Starting to port Brail tests to new test approach.

[castle.git] / MonoRail / Castle.MonoRail.Views.Brail / BooViewEngine.cs

// Copyright 2004-2008 Castle Project - http://www.castleproject.org/
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

namespace Castle.MonoRail.Views.Brail
{
    using System;
    using System.Collections;
    using System.Collections.Generic;
    using System.Configuration;
    using System.IO;
    using System.Reflection;
    using System.Runtime.Serialization;
    using System.Text;
    using System.Threading;
    using System.Web;
    using Boo.Lang.Compiler;
    using Boo.Lang.Compiler.IO;
    using Boo.Lang.Compiler.Pipelines;
    using Boo.Lang.Compiler.Steps;
    using Boo.Lang.Parser;
    using Castle.Core.Logging;
    using Castle.MonoRail.Framework.Test;
    using Core;
    using Framework;

    public class BooViewEngine : ViewEngineBase, IInitializable
    {
        private static BooViewEngineOptions options;

        /// <summary>
        /// This field holds all the cache of all the 
        /// compiled types (not instances) of all the views that Brail nows of.
        /// </summary>
        private readonly Hashtable compilations = Hashtable.Synchronized(
            new Hashtable(StringComparer.InvariantCultureIgnoreCase));

        /// <summary>
        /// used to hold the constructors of types, so we can avoid using
        /// Activator (which takes a long time
        /// </summary>
        private readonly Hashtable constructors = new Hashtable();

        private string baseSavePath;

        /// <summary>
        /// This is used to add a reference to the common scripts for each compiled scripts
        /// </summary>
        private Assembly common;

        private ILogger logger;

        public override bool SupportsJSGeneration
        {
            get { return true; }
        }

        public override string ViewFileExtension
        {
            get { return ".brail"; }
        }

        public override string JSGeneratorFileExtension
        {
            get { return ".brailjs"; }
        }

        public string ViewRootDir
        {
            get { return ViewSourceLoader.ViewRootDir; }
        }

        public BooViewEngineOptions Options
        {
            get { return options; }
            set { options = value; }
        }

        #region IInitializable Members

        public void Initialize()
        {
            if (options == null) InitializeConfig();

            string baseDir = Path.GetDirectoryName(AppDomain.CurrentDomain.BaseDirectory);
            Log("Base Directory: " + baseDir);
            baseSavePath = Path.Combine(baseDir, options.SaveDirectory);
            Log("Base Save Path: " + baseSavePath);

            if (options.SaveToDisk && !Directory.Exists(baseSavePath))
            {
                Directory.CreateDirectory(baseSavePath);
                Log("Created directory " + baseSavePath);
            }

            CompileCommonScripts();

            ViewSourceLoader.ViewChanged += OnViewChanged;
        }

        #endregion

        // Process a template name and output the results to the user
        // This may throw if an error occured and the user is not local (which would 
        // cause the yellow screen of death)
        public override void Process(String templateName, TextWriter output, IEngineContext context, IController controller,
                                     IControllerContext controllerContext)
        {
            Log("Starting to process request for {0}", templateName);
            string file = templateName + ViewFileExtension;
            BrailBase view;
            // Output may be the layout's child output if a layout exists
            // or the context.Response.Output if the layout is null
            LayoutViewOutput layoutViewOutput = GetOutput(output, context, controller, controllerContext);
            // Will compile on first time, then save the assembly on the cache.
            view = GetCompiledScriptInstance(file, layoutViewOutput.Output, context, controller, controllerContext);
            if (controller != null)
                controller.PreSendView(view);

