/** Computes the relative path from the current page to the given item. */
public static String getRelativeLinkTo(Item p) {
Map<Object, String> ancestors = new HashMap<Object, String>();
View view = null;
StaplerRequest request = Stapler.getCurrentRequest();
for (Ancestor a : request.getAncestors()) {
ancestors.put(a.getObject(), a.getRelativePath());
if (a.getObject() instanceof View) view = (View) a.getObject();
}
String path = ancestors.get(p);
if (path != null) return path;
Item i = p;
String url = "";
while (true) {
ItemGroup ig = i.getParent();
url = i.getShortUrl() + url;
if (ig == Hudson.getInstance()) {
assert i instanceof TopLevelItem;
if (view != null && view.contains((TopLevelItem) i)) {
// if p and the current page belongs to the same view, then return a relative path
return ancestors.get(view) + '/' + url;
} else {
// otherwise return a path from the root Hudson
return request.getContextPath() + '/' + p.getUrl();
}
}
path = ancestors.get(ig);
if (path != null) return path + '/' + url;
assert ig instanceof Item; // if not, ig must have been the Hudson instance
i = (Item) ig;
}
}
