MR-262 - Dynamic components in brail using RenderComponent

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

// Copyright 2004-2007 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.

using System.Diagnostics;
using System.Text;

namespace Castle.MonoRail.Views.Brail
{
        using System;
        using System.Collections;
        using System.IO;
        using Castle.MonoRail.Framework;
        /// <summary>
        ///Base class for all the view scripts, this is the class that is responsible for
        /// support all the behind the scenes magic such as variable to PropertyBag trasnlation, 
        /// resources usage, etc. 
        /// </summary>
        public abstract class BrailBase
        {
                private TextWriter outputStream;

                /// <summary>
                /// This is used by layout scripts only, for outputing the child's content
                /// </summary>
                protected TextWriter childOutput;
                private Hashtable properties;
                /// <summary>
                /// used to hold the ComponentParams from the view, so their views/sections could access them
                /// </summary>
                private IList viewComponentsParameters;

                protected IRailsEngineContext context;
                protected Controller __controller;
                protected BooViewEngine viewEngine;

                /// <summary>
                /// usually used by the layout to refer to its view, or a subview to its parent
                /// </summary>
                protected BrailBase parent;

                /// <summary>
                /// Initializes a new instance of the <see cref="BrailBase"/> class.
                /// </summary>
                /// <param name="viewEngine">The view engine.</param>
                /// <param name="output">The output.</param>
                /// <param name="context">The context.</param>
                /// <param name="__controller">The controller.</param>
                public BrailBase(BooViewEngine viewEngine, TextWriter output, IRailsEngineContext context, Controller __controller)
                {
                        this.viewEngine = viewEngine;
                        this.outputStream = output;
                        this.context = context;
                        this.__controller = __controller;
                        InitProperties(context, __controller);
                }

                /// <summary>
                /// Runs this instance, this is generated by the script
                /// </summary>
                public abstract void Run();


                /// <summary>
                ///The path of the script, this is filled by AddBrailBaseClassStep
                /// and is used for sub views 
                /// </summary>
                public virtual string ScriptDirectory
                {
                        get { return viewEngine.ViewRootDir; }
                }

                /// <summary>
                /// Gets the view engine.
                /// </summary>
                /// <value>The view engine.</value>
                public BooViewEngine ViewEngine
                {
                        get { return viewEngine; }
                }

                /// <summary>
                /// Output the subview to the client, this is either a relative path "SubView" which
                /// is relative to the current /script/ or an "absolute" path "/home/menu" which is
                /// actually relative to ViewDirRoot
                /// </summary>
                /// <param name="subviewName"></param>
                public void OutputSubView(string subviewName)
                {
                        OutputSubView(subviewName, new Hashtable());
                }

                /// <summary>
                /// Similiar to the OutputSubView(string) function, but with a bunch of parameters that are used
                /// just for this subview. This parameters are /not/ inheritable.
                /// </summary>
                /// <param name="subviewName"></param>
                /// <param name="parameters"></param>
                public void OutputSubView(string subviewName, IDictionary parameters)
                {
                        OutputSubView(subviewName, outputStream, parameters);
                }

                /// <summary>
                /// Outputs the sub view to the writer
                /// </summary>
                /// <param name="subviewName">Name of the subview.</param>
                /// <param name="writer">The writer.</param>
                /// <param name="parameters">The parameters.</param>
                public void OutputSubView(string subviewName, TextWriter writer, IDictionary parameters)
                {
                        string subViewFileName = GetSubViewFilename(subviewName);
                        BrailBase subView = viewEngine.GetCompiledScriptInstance(subViewFileName, writer, context, __controller);
                        subView.SetParent(this);
                        foreach (DictionaryEntry entry in parameters)
                        {
                                subView.properties[entry.Key] = entry.Value;
                        }
                        subView.Run();
                }

                /// <summary>
                /// Get the sub view file name, if the subview starts with a '/' 
                /// then the filename is considered relative to ViewDirRoot
                /// otherwise, it's relative to the current script directory
                /// </summary>
                /// <param name="subviewName"></param>
                /// <returns></returns>
                public string GetSubViewFilename(string subviewName)
                {
                        //absolute path from Views directory
                        if (subviewName[0] == '/')
                                return subviewName.Substring(1) + viewEngine.ViewFileExtension;
                        return Path.Combine(ScriptDirectory, subviewName) + viewEngine.ViewFileExtension;
                }

