The HTML Layout Control and Internet Explorer 4.0

Updated: September 4, 1997

The HTML Layout Control was released with Internet Explorer 3.0 as an ActiveX™ control to enable two-dimensional layout of content on a Web page. The control used an HTML-like syntax in the form of an ALX file that specified the positioning of various objects within the HTML Layout Control's visible surface.

Internet Explorer 4.0 enables this functionality (and a lot more) natively in the browser without needing an additional ActiveX control. There are a number of minor issues concerning the HTML Layout Control in Internet Explorer 4.0 which require that it no longer be defined as safe for scripting or initialization. It is therefore necessary for users of this control to have security set to low or accept the security warnings when using it in Internet Explorer 4.0.

Because all this functionality is available in Internet Explorer 4.0, sites may wish to convert their content to take advantage of this and the resulting improved efficiency.

About This Transition: Frequently Asked Questions

Why is the HTML Layout Control no longer part of Internet Explorer beginning with Internet Explorer 4.0?

Internet Explorer now natively supports this functionality through the W3C draft proposal for CSS positioning. This means that the same effects can be achieved without loading an ActiveX control because the 2-D positioning support is built into the HTML parsing and rendering engine of Internet Explorer 4.0.

Will my existing HTML Layout Control pages still work in Internet Explorer 4.0?

HTML Layout Control pages should continue to work with Internet Explorer 4.0. However, due to changes in how security is implemented in Internet Explorer 4.0, security must now be set to run unsafe controls . Note that Internet Explorer 4.0's security zones allow this to be done by users/corporations without exposing them to additional dangers. Becuase of this, it is recommended that Web authors move to the native Internet Explorer 4.0 implementation of CSS positioning. Conditional HTML can be used to continue to provide HTML Layout Control support for Internet Explorer 3.x browsers while providing Internet Explorer 4.0 browsers with the native implementation.

How can I migrate my HTML Layout pages so they will work in both Internet Explorer 3.x and 4.0?

The ALX file contains a list of <OBJECT> tags within a <DIV>, so it is simple to convert this syntax to native Internet Explorer 4.0 using the following steps:

Paste the entire contents of the ALX file into the HTML file at the required position.
Remove the "LAYOUT:FIXED" style setting from the <DIV> that wraps the content to the layout control.
For the Style of each OBJECT in the layout control content insert "POSITION:ABSOLUTE".

This should position the content within Internet Explorer 4.0 the same as that of the ALX file, although some adjustment may be necessary. It is also likely that some of the script within the ALX file will need to be adjusted to take into account the object model differences, in particular:

DISPLAY:NONE may change to VISIBILITY:HIDDEN to allow for space to be reserved for the element on the screen.
object.visible = True/False may change to object.style.visibility = "visible"/"hidden" for hotspot usage.

Will autodownloads of HTML Layout Control from Microsoft site still work via <CODEBASE>?

Yes. The HTML Layout Control will continue to be available for download from the Microsoft Object Store and at http://activex.microsoft.com/controls/mspert10.cab to download through the <CODEBASE> tag. Over time we expect the use of this control to diminish as users take advantage of the advanced abilities of Internet Explorer 4.0.

How has support for HTML Layout Control positioning features been enhanced in Internet Explorer 4.0?

The features of the HTML Layout Control are now natively supported in Internet Explorer 4.0 through CSS positioning, which is a working draft with the W3C . The CSS positioning syntax allows for 2-D absolute and relative postioning and z-ordering of all elements within an HTML page, including embedded controls and text, images, and Java applets. In addition, as a native implementation, no separate Internet Explorer component is needed by the user -- all Internet Explorer 4.0 users get this support. Finally, no separate ALX file is needed -- all positioning information can be incorporated directly into the HTML page via CSS.

Will there be new authoring tools that provide support for building pages taking advantage of CSS Positioning?

Yes. Microsoft will be supporting these features in its premier authoring tools, including a future Microsoft FrontPage® and a future release of Microsoft Visual InterDev™. In addition, a variety of third-party software vendors are providing tools to support these features.