CodeHelp - glossary D

• Constructors
  Create a new date object with current time and date pre-set:
  var mydate = new Date();
  
  Create a new date object from the number of milliseconds since the epoch (1st Jan 1970 = 0 so setting a remotely recent date this way leads to some very large numbers):
  var mydate = new Date(987654321987);
  
  Create a new date object from a "DateString". The easiest way to create a datestring is by using one of the other constructors for Date and use one of the toXXXString methods to output the datestring.
  var mydate = new Date("Sat Mar 23 10:02:24 UTC 2002");
  
  Create a new date object using specified year, month (counting from January = zero), day, hours, minutes, seconds and milliseconds.
  var mydate = new Date(2002, 0, 22, 9, 14, 30, 0);
• Properties
  The Date object has no public properties, all access to data within a Date object must be by using Methods.
• Methods
  Return the current day of the month (numerical):
  var mthday = mydate.getDate(); Universal Time: mydate.getUTCDate();
  Set the day of the month for this Date object:
  mydate.setDate(mthday); mydate.setUTCDate(mthday);
  
  Return the current day of the week (numerical, Sunday=0):
  var wkday = mydate.getDay();
  Universal Time: mydate.getUTCDay();
  Set the day of the week for this Date:
  mydate.setDay(wkday);
  
  Return the current year (numerical):
  var fyear = mydate.getFullYear();
  Universal Time: mydate.getUTCFullYear();
  Set the year for this Date:
  mydate.setFullYear(fyear); mydate.setUTCFullYear(fyear);
  
  Return the "hours" field of a Date (numerical):
  var hours = mydate.getHours();
  Universal Time: mydate.getUTCHours();
  Set the hours field:
  mydate.setHours(hours); mydate.setUTCHours(hours);
  
  Return the "milliseconds" field of a Date (numerical):
  var msec = mydate.getMilliseconds();
  Universal Time: mydate.getUTCMilliseconds();
  Set the milliseconds field
  mydate.setMilliseconds(msec); mydate.setUTCMilliseconds(msec);
  
  Return the "minutes" field of a Date (numerical):
  var minutes = mydate.getMinutes();
  Universal Time: mydate.getUTCMinutes();
  Set the minutes field
  mydate.setMinutes(minutes); mydate.setUTCMinutes(minutes);
  
  Return the "month" field of a Date (numerical, January=0):
  var month = mydate.getMonth();
  Universal Time: mydate.getUTCMonth();
  Set the month field:
  mydate.setMonth(month); mydate.setUTCMonth(month);
  
  Return the "seconds" field of a Date (numerical):
  var seconds = mydate.getSeconds();
  Universal Time: mydate.getUTCSeconds();
  Set the seconds field:
  mydate.setSeconds(seconds); mydate.setUTCSeconds(seconds);
  
  Return a Date in milliseconds since the epoch (0 = 1st Jan. 1970):
  var mtime = mydate.getTime();
  Set a Date in milliseconds since the epoch:
  mydate.setTime(mtime);
  
  Return the time difference for the current Date object compared to GMT:
  mydate.getTimezoneOffset();
  
  Return the "year" field of a Date (numerical):
  var year = mydate.getYear();
  Set the year field:
  mydate.setYear(year);
  
  Return a date converted into a universal time datestring.
  mydate.toGMTString();
  
  Return a date converted to a local time datestring:
  mydate.toLocaleString();
  
  Return a date as a datestring (no conversion of time zone):
  mydate.toString();
  
  Return a date converted to a universal time datestring.
  (Javascript 1.2 only - Use in preference to toGMTString(); )
  mydate.toUTCString();
  
  Return a date converted to a number:
  mydate.valueOf();
  
  
• Static Methods
  Parse a date/time string:
  Valid: Date.parse("Sat Mar 23 10:02:24 UTC 2002");
Invalid: Date.parse("Sat Mar 75 10:02:24 UTC 2002");
  
  Convert a date specification to milliseconds since the epoch:
  Date.UTC(2002,2,23,11,54,0,0);

Top

Older HTML tags and attributes that have been superseded by other more functional or flexible alternatives (whether as HTML or as CSS) are declared as deprecated in HTML4 by the W3C - the consortium that sets the HTML standards. Browsers should continue to support deprecated tags, but eventually these tags are likely to become obsolete and so future support cannot be guaranteed.
Top

