added xmlids to all of the code blocks from 8.1-8.4

Author: coco3427

source/ch8_filehandling.ptx

@@ -192,7 +192,7 @@
             </datafile>
 
 
-        <program interactive="activecode"  language="java" add-files= "my-file">
+        <program xml:id="file-read-exp1" interactive="activecode"  language="java" add-files= "my-file">
             <code>
             import java.io.File;
             import java.io.FileNotFoundException;
@@ -220,7 +220,7 @@
             We will then create a new File object exactly the same as the one from the section on creating files. Additionally, we will create a Scanner object. The Scanner object is the object that does the file reading. We will call this scanner fileReader:
         </p>
 
-        <program interactive="activecode" language="java">
+        <program xml:id="file-read-exp2" interactive="activecode" language="java">
             <code>
             import java.io.File;
             import java.io.FileNotFoundException;
@@ -248,7 +248,7 @@
             The next lines consists of a Python code example that reads each line of the file passed to the Scanner object.:
         </p>
 
-        <program interactive="activecode" language="python" add-files="my-file">
+        <program xml:id="file-read-exp3" interactive="activecode" language="python" add-files="my-file">
             <code>
                 with open("myfile.txt", "r") as file_reader:
                     for line in file_reader:
@@ -260,7 +260,7 @@
             The equivalent Java code:
         </p>
 
-        <program interactive="activecode"  language="java" add-files= "my-file">
+        <program xml:id="file-read-exp4" interactive="activecode"  language="java" add-files= "my-file">
             <code>
             import java.io.File;
             import java.io.FileNotFoundException;
@@ -289,7 +289,7 @@
             Alternatively, the following code can be used to store the all lines of myfile.txt to one variable:
         </p>
 
-        <program interactive="activecode" language="java" add-files="my-file">
+        <program xml:id="file-read-exp5" interactive="activecode" language="java" add-files="my-file">
             <code>
             import java.io.File;
             import java.io.FileNotFoundException;
@@ -321,7 +321,7 @@
             Using the second method of storing all file contents to one file, the resulting full code including try/catch blocks (this time using FileNotFoundException instead of IOException) will look something like this. First, the Python code:
         </p>
 
-        <program interactive="activecode" language="python">
+        <program xml:id="file-read-exp6" interactive="activecode" language="python">
             <code>
                 try:
                     with open("myfile.txt", "r") as file_reader:
@@ -341,7 +341,7 @@
             And the Java equivalent:
         </p>
 
-        <program interactive="activecode" language="java" add-files="my-file">
+        <program xml:id="file-read-exp7" interactive="activecode" language="java" add-files="my-file">
             <code>
             import java.io.File;
             import java.io.FileNotFoundException;
@@ -382,7 +382,7 @@
             Let us create the framework for a class that will write to a file. Let's call this class <c>WriteFile</c>:
         </p>
 
-        <program interactive="activecode" language="java">
+        <program xml:id="file-write-exp1" interactive="activecode" language="java">
             <code>
             import java.io.File;
             import java.io.FileWriter;
@@ -444,7 +444,7 @@
                     3
                 </pre>
             </datafile>
-        <program interactive="activecode" language="python" add-files = "my-file-8-4-2">
+        <program xml:id="file-write-exp2" interactive="activecode" language="python" add-files = "my-file-8-4-2">
             <code>
                 with open("myfile8-4-2.txt", "r") as file_reader:
                     while True:
@@ -463,7 +463,7 @@
 
                 </pre>
             </datafile>
-        <program interactive="activecode" language="java" add-files = "my-file-8-4-3">
+        <program xml:id="file-write-exp3" interactive="activecode" language="java" add-files = "my-file-8-4-3">
             <code>
             import java.io.File;
             import java.io.IOException;
@@ -491,7 +491,7 @@
 
                 </pre>
             </datafile>
-        <program interactive="activecode" language="python" add-files = "my-file-8-4-4">
+        <program xml:id="file-write-exp4" interactive="activecode" language="python" add-files = "my-file-8-4-4">
             <code>
             try:
                 with open("myfile.txt", "w") as my_writer:
@@ -512,7 +512,7 @@
 
                 </pre>
             </datafile>
-        <program interactive="activecode" language="java" add-files = "my-file-8-4-5">
+        <program xml:id="file-write-exp5" interactive="activecode" language="java" add-files = "my-file-8-4-5">
             <code>
             import java.io.FileWriter;
             import java.io.IOException;
@@ -559,7 +559,7 @@
 
                 </pre>
             </datafile>
-        <program interactive="activecode" language="java" add-files = "my-file-8-4-6">
+        <program xml:id="file-write-exp6" interactive="activecode" language="java" add-files = "my-file-8-4-6">
             <code>
             import java.io.FileWriter;
             import java.io.IOException;