necessary. The value yes gives scrollbars at all times, and the value no suppresses scrollbars--even when they are needed to see all the content. The value no should never be used.

[4.0] ID

The ID attribute uniquely identifies an element within a document. No two elements can have the same ID value in a single document. The attribute's value must begin with a letter in the range A-Z or a-z and may be followed by letters (A-Za-z), digits (0-9), hyphens ("-"), underscores ("_"), colons (":"), and periods (".").

The following example uses the ID attribute to identify each of the first two paragraphs of a document:

<P ID=firstp>My first paragraph.</P>
<P ID=second>My second paragaph.</P>

The paragraphs in the example could have style rules associated with them through their ID attributes. The following Cascading Style Sheet defines unique colors for the two paragraphs:

P#firstp {
  color: navy;
  background: transparent
}

P#secondp {
  color: black;
  background: transparent
}

The paragraphs in the initial example could also be used as a target anchor for links:

<P>See <A HREF="#firstp">the opening paragraph</A> for more information.</P>

Note that most browsers do not support the ID attribute for link anchors. For current browsers, authors should use <A NAME>...</A> within the element instead of ID.

Since ID and NAME share the same name space, authors cannot use the same value for an ID attribute and a NAME attribute in the same document. Also note that while NAME may contain entities, the ID attribute value may not.

[4.0] CLASS

The CLASS attribute specifies the element to be a member of one or more classes. Classes allow authors to define specific kinds of a given element. For example, an author could use <CODE CLASS=Java> when giving Java code and <CODE CLASS=Perl> when giving Perl code.

Unlike with the ID attribute, any number of elements can share the same class. An element may also belong to multiple classes; the CLASS attribute value is a space-separated list of class names.

Note that most current browsers do not support multiple classes. Such browsers typically ignore a CLASS attribute that specifies multiple classes.

The CLASS attribute is particularly useful when combined with style sheets. For example, consider the following navigation bar:

<DIV CLASS=navbar>
<P><A HREF="/">Home</A> | <A HREF="./">Index</A> | <A HREF="/search.html">Search</A></P>
<P><A HREF="/"><IMG SRC="logo.gif" ALT="" TITLE="WDG Logo"></A></P>
</DIV>

This example's use of the CLASS attribute allows style rules to easily be added. The following Cascading Style Sheet suggests a presentation for the preceding example:

.navbar {
  margin-top: 2em;
  padding-top: 1em;
  border-top: solid thin navy
}

.navbar IMG { float: right }

@media print {
  .navbar { display: none }
}
[4.0] STYLE

The STYLE attribute allows authors to specify style rules inline for a single occurrence of an element. An example follows:

<P>A popular font for on-screen reading is <SPAN STYLE="font-family: Verdana">Verdana</SPAN>.</P>

When the STYLE attribute is used, a default style sheet language must be specified for the document by setting the Content-Style-Type HTTP header to the media type of the style sheet language. The previous example could use the following META element in the document's HEAD:

<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css">

In most cases, use of the CLASS or ID attributes is a better choice than using STYLE since ID and CLASS can be selectively applied to different media and since they provide a separation of content and presentation that often simplifies maintenance.

[4.0] TITLE

The TITLE attribute provides a title for an element and is commonly implemented as a "tooltip" on visual browsers, though many browsers lack support for TITLE. The attribute is most useful with A, LINK, IMG, and OBJECT elements, where it provides a title for the linked or embedded resource. Some examples follow:

TITLE is also helpful with the ABBR and ACRONYM elements to provide the long form of the abbreviation. Examples:

More Information

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