When thinking about how you want a navigation menu to be displayed it is best to consider what is to be displayed for a page several levels into the site.
For example consider the following site navigation tree:
| Abs Level | 0 | 1 | 2 | 3 | 4 | 5 |
| Relative Level | -3 | -2 | -1 | +0 | +1 | +2 |
| Home | Welcome | |||||
| Products | Electrical | White Goods | Freezers | |||
| Fridges | ||||||
| MultiMedia | Hi-Fi's | |||||
| TV's | Plasma | |||||
| CRT | ||||||
| DVD's | ||||||
| Gardening | Fences | |||||
| Tools | ||||||
| Contact Us |
For the examples below we will use this navigation tree and will assume that the page "MultiMedia" is being built by WebBuild.
The parts of this tree that are displayed on each page being built page are determined by six parameters listed below in the site navigation properies file. The values of these parameters are either absolute levels or relative levels (relative levels always have a plus or minus sign preceeding the number). Because relative levels can be used, the actual navigation links shown on each built page can be different.
TopLevel and BottomLevel (default levels: 0 and +1) - These parameters set the highest and lowest navigation links be displayed (inclusive). In the case of the "Multimedia page the default settings would result in the levels 0 thro 4 (relative level +1). Not all navigation links are displayed - for levels above and equal to the current page are displayed the nanigation link is displayed if it is on the path of the current page - for levels below the current page links are displayed if the current page is on the path to them.
TopDisplayIfParentOnPath and BottomDisplayIfParentOnPath (default levels 0 and 999) - The parameters work in conjection with the TopLevel and BottomLevel settings. The settings have no affect on navigation links below the current page, however on pages above or level with the current page, navigaion links are displayed if the parent of that link is on the path to the current page (and is at a level between the xxxDisplayIfParentOnPath parameters. Navigation links a bove TopLevel and below BottomLevel are not displayed - it is typical to enable this behavior with values of 0 and 999, or disable this behavior with values of 999 and 999 respecivly.
TopDisplayAll and BottomDisplayAll (default values 999 and 999) - As well as the above 4 parameters for displaying navigaion links the TopDisplay all and BottomDisplayAll parameters can used to display additional navigation links (or can be used exclusivly to display navigation links if TopLeveL and BottomLevel are set to 999 and 999 respectivly). By default this feature is not enabled. The TopDisplayAll sets the point at which Link candidates for display are considered - if the TopDisplayAll is set to 0 then all links in the tree are displayed down to the level set by BottomDisplayAll. If TopDisplayAll is non zero, sections of tree relevent to the current page are condidered for display. For example, if the TopDisplayAll level is set to 2 in the navigation tree above then candidate sub-trees for display are all links in sections "Electrical" or "Gardening" or no links at all - the "Electicals" section is displayed if the current page is "Electrical" or directly below "Electrical" - if the current page is above level 2 neither tree is a candidate). BottomDisplayAll sets the lower limit for display.
The rest of the parameters in the navigation properties page are described in the How it is Displayed page.
Examples - Items in red are displayed - assuming the current page being built is "MultiMedia":
| TopLevel | 0 | TopDisplayIfParentOnPath | 999 | TopDisplayAll | 999 |
| BottomLevel | 999 | BottomDisplayIfParentOnPath | 999 | BottomDisplayAll | 999 |
| Home | Welcome | ||
| Products | Electrical | White Goods | Freezers |
| Fridges | |||
| MultiMedia | Hi-Fi's | ||
| TV's | Plasma | ||
| CRT | |||
| DVD's | |||
| Gardening | Fences | ||
| Tools | |||
| Contact Us |
This Example shows the links that would be displayed on the "MultiMedia" page if the full extent of TopLevel and BottomLevel are used and the other parameters are set such they have no effect. If you wish to display just the path to the current page simply change the BottomLevel to +0.
| TopLevel | 1 | TopDisplayIfParentOnPath | 0 | TopDisplayAll | 999 |
| BottomLevel | +1 | BottomDisplayIfParentOnPath | 999 | BottomDisplayAll | 999 |
| Home | Welcome | ||
| Products | Electrical | White Goods | Freezers |
| Fridges | |||
| MultiMedia | Hi-Fi's | ||
| TV's | Plasma | ||
| CRT | |||
| DVD's | |||
| Gardening | Fences | ||
| Tools | |||
| Contact Us |
Compaired to the last example this example brings the full force of the xxxDisplayParentIfOnPath Settings. "White Goods" is diplayed because it's parent, "Electrical", is on the Path. "Gardening" is displayed because it's parent, "Products" is on the path and so on up the tree. "Plasma" and "CRT" are no longer displayed because the are at a level lower than BottomLevel (which is set to +1). "Home" is no longer displayed because it is at a level above TopLevel (which is set to 1). Note: "Contact Us" is displayed because "Home" is on the Path - even though "Home" is not displayed.
| TopLevel | 999 | TopDisplayIfParentOnPath | 0 | TopDisplayAll | 2 |
| BottomLevel | 999 | BottomDisplayIfParentOnPath | 999 | BottomDisplayAll | 4 |
| Home | Welcome | ||
| Products | Electrical | White Goods | Freezers |
| Fridges | |||
| MultiMedia | Hi-Fi's | ||
| TV's | Plasma | ||
| CRT | |||
| DVD's | |||
| Gardening | Fences | ||
| Tools | |||
| Contact Us |
Here we are only using the TopDisplayAll and BottomDisplayAll parameters to display a section of the navigaion tree. Because the current page is "MultiMedia" Links immediatly below "Electrical" (level 2) are displayed to level4. If the current page was say "Tools" then this setting would show the three links "Gardening", "Fences" and "Tools". No links would be displayed if the current page was say "Contact Us".
| TopLevel | 1 | TopDisplayIfParentOnPath | 0 | TopDisplayAll | 2 |
| BottomLevel | +1 | BottomDisplayIfParentOnPath | 999 | BottomDisplayAll | 4 |
| Home | Welcome | ||
| Products | Electrical | White Goods | Freezers |
| Fridges | |||
| MultiMedia | Hi-Fi's | ||
| TV's | Plasma | ||
| CRT | |||
| DVD's | |||
| Gardening | Fences | ||
| Tools | |||
| Contact Us |
If we blend the previous two examples this is the result.
Notes
Don't forget that any of the levels you specify in any of these parameters can be an absolute level (0 = home) or a relative level (+0 = current page level, -1 parent page level etc).
Blank, or poorly formatted values are ignored and their default values are substituted.
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