Initial project's source code check-in.

WebsitePanel/Sources/WebsitePanel.Templates/Template.cs

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+// Copyright (c) 2011, Outercurve Foundation.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification,
+// are permitted provided that the following conditions are met:
+//
+// - Redistributions of source code must  retain  the  above copyright notice, this
+//   list of conditions and the following disclaimer.
+//
+// - Redistributions in binary form  must  reproduce the  above  copyright  notice,
+//   this list of conditions  and  the  following  disclaimer in  the documentation
+//   and/or other materials provided with the distribution.
+//
+// - Neither  the  name  of  the  Outercurve Foundation  nor   the   names  of  its
+//   contributors may be used to endorse or  promote  products  derived  from  this
+//   software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,  BUT  NOT  LIMITED TO, THE IMPLIED
+// WARRANTIES  OF  MERCHANTABILITY   AND  FITNESS  FOR  A  PARTICULAR  PURPOSE  ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL,  SPECIAL,  EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO,  PROCUREMENT  OF  SUBSTITUTE  GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)  HOWEVER  CAUSED AND ON
+// ANY  THEORY  OF  LIABILITY,  WHETHER  IN  CONTRACT,  STRICT  LIABILITY,  OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE)  ARISING  IN  ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+using System;
+using System.IO;
+using System.Collections.Generic;
+using System.Text;
+using WebsitePanel.Templates.AST;
+using System.Collections;
+
+namespace WebsitePanel.Templates
+{
+    /// <summary>
+    /// Template allows to process block of texts containing special directives such as variables,
+    /// conditional statements and loops.
+    /// </summary>
+    public class Template
+    {
+        string data;
+        Lexer lexer = null;
+        Parser parser = null;
+        List<AST.Statement> statements = null;
+        TemplateContext context = new TemplateContext();
+
+        /// <summary>
+        /// Initializes a new instance of Template with specified template text.
+        /// </summary>
+        /// <param name="data">Template text.</param>
+        public Template(string data)
+        {
+            if (data == null)
+                throw new ArgumentNullException("data");
+
+            this.data = data;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of Template with specified StringReader containing template text.
+        /// </summary>
+        /// <param name="reader">StringReader containing template text.</param>
+        public Template(StringReader reader)
+        {
+            if(reader == null)
+                throw new ArgumentNullException("reader");
+
+            this.data = reader.ReadToEnd();
+        }
+
+        /// <summary>
+        /// Verifies template syntax and throws <see cref="ParserException">ParserException</see> when error is found.
+        /// </summary>
+        /// <exception cref="ParserException">Thrown when error is found.</exception>
+        public void CheckSyntax()
+        {
+            // create lexer
+            lexer = new Lexer(data);
+
+            // create parser
+            parser = new Parser(lexer);
+
+            // parse template
+            parser.Parse();
+        }
+
+        /// <summary>
+        /// Evaluates template and returns the result as a string.
+        /// </summary>
+        /// <returns>String containing evaluated template.</returns>
+        public string Evaluate()
+        {
+            // create writer to hold result
+            StringWriter writer = new StringWriter();
+
+            // evaluate
+            Evaluate(writer);
+
+            // return result
+            return writer.ToString();
+        }
+
+        /// <summary>
+		/// Evaluates template and returns the result as a string.
+		/// </summary>
+		/// <returns>String containing evaluated template.</returns>
+		public string Evaluate(Hashtable items)
+		{
+			// copy items from hashtable
+			foreach (string keyName in items.Keys)
+			{
+				this[keyName] = items[keyName];
+			}
+
+			// evaluate
+			return Evaluate();
+		}
+
+		/// <summary>
+		/// Evaluates template to the StringWriter.
+        /// </summary>
+        /// <param name="writer">StringWriter to write evaluation results.</param>
+        public void Evaluate(StringWriter writer)
+        {
+            if(writer == null)
+                throw new ArgumentNullException("writer");
+
+            if (lexer == null)
+            {
+                // create lexer
+                lexer = new Lexer(data);
+
+                // create parser
+                parser = new Parser(lexer);
+
+                // parse template
+                statements = parser.Parse();
+            }
+
+            // index custom templates
+            int i = 0;
+            while (i < statements.Count)
+            {
+                TemplateStatement tmpStatement = statements[i] as TemplateStatement;
+                if (tmpStatement != null)
+                {
+                    context.Templates.Add(tmpStatement.Name, tmpStatement);
+                    statements.RemoveAt(i);
+                    continue;
+                }
+                i++;
+            }
+
+            // evaluate template statements
+            foreach (AST.Statement stm in statements)
+            {
+                // eval next statement
+                stm.Eval(context, writer);
+            }
+        }
+
+        /// <summary>
+        /// Gets or sets the value of template context variable.
+        /// </summary>
+        /// <param name="name">The name of the context variable. Variable names are case-insensitive.</param>
+        /// <returns>Returns the value of the context variable.</returns>
+        public object this[string name]
+        {
+            get { return context.Variables.ContainsKey(name) ? context.Variables[name] : null; }
+            set { context.Variables[name] = value; }
+        }
+    }
+}