Re: How do I make a HTML tree for a set of nodes?

Hi, On Sunday 04 June 2006 19:08, tedd wrote: > At 3:38 PM +0200 6/4/06, Niels wrote: >>On Sunday 04 June 2006 15:30, tedd wrote: >> >>[snip] >> >>> You can dynamically generate a table and place text (and/or color) the >>> cells that are nodes -- that would be my approach. You would need to >>> know the width and depth of the tree and then just fill in the cells >>> that are nodes. >>> >>> hth's >>> >>> tedd >> >>Yes, well... It's a tad more complicated I think. Yes, I can make a table, >>finding the dimensions shouldn't be a big problem. Placing the nodes in >>the right cells isn't as easy, and making the connections is downright >>difficult. >> >>A problem with using a table is that cells can't be individually sized. >>However DIVs or TDs is a minor problem. The major problem is to walk >>through the tree properly (recursively probably), and remember the >>connections. And then rendering them... > > I've done this before, but not with html. > > My demo is at: > > http://www.sperling.com/freeware.php > > So, I have an idea of what's involved. > > If this just for display, then it shouldn't be too difficult to display > the end results in a table -- provided, you know in advance the largest > any row will be. It will be a simple grid, unless you want to play with > column spacing, which will be very difficult indeed to manage. > > As for cells not being individually sized, you're right they can't be > sized, but they do automatically size to their contents and that can be > varied as well shown with different background colors. > > Are you going to use this for something other than display, is it > functional in some way? Because if you're going to add functionality, such > as editing, deleting, sorting, then you have a big chore in front of you. > > As for using recursive functions, absolutely -- they make the process (and > code) much less. However, you need to wrap your mind around things > spinning around to their conclusion, which is sometimes difficult to > imagine. > > Good luck. > > tedd Thank you for your answer, I appreciate it! Years ago I made Javascript navigation tree -- like a file browser, with expandable branches and so on. It was a big problem to parse all the relationships to img tags and links. I just had a looks at that code -- 10 years old, and it works! I couldn't change it to my current needs though. As I said elsewhere on this thread, I've settled for a simple, indented tree-view. Each node is a link and some text, and it's all reasonably easy to understand. And it's a small function -- I know about the dangers of recursion. Choosing this simple layout will also make it easier to render the output to PDF at a later stage. If I were to make a "real" tree, I wouldn't use a table. It's too difficult to manage IMO. I'd probably look for a generic graph algorithm somewhere, and try some dhtml voodoo with flying DIVs. Thanks again, Niels