            Log("Executing view {0}", templateName);

            try
            {
                view.Run();
            }
            catch (Exception e)
            {
                HandleException(templateName, view, e);
            }

            if (layoutViewOutput.Layout != null)
            {
                layoutViewOutput.Layout.SetParent(view);

                try
                {
                    layoutViewOutput.Layout.Run();
                }
                catch (Exception e)
                {
                    HandleException(controllerContext.LayoutNames[0], layoutViewOutput.Layout, e);
                }
            }
            Log("Finished executing view {0}", templateName);
            if (controller != null)
                controller.PostSendView(view);
        }

        public override void Process(string templateName, string layoutName, TextWriter output,
                                     IDictionary<string, object> parameters)
        {
            ControllerContext controllerContext = new ControllerContext();
            if (layoutName != null)
            {
                controllerContext.LayoutNames = new string[] { layoutName };
            }
            foreach (KeyValuePair<string, object> pair in parameters)
            {
                controllerContext.PropertyBag[pair.Key] = pair.Value;
            };
            Process(templateName, output, null, null, controllerContext);
        }

        public override void ProcessPartial(string partialName, TextWriter output, IEngineContext context,
                                            IController controller, IControllerContext controllerContext)
        {
            Log("Generating partial for {0}", partialName);

            try
            {
                string file = ResolveTemplateName(partialName);
                BrailBase view = GetCompiledScriptInstance(file, output, context, controller, controllerContext);
                Log("Executing partial view {0}", partialName);
                view.Run();
                Log("Finished executing partial view {0}", partialName);
            }
            catch (Exception ex)
            {
                if (Logger != null && Logger.IsErrorEnabled)
                {
                    Logger.Error("Could not generate JS", ex);
                }

                throw new MonoRailException("Error generating partial: " + partialName, ex);
            }
        }

        public override object CreateJSGenerator(JSCodeGeneratorInfo generatorInfo, IEngineContext context,
                                                 IController controller,
                                                 IControllerContext controllerContext)
        {
            return new BrailJSGenerator(generatorInfo.CodeGenerator, generatorInfo.LibraryGenerator,
                                        generatorInfo.Extensions, generatorInfo.ElementExtensions);
        }

        public override void GenerateJS(string templateName, TextWriter output, JSCodeGeneratorInfo generatorInfo,
                                        IEngineContext context, IController controller, IControllerContext controllerContext)
        {
            Log("Generating JS for {0}", templateName);

            try
            {
                object generator = CreateJSGenerator(generatorInfo, context, controller, controllerContext);
                AdjustJavascriptContentType(context);
                string file = ResolveJSTemplateName(templateName);
                BrailBase view = GetCompiledScriptInstance(file,
                    //we use the script just to build the generator, not to output to the user
                                                           new StringWriter(),
                                                           context, controller, controllerContext);
                Log("Executing JS view {0}", templateName);
                view.AddProperty("page", generator);
                view.Run();

                output.WriteLine(generator);
                Log("Finished executing JS view {0}", templateName);
            }
            catch (Exception ex)
            {
                if (Logger != null && Logger.IsErrorEnabled)
                {
                    Logger.Error("Could not generate JS", ex);
                }

                throw new MonoRailException("Error generating JS. Template: " + templateName, ex);
            }
        }

        /// <summary>
        /// Wraps the specified content in the layout using the
        /// context to output the result.
        /// </summary>
        /// <param name="contents"></param>
        /// <param name="context"></param>
        /// <param name="controller"></param>
        /// <param name="controllerContext"></param>
        public override void RenderStaticWithinLayout(String contents, IEngineContext context, IController controller,
                                                      IControllerContext controllerContext)
        {
            LayoutViewOutput layoutViewOutput = GetOutput(context.Response.Output, context, controller, controllerContext);
            layoutViewOutput.Output.Write(contents);
            // here we don't need to pass parameters from the layout to the view, 
            if (layoutViewOutput.Layout != null)
            {
                layoutViewOutput.Layout.Run();
            }
        }

        private void HandleException(string templateName, BrailBase view, Exception e)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("Exception on process view: ").AppendLine(templateName);
            sb.Append("Last accessed variable: ").Append(view.LastVariableAccessed);
            string msg = sb.ToString();
            sb.Append("Exception: ").AppendLine(e.ToString());
            Log(msg);
            throw new MonoRailException(msg, e);
        }