                /// <summary>
                /// this is called by ReplaceUnknownWithParameters step to create a more dynamic experiance
                /// any uknown identifier will be translate into a call for GetParameter('identifier name').
                /// This mean that when an uknonwn identifier is in the script, it will only be found on runtime.
                /// </summary>
                /// <param name="name"></param>
                /// <returns></returns>
                public object GetParameter(string name)
                {
                        ParameterSearch search = GetParameterInternal(name);
                        if (search.Found == false)
                                throw new RailsException("Parameter '" + name + "' was not found!");
                        return search.Value;
                }

                /// <summary>
                /// this is called by ReplaceUnknownWithParameters step to create a more dynamic experiance
                /// any uknown identifier with the prefix of ? will be translated into a call for 
                /// TryGetParameter('identifier name without the ? prefix').
                /// This method will return null if the value it not found.
                /// </summary>
                /// <param name="name"></param>
                /// <returns></returns>
                public object TryGetParameter(string name)
                {
                        ParameterSearch search = GetParameterInternal(name);
                        return search.Value;
                }

                /// <summary>
                /// Gets the parameter - implements the logic for searching parameters.
                /// </summary>
                /// <param name="name">The name.</param>
                /// <returns></returns>
                private ParameterSearch GetParameterInternal(string name)
                {
                        //temporary syntax to turn @variable to varaible, imitating :symbol in ruby
                        if (name.StartsWith("@"))
                                return new ParameterSearch(name.Substring(1), true);
                        if (viewComponentsParameters != null)
                        {
                                foreach (IDictionary viewComponentProperties in viewComponentsParameters)
                                {
                                        if (viewComponentProperties.Contains(name))
                                                return new ParameterSearch(viewComponentProperties[name], true);
                                }
                        }
                        if (properties.Contains(name))
                                return new ParameterSearch(properties[name], true);
                        if (parent != null)
                                return parent.GetParameterInternal(name);
                        return new ParameterSearch(null, false);
                }

                /// <summary>
                /// Sets the parent.
                /// </summary>
                /// <param name="myParent">My parent.</param>
                public void SetParent(BrailBase myParent)
                {
                        parent = myParent;
                }

                /// <summary>
                /// Allows to check that a parameter was defined
                /// </summary>
                /// <param name="name"></param>
                /// <returns></returns>
                public bool IsDefined(string name)
                {
                        ParameterSearch search = GetParameterInternal(name);
                        return search.Found;
                }

                /// <summary>
                /// Gets the flash.
                /// </summary>
                /// <value>The flash.</value>
                public Flash Flash
                {
                        get { return context.Flash; }
                }

                /// <summary>
                /// Gets the output stream.
                /// </summary>
                /// <value>The output stream.</value>
                public TextWriter OutputStream
                {
                        get { return outputStream; }
                }

                /// <summary>
                /// This is required because we may want to replace the output stream and get the correct
                /// behavior from components call RenderText() or RenderSection()
                /// </summary>
                public IDisposable SetOutputStream(TextWriter newOutputStream)
                {
                        ReturnOutputStreamToInitialWriter disposable = new ReturnOutputStreamToInitialWriter(OutputStream, this);
                        outputStream = newOutputStream;
                        return disposable;
                }

                /// <summary>
                /// Gets or sets the child output.
                /// </summary>
                /// <value>The child output.</value>
                public TextWriter ChildOutput
                {
                        get { return childOutput; }
                        set { childOutput = value; }
                }

                /// <summary>
                /// Gets the properties.
                /// </summary>
                /// <value>The properties.</value>
                public IDictionary Properties
                {
                        get { return properties; }
                }

                /// <summary>
                /// Note that this will overwrite any existing property.
                /// </summary>
                public void AddProperty(string name, object item)
                {
                        properties[name] = item;
                }