A brief description of this web page on your site in your own words which is indexed by some search engines. Useful for frameset documents or pages with extensive Javascript in the head section. Sometimes only the first 20 words are processed. Some search engines object to the use of meta tags and may refuse to index your site if they are found, other engines encourage the use of the description and keyword meta tags.
Top

DHTML: Dynamic HTML (Hyper-Text Markup Language). Search for DHTML.
Top

Used for forms that contain input controls that do not need user input at the present time and can be specified for button, input, optgroup, option, select and textarea components. Can be set or unset using Javascript.
Top

display property: Display can be set to block, inline, list-item or none and can be specified for any element. display:none; causes the element to be completely removed from the page AND the space it would otherwise occupy is closed up dynamically, using whatever content follows the hidden element, (excluding elements using absolute positioning). display:block; re-creates the space required and displays the element as normal. Use list-item to add a bullet in front of the element (as in ul li) or use inline to create a new inline (i.e. relative positioning) box on the same line as previous content.
Top

If you create your graphics with a lot of different colour shades, you must bear in mind that not all visitors will be using monitors capable of such resolution. When the graphic is displayed by the browser, a certain amount of dithering occurs in an attempt to simulate the shade on the display. Two fixed colours are combined in a random dot pattern to create the illusion of the intended shade. This leads to grainy images and increases the final file size of any gif file. If you need lots of colour shades for an image, consider using a jpeg. Otherwise, try and maximise the areas of solid, uniform colour in your gif file and design your graphic in a low colour depth mode within your drawing software.
Top

div tag: Along with <span>, div was especially created as an HTML tag for use with style sheets. The div tag divides the content on screen using a line break above the <div> and below the </div> tag. <span> </span> tags are displayed without line breaks.
Top

• Properties
  Link details:
  document.alinkColor; Active link colour.
  document.linkColor; Initial link colour.
  document.vlinkColor; Visited link colour.
  document.links[0]; First link in this document. Provides access to each link sequentially, [1], [2], etc.
  

  ---

  Colours:
  document.bgColor; Background colour.
  document.fgColor; Default text colour.
  

  ---

  Although the document.forms[]; array provides access to forms sequentially, most applications use a name for the form and document.formname; but take care if you want to validate HTML4 pages using the name attribute in the <FORM> tag.
  document.images[]; provides sequential access to images in the form (in order of the position of the <img> tag, not the vertical position in the page).
  document.title; Contents of the <title> tag.
  document.url; Location of the document.
• Methods
  Clear the document:
  document.clear();
  Write to the document (content will be inserted in the document at the same point as the enclosing <script> tag).
  document.write("output");
  Append data and a newline to the document:
  document.writeln("data");

Top

Drop capitals are popular in certain forms of presentations or newsletters. CSS2 makes this easy, just specify a class in your stylesheet and add a contextual pseudo-element selector. For a drop-cap effect, use a paragraph class that doesn't use a text-indent setting and use text-align:justify for best effect. The rest of the paragraph style can be copied from other paragraphs on the page. Now create a contextual selector for this new class using the first-letter pseudo-element and the float style:
.drop {
font:12pt helvetica,tahoma,verdana,arial,sans-serif;
width:60%;
text-align:justify;
color:black;
background-color:white;
}
.drop:first-letter {
color:blue;
font-weight:800;
background:transparent;
font-size:3em;
line-height:0.9em;
float:left;
width:0.7em;
padding-right:2px;
}


Now each time you use p class="drop", the first-letter will be a drop-capital, the rest of the paragraph will flow around the drop-cap and other paragraphs are not affected. The important settings for effective drop-caps are font-weight, font-size, line-height, width and padding-right. Experiment with the values to get the effect you want. Note that even a change from line-height:1em to line-height:0.9em has a beneficial effect - too large and the drop-cap appears isolated from the paragraph, too small and you can get an overlap. Remember to test your styles in a variety of browsers to check you get what you expect - browsers still indulge in 'second-guessing' and try to compensate for almost-right code. The results of this guesswork are not entirely predictable!
Top