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Monday, December 3, 2007
Earth and Moon Viewer, Your Sky, and Solar System Live Updated
I have just posted updated versions of Earth and Moon Viewer, Your Sky, and Solar System Live which improve usability by wrapping applicable radio button and checkbox controls in XHTML “<label>” containers. This is an often-neglected refinement which makes a page both kinder to visitors and more professional in appearance. When you're creating an XHTML form with controls of these types, if you simply include the controls with adjacent labels, the user has to click on the button itself (which in these cases is rather small), but if you enclose the control and its legend within a “<label>” container (or, equivalently, tie the legend to the control with the “<label for="id">” form of the tag), then the user can click anywhere in the legend as well as on the control itself. This not only provides a larger target, it's consistent with the behaviour of most window systems with which users are familiar. For example, consider the following do-nothing form:Note that you can click on either the button or the legend of “Gromify”, which is enclosed in a “<label>” container, but only on the button for “Brozzulate”, which is not. The weasel word “applicable” in the first sentence excludes legends of buttons which are already links to a help file item explaining the button. Obviously, a legend can only do one thing when you click it, and I decided that preserving help file links was more important than the convenience of pressing the button by clicking the legend. The ability to click on legends has been extended not only to dynamic pages returned by the applications, but to all associated static pages (custom request forms, help text, etc.). A few additional changes were made in Your Sky:
- In the Ephemeris tables, the abbreviations “AU” (astronomical unit) and “ER” (Earth radius) now pop up a definition of the term if you move the mouse over them.
- A typographical error in the URL used to embed the image in results from the Horizon View and Virtual Telescope applications caused a validation error with the most recent version of the W3C Markup Validation Service—fixed.
- All signed numbers appearing in XHTML now use the “−” text entity instead of the ASCII “-” which most browsers render as a hyphen instead of a minus sign as wide as the plus sign.