                /// <summary>
                /// Adds the view component newProperties.
                /// This will be included in the parameters searching, note that this override
                /// the current parameters if there are clashing.
                /// The search order is LIFO
                /// </summary>
                /// <param name="newProperties">The newProperties.</param>
                public void AddViewComponentProperties(IDictionary newProperties)
                {
                        if (viewComponentsParameters == null)
                                viewComponentsParameters = new ArrayList();
                        viewComponentsParameters.Insert(0, newProperties);
                }

                /// <summary>
                /// Removes the view component properties, so they will no longer be visible to the views.
                /// </summary>
                /// <param name="propertiesToRemove">The properties to remove.</param>
                public void RemoveViewComponentProperties(IDictionary propertiesToRemove)
                {
                        if (viewComponentsParameters == null)
                                return;
                        viewComponentsParameters.Remove(propertiesToRemove);
                }
        public void RenderComponent(string componentName)
        {
            RenderComponent(componentName, new Hashtable());
        }
        public void RenderComponent(string componentName, IDictionary parameters)
        {
            BrailViewComponentContext componentContext =
                new BrailViewComponentContext(this, null, componentName, OutputStream, 
                new Hashtable(StringComparer.InvariantCultureIgnoreCase));
            this.AddViewComponentProperties(componentContext.ComponentParameters);
            IViewComponentFactory componentFactory = (IViewComponentFactory)this.context.GetService(typeof(IViewComponentFactory));
            ViewComponent component = componentFactory.Create(componentName);
            component.Init(this.context, componentContext);
            component.Render();
            if (componentContext.ViewToRender != null)
            {
                this.OutputSubView("/" + componentContext.ViewToRender, componentContext.ComponentParameters);
            }
            this.RemoveViewComponentProperties(componentContext.ComponentParameters);

        }

                /// <summary>
                /// Initialize all the properties that a script may need
                /// One thing to note here is that resources are wrapped in ResourceToDuck wrapper
                /// to enable easy use by the script
                /// </summary>
                /// <param name="myContext"></param>
                /// <param name="myController"></param>
                private void InitProperties(IRailsEngineContext myContext, Controller myController)
                {
                        properties = new Hashtable(
#if DOTNET2
StringComparer.InvariantCultureIgnoreCase
#else
                                CaseInsensitiveHashCodeProvider.Default,
                                CaseInsensitiveComparer.Default
#endif
);
                        properties.Add("Controller", myController);
                        properties.Add("request", myContext.Request);
                        properties.Add("response", myContext.Response);
                        properties.Add("session", myContext.Session);

                        if (myController.Resources != null)
                        {
                                foreach (object key in myController.Resources.Keys)
                                {
                                        properties.Add(key, new ResourceToDuck(myController.Resources[key]));
                                }
                        }

                        foreach (DictionaryEntry entry in myController.Helpers)
                        {
                                properties.Add(entry.Key, entry.Value);
                        }

                        foreach (string key in myController.Params.AllKeys)
                        {
                                if (key == null)
                                        continue;
                                properties[key] = myContext.Params[key];
                        }

                        foreach (DictionaryEntry entry in myContext.Flash)
                        {
                                properties[entry.Key] = entry.Value;
                        }

                        foreach (DictionaryEntry entry in myController.PropertyBag)
                        {
                                properties[entry.Key] = entry.Value;
                        }

                        properties["siteRoot"] = myContext.ApplicationPath;
                }

                private class ParameterSearch
                {
                        private bool found;
                        private object value;

                        public bool Found
                        {
                                get { return found; }
                        }

                        public object Value
                        {
                                get { return value; }
                        }

                        public ParameterSearch(object value, bool found)
                        {
                                this.found = found;
                                this.value = value;
                        }
                }

                private class ReturnOutputStreamToInitialWriter : IDisposable
                {
                        private TextWriter initialWriter;
                        private BrailBase parent;

                        public ReturnOutputStreamToInitialWriter(TextWriter initialWriter, BrailBase parent)
                        {
                                this.initialWriter = initialWriter;
                                this.parent = parent;
                        }

                        public void Dispose()
                        {
                                parent.outputStream = initialWriter;
                        }
                }
        }
}