/// <summary>
/// Injects javascript libraries needed to satisfy feature dependencies.
/// </summary>
/// <param name="gadget"></param>
/// <param name="headTag"></param>
private void InjectFeatureLibraries(Gadget gadget, Node headTag)
{
// TODO: If there isn't any js in the document, we can skip this. Unfortunately, that means
// both script tags (easy to detect) and event handlers (much more complex).
GadgetContext context = gadget.getContext();
GadgetSpec spec = gadget.getSpec();
String forcedLibs = context.getParameter("libs");
HashKey <String> forced;
if (string.IsNullOrEmpty(forcedLibs))
{
forced = new HashKey <string>();
}
else
{
forced = new HashKey <string>();
foreach (var item in forcedLibs.Split(':'))
{
forced.Add(item);
}
}
// Forced libs are always done first.
if (forced.Count != 0)
{
String jsUrl = urlGenerator.getBundledJsUrl(forced, context);
Element libsTag = headTag.getOwnerDocument().createElement("script");
libsTag.setAttribute("src", jsUrl);
headTag.appendChild(libsTag);
// Forced transitive deps need to be added as well so that they don't get pulled in twice.
// TODO: Figure out a clean way to avoid having to call getFeatures twice.
foreach (GadgetFeature dep in featureRegistry.GetFeatures(forced))
{
forced.Add(dep.getName());
}
}
// Inline any libs that weren't forced. The ugly context switch between inline and external
// Js is needed to allow both inline and external scripts declared in feature.xml.
String container = context.getContainer();
ICollection <GadgetFeature> features = GetFeatures(spec, forced);
// Precalculate the maximum length in order to avoid excessive garbage generation.
int size = 0;
foreach (GadgetFeature feature in features)
{
foreach (JsLibrary library in feature.getJsLibraries(RenderingContext.GADGET, container))
{
if (library._Type == JsLibrary.Type.URL)
{
size += library.Content.Length;
}
}
}
// Really inexact.
StringBuilder inlineJs = new StringBuilder(size);
foreach (GadgetFeature feature in features)
{
foreach (JsLibrary library in feature.getJsLibraries(RenderingContext.GADGET, container))
{
if (library._Type == JsLibrary.Type.URL)
{
if (inlineJs.Length > 0)
{
Element inlineTag = headTag.getOwnerDocument().createElement("script");
headTag.appendChild(inlineTag);
inlineTag.appendChild(headTag.getOwnerDocument().createTextNode(inlineJs.ToString()));
inlineJs.Length = 0;
}
Element referenceTag = headTag.getOwnerDocument().createElement("script");
referenceTag.setAttribute("src", library.Content);
headTag.appendChild(referenceTag);
}
else
{
if (!forced.Contains(feature.getName()))
{
// already pulled this file in from the shared contents.
if (context.getDebug())
{
inlineJs.Append(library.DebugContent);
}
else
{
inlineJs.Append(library.Content);
}
inlineJs.Append(";\n");
}
}
}
}
inlineJs.Append(GetLibraryConfig(gadget, features));
if (inlineJs.Length > 0)
{
Element inlineTag = headTag.getOwnerDocument().createElement("script");
headTag.appendChild(inlineTag);
inlineTag.appendChild(headTag.getOwnerDocument().createTextNode(inlineJs.ToString()));
}
}