/// <summary>
/// Gets the items of the specified type that are visible in the current scope.
/// If no match is found, returns null.
/// Caller must not modify the group returned.
/// </summary>
internal BuildItemGroup GetItems(string name)
{
// The visible items consist of the adds (accumulated as we go down)
// plus the first set of regular items we encounter
// minus any removes
BuildItemGroup allAdds = null;
BuildItemGroup allRemoves = null;
Dictionary <BuildItem, Dictionary <string, string> > allModifies = null;
BuildItemGroup groupFound = null;
foreach (LookupEntry entry in lookupEntries)
{
// Accumulate adds while we look downwards
if (entry.Adds != null)
{
BuildItemGroup adds = (BuildItemGroup)entry.Adds[name];
if (adds != null)
{
allAdds = CreateItemGroupIfNecessary(allAdds);
allAdds.ImportItems(adds);
}
}
// Accumulate removes while we look downwards
if (entry.Removes != null)
{
BuildItemGroup removes = (BuildItemGroup)entry.Removes[name];
if (removes != null)
{
allRemoves = CreateItemGroupIfNecessary(allRemoves);
allRemoves.ImportItems(removes);
}
}
// Accumulate modifications as we look downwards
if (entry.Modifies != null)
{
Dictionary <BuildItem, Dictionary <string, string> > modifies;
if (entry.Modifies.TryGetValue(name, out modifies))
{
if (allModifies == null)
{
allModifies = new Dictionary <BuildItem, Dictionary <string, string> >();
}
// We already have some modifies for this type
foreach (KeyValuePair <BuildItem, Dictionary <string, string> > modify in modifies)
{
// If earlier scopes modify the same metadata on the same item,
// they have priority
MergeModificationsIntoModificationTable(allModifies, modify, ModifyMergeType.FirstWins);
}
}
}
if (entry.Items != null)
{
groupFound = (BuildItemGroup)entry.Items[name];
if (groupFound != null)
{
// Found a group: we go no further
break;
}
}
if (entry.TruncateLookupsAtThisScope)
{
break;
}
}
if ((allAdds == null || allAdds.Count == 0) &&
(allRemoves == null || allRemoves.Count == 0) &&
(allModifies == null || allModifies.Count == 0))
{
// We can just hand out this group verbatim -
// that avoids any importing
if (groupFound == null)
{
groupFound = new BuildItemGroup();
}
return(groupFound);
}
// We have adds and/or removes and/or modifies to incorporate.
// We can't modify the group, because that might
// be visible to other batches; we have to create
// a new one.
BuildItemGroup result = new BuildItemGroup();
if (groupFound != null)
{
result.ImportItems(groupFound);
}
// Removes are processed after adds; this means when we remove there's no need to concern ourselves
// with the case where the item being removed is in an add table somewhere. The converse case is not possible
// using a project file: a project file cannot create an item that was already removed, it can only create
// a unique new item.
if (allAdds != null)
{
result.ImportItems(allAdds);
}
if (allRemoves != null)
{
result.RemoveItems(allRemoves);
}
// Modifies can be processed last; if a modified item was removed, the modify will be ignored
if (allModifies != null)
{
ApplyModifies(result, allModifies);
}
return(result);
}
