/// <summary>
/// Generates composite Javascript from a list of scripts
/// </summary>
/// <param name="webConnection"></param>
/// <param name="scriptUrls"></param>
/// <returns></returns>
private string GenerateCompositeJavascript(IWebConnection webConnection, IEnumerable<string> scriptUrls)
{
StringBuilder scriptBuilder = new StringBuilder();
foreach (string scriptUrl in scriptUrls)
{
try
{
IWebResults webResult = webConnection.ShellTo(scriptUrl);
int statusCode = (int)webResult.Status;
if ((statusCode >= 200) && (statusCode < 300))
{
string script = webResult.ResultsAsString;
script = JavaScriptMinifier.Instance.Minify(script);
scriptBuilder.AppendFormat("\n// {0}\n", scriptUrl);
scriptBuilder.Append("try {");
scriptBuilder.Append(script);
scriptBuilder.Append("} catch (exception) { }");
// Note: exceptions are swallowed
// This form of compression shouldn't be used when a developer is trying to debug, instead, they should
// turn on Javascript debug mode, which disables this compression and allows them to use the browser's
// debugger
}
}
catch (Exception e)
{
log.Error("Error loading script in GenerateCompositeJavascript for script " + scriptUrl, e);
}
}
return scriptBuilder.ToString();
}
/// <summary>
/// Given an enumeration of script names, this returns ALL of the scripts that are needed, and their MD5s for caching. This
/// recursively inspects scripts to find dependant scripts underneath
/// </summary>
/// <param name="requestedScripts"></param>
/// <param name="addedScripts">Scripts that have already been added through script tags</param>
/// <returns></returns>
public IEnumerable<ScriptAndMD5> DetermineDependantScripts(IEnumerable<string> requestedScripts, IWebConnection webConnection)
{
List<string> uninspected = new List<string>();
// resolve user variables like [blahblah]
foreach (string requestedScript in requestedScripts)
uninspected.Add(webConnection.ResolveUserVariables(requestedScript));
requestedScripts = uninspected.ToArray();
// Each needed script, and the scripts that it depends on
Dictionary<string, List<string>> dependancies = new Dictionary<string, List<string>>();
// Cache of loaded scripts
Dictionary<string, string> loadedScriptCache = new Dictionary<string, string>();
// Find all of the needed scripts
while (uninspected.Count > 0)
{
// These are all of the scripts that this script depends on
List<string> scriptDependancies = new List<string>();
string scriptToInspect = uninspected[0];
uninspected.RemoveAt(0);
if (!webConnection.Scripts.Contains(scriptToInspect))
{
IWebResults shelledScript = webConnection.ShellTo(scriptToInspect);
if (null != shelledScript)
{
string script = shelledScript.ResultsAsString;
loadedScriptCache[scriptToInspect] = script;
string firstLine = script.Split('\n', '\r')[0];
if (firstLine.StartsWith("// Scripts:"))
{
string unbrokenScripts = firstLine.Substring(11).Trim(); // (The list of scripts must be all on the first line, seperated by commas)
foreach (string dependantScriptUntrimmed in unbrokenScripts.Split(','))
{
string dependantScript = webConnection.ResolveUserVariables(dependantScriptUntrimmed.Trim());
// If the script hasn't been scanned, queue it for scanning
if (!uninspected.Contains(dependantScript))
if (!dependancies.ContainsKey(dependantScript))
uninspected.Add(dependantScript);
scriptDependancies.Add(dependantScript);
}
}
dependancies[scriptToInspect] = scriptDependancies;
}
}
}
// Now that all of the needed scripts, and what depends on what are known, create a complete list of needed
// scripts, sorted so that the lowest-level dependancy comes first
List<string> sortedDependancies = new List<string>();
SortDependantScriptsHelper(requestedScripts, dependancies, sortedDependancies);
// Calculate the results to return
List<ScriptAndMD5> toReturn = new List<ScriptAndMD5>();
foreach (string scriptName in sortedDependancies)
if (!webConnection.Scripts.Contains(scriptName))
{
ScriptAndMD5 scriptAndMD5 = new ScriptAndMD5();
scriptAndMD5.ScriptName = scriptName;
byte[] scriptBytes = System.Text.Encoding.UTF8.GetBytes(loadedScriptCache[scriptName]);
// Get a free hash calculator
MD5CryptoServiceProvider hashAlgorithm = StaticRecycler<MD5CryptoServiceProvider>.Get();
byte[] scriptHash;
try
{
scriptHash = hashAlgorithm.ComputeHash(scriptBytes);
}
finally
{
// Save the hash calculator for reuse
StaticRecycler<MD5CryptoServiceProvider>.Recycle(hashAlgorithm);
}
scriptAndMD5.MD5 = Convert.ToBase64String(scriptHash);
toReturn.Add(scriptAndMD5);
webConnection.Scripts.Add(scriptName);
}
return toReturn;
}