        private void OnViewChanged(object sender, FileSystemEventArgs e)
        {
            string path = e.FullPath.Substring(ViewRootDir.Length);
            if (path.Length > 0 && (path[0] == Path.DirectorySeparatorChar ||
                                    path[0] == Path.AltDirectorySeparatorChar))
            {
                path = path.Substring(1);
            }
            if (path.IndexOf(options.CommonScriptsDirectory) != -1)
            {
                Log("Detected a change in commons scripts directory " + options.CommonScriptsDirectory + ", recompiling site");
                // need to invalidate the entire CommonScripts assembly
                // not worrying about concurrency here, since it is assumed
                // that changes here are rare. Note, this force a recompile of the 
                // whole site!
                try
                {
                    WaitForFileToBecomeAvailableForReading(e);
                    CompileCommonScripts();
                }
                catch (Exception ex)
                {
                    // we failed to recompile the commons scripts directory, but because we are running
                    // on another thread here, and exception would kill the application, so we log it 
                    // and continue on. CompileCommonScripts() will only change the global state if it has
                    // successfully compiled the commons scripts directory.
                    Log("Failed to recompile the commons scripts directory! {0}", ex);
                }
            }
            else
            {
                Log("Detected a change in {0}, removing from complied cache", e.Name);
                // Will cause a recompilation
                compilations[path] = null;
            }
        }

        private static void WaitForFileToBecomeAvailableForReading(FileSystemEventArgs e)
        {
            // We may need to wait while the file is being written and closed to disk
            int retries = 10;
            bool successfullyOpenedFile = false;
            while (retries != 0 && successfullyOpenedFile == false)
            {
                retries -= 1;
                try
                {
                    using (File.OpenRead(e.FullPath))
                    {
                        successfullyOpenedFile = true;
                    }
                }
                catch (IOException)
                {
                    //The file is probably in locked because it is currently being written to,
                    // will wait a while for it to be freed.
                    // again, this isn't something that need to be very robust, it runs on a separate thread
                    // and if it fails, it is not going to do any damage
                    Thread.Sleep(250);
                }
            }
        }

        public void SetViewSourceLoader(IViewSourceLoader loader)
        {
            ViewSourceLoader = loader;
        }

        // Get configuration options if they exists, if they do not exist, load the default ones
        // Create directory to save the compiled assemblies if required.
        // pre-compile the common scripts
        public override void Service(IServiceProvider serviceProvider)
        {
            base.Service(serviceProvider);
            ILoggerFactory loggerFactory = serviceProvider.GetService(typeof(ILoggerFactory)) as ILoggerFactory;
            if (loggerFactory != null)
                logger = loggerFactory.Create(GetType());
        }

        // Check if a layout has been defined. If it was, then the layout would be created
        // and will take over the output, otherwise, the context.Reposne.Output is used, 
        // and layout is null
        private LayoutViewOutput GetOutput(TextWriter output, IEngineContext context, IController controller,
                                           IControllerContext controllerContext)
        {
            BrailBase layout = null;
            if (controllerContext.LayoutNames != null && controllerContext.LayoutNames.Length != 0)
            {
                string layoutTemplate = controllerContext.LayoutNames[0];
                if (layoutTemplate.StartsWith("/") == false)
                {
                    layoutTemplate = "layouts\\" + layoutTemplate;
                }
                string layoutFilename = layoutTemplate + ViewFileExtension;
                layout = GetCompiledScriptInstance(layoutFilename, output,
                                                   context, controller, controllerContext);
                output = layout.ChildOutput = new StringWriter();
            }
            return new LayoutViewOutput(output, layout);
        }

        /// <summary>
        /// This takes a filename and return an instance of the view ready to be used.
        /// If the file does not exist, an exception is raised
        /// The cache is checked to see if the file has already been compiled, and it had been
        /// a check is made to see that the compiled instance is newer then the file's modification date.
        /// If the file has not been compiled, or the version on disk is newer than the one in memory, a new
        /// version is compiled.
        /// Finally, an instance is created and returned        
        /// </summary>
        public BrailBase GetCompiledScriptInstance(
            string file,
            TextWriter output,
            IEngineContext context,
            IController controller, IControllerContext controllerContext)
        {
            bool batch = options.BatchCompile;

