Added TansuoWsm

Author: sylvainhalle

src/TansuoWsm.js

@@ -0,0 +1,96 @@
+/*
+    WebMole, an automated explorer and tester for Web 2.0 applications
+    Copyright (C) 2012-2013 Gabriel Le Breton, Fabien Maronnaud,
+    Sylvain Hallé et al.
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * Implementation of a Web State Machine using the Tansuo exploration
+ * algorithm that simulates backtracking.
+ * @constructor
+ * @this {TansuoWsm}
+ */
+function TansuoWsm() // extends NoBacktrackWsm {{{
+{
+  // Used to extend the prototype of VanillaWsm
+  this.NoBacktrackWsm = NoBacktrackWsm;
+  this.NoBacktrackWsm();
+  
+  /**
+   * Internal member field to store the ID of the node we want to reach
+   * @type {number}
+   */
+  this.m_targetId = null;
+  
+  /**
+   * Handles the situation where the WSM has reached a dead end and is
+   * sent back to its initial state. See {@link WebStateMachine#processReset}
+   * for detailed info.
+   * <p>
+   * In the case of Tansuo, the procedure
+   * is to return the last suffix that starts with the initial state.
+   * @param {number} The ID of the node in the WSM wher the exploration
+   *   resumes at
+   * @return {boolean} <tt>true</tt> if the exploration must continue,
+   *   <tt>false</tt> if there is no unvisited page
+   */
+  this.processReset = function(node_id) // {{{
+  {
+    // Pop last state in the state stack and peek next-to-last
+    if (this.m_pathSinceBeginning.getLength() === 0)
+    {
+      // Not supposed to happen, but anyway, means we are done
+      return false;
+    }
+    var dummy = this.m_pathSinceBeginning.popLastElement();
+    if (this.m_pathSinceBeginning.getLength() === 0)
+    {
+      // Finished backtracking: we are done
+      return false;
+    }
+    // If no ID is passed, we assume we reset the application, i.e.
+    // go back to its initial state (the one with ID=1)
+    if (node_id === undefined)
+    {
+      node_id = 1;
+    }
+    var len = this.m_pathSinceBeginning.getLength();
+    for (var i = len - 1; i >= 0; i--)
+    {
+      // Go backwards until we find the initial state
+      var pseg = this.m_pathSinceBeginning.getElement(i);
+      var dest_id = pseg.getDestination();
+      if (dest_id == node_id)
+      {
+        // We found it
+        break;
+      }
+    }
+    // Assert: i = position of last occurrence of node_id in sequence
+    // Path to follow = suffix of sequence from that position
+    var out_ps = new PathSequence();
+    for (var j = i; j < len; j++)
+    {
+      var segment = this.m_pathSinceBeginning.getElement(j);
+      out_ps.append(segment);
+    }
+    this.m_pathToFollow = out_ps;
+    return true;
+  }; // }}}
+  
+} // }}}
+
+/* :folding=explicit:wrap=none: */

src/Wsm.js

@@ -416,6 +416,21 @@ function PathSequence(ps) // {{{
     this.m_elements.push(path_element);
   }; // }}}
 
+  /**
+   * Returns the <i>i</i>-th element of the path sequence
+   * @param {number} The position of the element to look for
+   * @return The first element
+   */
+  this.getElement = function(i) // {{{
+  {
+    if (i >= this.m_elements.length || i < 0)
+    {
+      console.error("Calling getElement outside of valid range");
+      return;
+    }
+    return this.m_elements[i];
+  }; // }}}
+  
   /**
    * Returns the first element of the path sequence and removes it
    * from the sequence