We are now trying to build a map library like google/bing/yahoo,we will use it offline.
However I found that I have no idea about how to arange the divs in the page,since there are some many different types of divs.
1) the map tiles (small image 256X256)
2)the overlayer(marker/informationwindow/polygon...)
3)the control.
I have to try to read the html source codes of google and bing and etc. But I found it is difficult to understand them.
For exmaple,this frangment is copyed from another online map site of China.
As you can see,it is just a exmaple for how to adding a marker to the map.
But take the code,there are so many nested divs,most of them have the property of “width:0;height:0”,I do not know why?
Since in my opinion,the marker is just an icon,just put it in the page.
Why use so many nested divs and even the “map” tag?
But I think they must have the advantages which I can not find.
Any one can give some suggestions?
Typically you insert a div in HTML when you want to create a block element but there is no more semantically-loaded element available with the correct meaning.
I think the answer to your question is to use just as many div elements as you need for your purposes. Do not add more just because you can. Sometimes you don’t need any div elements at all – you can use other more meaningful elements such as img, ul, p, etc. You can sometimes avoid inserting a wrapping div by using CSS to change an inline element such as a into a block element.
If you need more later then add them later. Don’t worry about what Google/Bing/Yahoo do. Their requirements are probably different to yours.