            // normalize filename - replace / or \ to the system path seperator
            string filename = file.Replace('/', Path.DirectorySeparatorChar)
                .Replace('\\', Path.DirectorySeparatorChar);

            Log("Getting compiled instnace of {0}", filename);

            Type type;

            if (compilations.ContainsKey(filename))
            {
                type = (Type)compilations[filename];
                if (type != null)
                {
                    Log("Got compiled instance of {0} from cache", filename);
                    return CreateBrailBase(context, controller, controllerContext, output, type);
                }
                // if file is in compilations and the type is null,
                // this means that we need to recompile. Since this usually means that 
                // the file was changed, we'll set batch to false and procceed to compile just
                // this file.
                Log("Cache miss! Need to recompile {0}", filename);
                batch = false;
            }

            type = CompileScript(filename, batch);

            if (type == null)
            {
                throw new MonoRailException("Could not find a view with path " + filename);
            }

            return CreateBrailBase(context, controller, controllerContext, output, type);
        }

        private BrailBase CreateBrailBase(IEngineContext context, IController controller, IControllerContext controllerContext,
                                          TextWriter output, Type type)
        {
            ConstructorInfo constructor = (ConstructorInfo)constructors[type];
            BrailBase self = (BrailBase)FormatterServices.GetUninitializedObject(type);
            constructor.Invoke(self, new object[] { this, output, context, controller, controllerContext });
            return self;
        }

        // Compile a script (or all scripts in a directory), save the compiled result
        // to the cache and return the compiled type.
        // If an error occurs in batch compilation, then an attempt is made to compile just the single
        // request file.
        public Type CompileScript(string filename, bool batch)
        {
            IDictionary<ICompilerInput, string> inputs2FileName = GetInput(filename, batch);
            string name = NormalizeName(filename);
            Log("Compiling {0} to {1} with batch: {2}", filename, name, batch);
            CompilationResult result = DoCompile(inputs2FileName.Keys, name);

            if (result.Context.Errors.Count > 0)
            {
                if (batch == false)
                {
                    RaiseCompilationException(filename, inputs2FileName, result);
                }
                //error compiling a batch, let's try a single file
                return CompileScript(filename, false);
            }
            Type type;
            foreach (ICompilerInput input in inputs2FileName.Keys)
            {
                string viewName = Path.GetFileNameWithoutExtension(input.Name);
                string typeName = TransformToBrailStep.GetViewTypeName(viewName);
                type = result.Context.GeneratedAssembly.GetType(typeName);
                Log("Adding {0} to the cache", type.FullName);
                compilations[inputs2FileName[input]] = type;
                constructors[type] = type.GetConstructor(new Type[]
                                                                                {
                                                                                        typeof(BooViewEngine),
                                                                                        typeof(TextWriter),
                                                                                        typeof(IEngineContext),
                                                                                        typeof(IController),
                                                                                        typeof(IControllerContext)
                                                                                });
            }
            type = (Type)compilations[filename];
            return type;
        }

        private void RaiseCompilationException(string filename, IDictionary<ICompilerInput, string> inputs2FileName,
                                               CompilationResult result)
        {
            string errors = result.Context.Errors.ToString(true);
            Log("Failed to compile {0} because {1}", filename, errors);
            StringBuilder code = new StringBuilder();
            foreach (ICompilerInput input in inputs2FileName.Keys)
            {
                code.AppendLine()
                    .Append(result.Processor.GetInputCode(input))
                    .AppendLine();
            }
            throw new HttpParseException("Error compiling Brail code",
                                         result.Context.Errors[0],
                                         filename,
                                         code.ToString(), result.Context.Errors[0].LexicalInfo.Line);
        }

