The use of style sheets for coding is a way that presentation structure can be separated from the detail of the content. For example, in web design, the markup language (i.e. HTML or XHTML) of a webpage contains the semantic content and structure for the page, but does not define its visual layout or style. The style is defined in an external file—the style sheet file—using a style sheet language such as CSS or XSLT. Previous to this design approach, the methodology was to have both style and structure defined by the markup language of a page. In short, a style sheet is a file that contains a set of rules which are used to impose formatting information on a data set or sets which are held as a separate file or files.
For example, in word processing and desktop publishing, a style sheet is a file or form that defines the layout of a document. The style sheet specifies parameters such as the page size, margins, and fonts. These parameters can then be carried over to a number of files or documents to give a uniform appearance for documents that contain different detailed content. Different style sheets can also be defined, for example, one for official reports, one for letters, one for team meeting memos or minutes, one for action plans, etc.
Prior to the advent and use of style sheet languages such as CSS, the commonest way to format a file was to include or contain the presentational attributes within the HTML markup; all font colours, background styles, element alignments, borders and sizes were coded within the HTML and as a consequence it was often required to repeat the information within the HTML. The advent of CSS allowed much of this formatting information to be moved to the style sheet file. This allowed the HTML language to be considerably simplified. Also, holding all the presentation styles in one file helped to significantly reduce maintenance time, and helps to reduce human error. For example, the font colour associated with a type of text element may be specified—and therefore easily modified—throughout an entire website simply by changing the line or lines of code in the style sheet file. The previous or alternate approach, using styles embedded in each individual page, required the same edit to be carried out for every page. As this was a cumbersome and time consuming process, errors tended to creep in due to human error.
An “external” style sheet file can be associated with an HTML document or documents to format the presentation of the document(s). Multiple style sheets can also be ‘called’ or imported. If multiple style sheets are used, these can be prioritised, with the style sheet with the highest priority controlling the content display. Declarations not set in the highest priority source are passed on to a source of lower priority, such as the user agent style. This process is called cascading.
A cascading style sheet is a style sheet that anticipates that other style sheets will either fill in or override the overall style sheet. This provides the designer the advantage of being able to rely on the basic style sheet when desired and overriding it when desired. The filling in or overriding can occur on a succession of “cascading” levels of style sheets. For example, one style sheet could be created and linked to from every separate page of a website as the overall style sheet (e.g. to set font type, font size, text colour, background, etc). For any portion of a page that includes a certain kind of content—for example, a catalogue of products—another style sheet can be used, this secondary style sheet amending the basic style sheet for that particular content. Another style sheet could be specified as applying to a particular type of product display.
As well as style sheets which control visual or display elements such as text size and colour, the style sheets may also include functional aspects. For example, the style sheet can include a function to sort data included in a file, as specified by the style sheet. It is also known to combine data tables with table specific style sheets which perform functions such as sorting, to create a table or similar which has an overall layout and look dictated by a style sheet, and where the data is sorted as dictated by a style sheet.
Although a separate style sheet or sheets can be created and applied to a page or data set as required to format the presentation or order of a document or documents, one issue with the use of style sheets is that for each particular required situation, an individual style sheet is still necessary. For multiple separate sets of data, it is still necessary to apply and maintain separate style sheets. If a number of different formats are potentially required, these will need to be thought out beforehand, and a number of style sheets will have to be created and prioritised/cascaded as required for each different format. This potentially requires the allocation of increased memory, and increased processing power to achieve the end result.
It is an object of the present invention to provide a method of sorting and visualising data which goes some way to overcoming the above-mentioned disadvantages or which at least provides the public or industry with a useful choice.
It is a further object of the present invention to provide an apparatus for sorting and visualising data which goes some way to overcoming the above-mentioned disadvantages or which at least provides the public or industry with a useful choice.
Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing the preferred embodiment of the invention without placing limitations thereon.
The background discussion (including any potential prior art) is not to be taken as an admission of the common general knowledge.