        // If batch compilation is set to true, this would return all the view scripts
        // in the director (not recursive!)
        // Otherwise, it would return just the single file
        private IDictionary<ICompilerInput, string> GetInput(string filename, bool batch)
        {
            Dictionary<ICompilerInput, string> input2FileName = new Dictionary<ICompilerInput, string>();
            if (batch == false)
            {
                input2FileName.Add(CreateInput(filename), filename);
                return input2FileName;
            }
            // use the System.IO.Path to get the folder name even though
            // we are using the ViewSourceLoader to load the actual file
            string directory = Path.GetDirectoryName(filename);
            foreach (string file in ViewSourceLoader.ListViews(directory))
            {
                ICompilerInput input = CreateInput(file);
                input2FileName.Add(input, file);
            }
            return input2FileName;
        }

        // create an input from a resource name
        public ICompilerInput CreateInput(string name)
        {
            IViewSource viewSrc = ViewSourceLoader.GetViewSource(name);
            if (viewSrc == null)
            {
                throw new MonoRailException("{0} is not a valid view", name);
            }
            // I need to do it this way because I can't tell 
            // when to dispose of the stream. 
            // It is not expected that this will be a big problem, the string
            // will go away after the compile is done with them.
            using (StreamReader stream = new StreamReader(viewSrc.OpenViewStream()))
            {
                return new StringInput(name, stream.ReadToEnd());
            }
        }

        /// <summary>
        /// Perform the actual compilation of the scripts
        /// Things to note here:
        /// * The generated assembly reference the Castle.MonoRail.MonoRailBrail and Castle.MonoRail.Framework assemblies
        /// * If a common scripts assembly exist, it is also referenced
        /// * The AddBrailBaseClassStep compiler step is added - to create a class from the view's code
        /// * The ProcessMethodBodiesWithDuckTyping is replaced with ReplaceUknownWithParameters
        ///   this allows to use naked parameters such as (output context.IsLocal) without using 
        ///   any special syntax
        /// * The FixTryGetParameterConditionalChecks is run afterward, to transform "if ?Error" to "if not ?Error isa IgnoreNull"
        /// * The ExpandDuckTypedExpressions is replace with a derived step that allows the use of Dynamic Proxy assemblies
        /// * The IntroduceGlobalNamespaces step is removed, to allow to use common variables such as 
        ///   date and list without accidently using the Boo.Lang.BuiltIn versions
        /// </summary>
        /// <param name="files"></param>
        /// <param name="name"></param>
        /// <returns></returns>
        private CompilationResult DoCompile(IEnumerable<ICompilerInput> files, string name)
        {
            ICompilerInput[] filesAsArray = new List<ICompilerInput>(files).ToArray();
            BooCompiler compiler = SetupCompiler(filesAsArray);
            string filename = Path.Combine(baseSavePath, name);
            compiler.Parameters.OutputAssembly = filename;
            // this is here and not in SetupCompiler since CompileCommon is also
            // using SetupCompiler, and we don't want reference to the old common from the new one
            if (common != null)
                compiler.Parameters.References.Add(common);
            // pre procsssor needs to run before the parser
            BrailPreProcessor processor = new BrailPreProcessor(this);
            compiler.Parameters.Pipeline.Insert(0, processor);
            // inserting the add class step after the parser
            compiler.Parameters.Pipeline.Insert(2, new TransformToBrailStep(options));
            compiler.Parameters.Pipeline.Replace(typeof(ProcessMethodBodiesWithDuckTyping),
                                                 new ReplaceUknownWithParameters());
            compiler.Parameters.Pipeline.Replace(typeof(ExpandDuckTypedExpressions),
                                                 new ExpandDuckTypedExpressions_WorkaroundForDuplicateVirtualMethods());
            compiler.Parameters.Pipeline.Replace(typeof(InitializeTypeSystemServices),
                                                 new InitializeCustomTypeSystem());
            compiler.Parameters.Pipeline.InsertBefore(typeof(ReplaceUknownWithParameters),
                                                      new FixTryGetParameterConditionalChecks());
            compiler.Parameters.Pipeline.RemoveAt(compiler.Parameters.Pipeline.Find(typeof(IntroduceGlobalNamespaces)));

            return new CompilationResult(compiler.Run(), processor);
        }

        // Return the output filename for the generated assembly
        // The filename is dependant on whatever we are doing a batch
        // compile or not, if it's a batch compile, then the directory name
        // is used, if it's just a single file, we're using the file's name.
        // '/' and '\' are replaced with '_', I'm not handling ':' since the path
        // should never include it since I'm converting this to a relative path
        public string NormalizeName(string filename)
        {
            string name = filename;
            name = name.Replace(Path.AltDirectorySeparatorChar, '_');
            name = name.Replace(Path.DirectorySeparatorChar, '_');

            return name + "_BrailView.dll";
        }

        // Compile all the common scripts to a common assemblies
        // an error in the common scripts would raise an exception.
        public bool CompileCommonScripts()
        {
            if (options.CommonScriptsDirectory == null)
                return false;

            // the demi.boo is stripped, but GetInput require it.
            string demiFile = Path.Combine(options.CommonScriptsDirectory, "demi.brail");
            IDictionary<ICompilerInput, string> inputs = GetInput(demiFile, true);
            ICompilerInput[] inputsAsArray = new List<ICompilerInput>(inputs.Keys).ToArray();
            BooCompiler compiler = SetupCompiler(inputsAsArray);
            string outputFile = Path.Combine(baseSavePath, "CommonScripts.dll");
            compiler.Parameters.OutputAssembly = outputFile;
            CompilerContext result = compiler.Run();
            if (result.Errors.Count > 0)
                throw new MonoRailException(result.Errors.ToString(true));
            common = result.GeneratedAssembly;
            compilations.Clear();
            return true;
        }

        // common setup for the compiler
        private static BooCompiler SetupCompiler(IEnumerable<ICompilerInput> files)
        {
            BooCompiler compiler = new BooCompiler();
            compiler.Parameters.Ducky = true;
            compiler.Parameters.Debug = options.Debug;
            if (options.SaveToDisk)
                compiler.Parameters.Pipeline = new CompileToFile();
            else
                compiler.Parameters.Pipeline = new CompileToMemory();
            // replace the normal parser with white space agnostic one.
            compiler.Parameters.Pipeline.RemoveAt(0);
            compiler.Parameters.Pipeline.Insert(0, new WSABooParsingStep());
            foreach (ICompilerInput file in files)
            {
                compiler.Parameters.Input.Add(file);
            }
            foreach (Assembly assembly in options.AssembliesToReference)
            {
                compiler.Parameters.References.Add(assembly);
            }
            compiler.Parameters.OutputType = CompilerOutputType.Library;
            return compiler;
        }

        private static void InitializeConfig()
        {
            InitializeConfig("brail");

            if (options == null)
            {
                InitializeConfig("Brail");
            }

            if (options == null)
            {
                options = new BooViewEngineOptions();
            }
        }

        private static void InitializeConfig(string sectionName)
        {
            options = ConfigurationManager.GetSection(sectionName) as BooViewEngineOptions;
        }

        private void Log(string msg, params object[] items)
        {
            if (logger == null || logger.IsDebugEnabled == false)
                return;
            logger.DebugFormat(msg, items);
        }

        public bool ConditionalPreProcessingOnly(string name)
        {
            return String.Equals(
                Path.GetExtension(name),
                JSGeneratorFileExtension,
                StringComparison.InvariantCultureIgnoreCase);
        }

        #region Nested type: CompilationResult

        private class CompilationResult
        {
            private readonly CompilerContext context;
            private readonly BrailPreProcessor processor;

            public CompilationResult(CompilerContext context, BrailPreProcessor processor)
            {
                this.context = context;
                this.processor = processor;
            }

            public CompilerContext Context
            {
                get { return context; }
            }

            public BrailPreProcessor Processor
            {
                get { return processor; }
            }
        }

        #endregion

        #region Nested type: LayoutViewOutput

        private class LayoutViewOutput
        {
            private readonly BrailBase layout;
            private readonly TextWriter output;

            public LayoutViewOutput(TextWriter output, BrailBase layout)
            {
                this.layout = layout;
                this.output = output;
            }

            public BrailBase Layout
            {
                get { return layout; }
            }

            public TextWriter Output
            {
                get { return output; }
            }
        }

        #endregion
    }
}