From fadd7158ed4cd79c1a3800ff1a4973bee8a4f4c7 Mon Sep 17 00:00:00 2001
From: Dale Myers <dalemy@microsoft.com>
Date: Mon, 23 Jan 2017 21:39:08 +0000
Subject: [PATCH] Add string escape/unescape operations

These operations are useful for taking the contents of a string, and making it
suitable for use as a stand alone string. For example, in an IDE you might see
a string which is represented as: "Say \"Hello\"". The escaped double quotes
are shown to make it clear that they do not end the string, despite the fact
that they are not truly part of the string. In order to get the raw string, you
would need to copy this, then manually remove the backslashes. The new
String_.run_unescape operation does this automatically.

The String_.run_escape is the inverse. It allows you to take a string like the
one above, and paste it between two quotes without having to manually escape
it.
---
 src/js/config/Categories.js      |  2 +
 src/js/config/OperationConfig.js | 16 +++++++-
 src/js/operations/String.js      | 67 ++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100755 src/js/operations/String.js

diff --git a/src/js/config/Categories.js b/src/js/config/Categories.js
index db43721c..d7ad1407 100755
--- a/src/js/config/Categories.js
+++ b/src/js/config/Categories.js
@@ -167,6 +167,8 @@ var Categories = [
             "Parse UNIX file permissions",
             "Swap endianness",
             "Parse colour code",
+            "Escape String",
+            "Unescape String",
         ]
     },
     {
diff --git a/src/js/config/OperationConfig.js b/src/js/config/OperationConfig.js
index b5ea0427..cbed494f 100755
--- a/src/js/config/OperationConfig.js
+++ b/src/js/config/OperationConfig.js
@@ -2952,5 +2952,19 @@ var OperationConfig = {
                 value: Cipher.SUBS_CIPHERTEXT
             }
         ]
-    }
+    },
+    "Escape String": {
+        description: "Escapes a string so that it can be embedded in another. For example, <code>Don't stop me now</code> becomes <code>Don\\'t stop me now</code>.",
+        run: String_.run_escape,
+        input_type: "string",
+        output_type: "string",
+        args: []
+    },
+    "Unescape String": {
+        description: "Unescapes a string that was embedded inside another so that it can be used in it's own right. For example, <code>Don\\'t stop me now</code> becomes <code>Don't stop me now</code>.",
+        run: String_.run_unescape,
+        input_type: "string",
+        output_type: "string",
+        args: []
+    },
 };
diff --git a/src/js/operations/String.js b/src/js/operations/String.js
new file mode 100755
index 00000000..a85b385b
--- /dev/null
+++ b/src/js/operations/String.js
@@ -0,0 +1,67 @@
+/**
+ * String operations.
+ * Namespace is appended with an underscore to prevent overwriting the global String object.
+ *
+ * @author Vel0x
+ * @namespace
+ */
+var String_ = {
+
+    /**
+     * @constant
+     * @default
+     */
+    REPLACEMENTS: [
+        {"escaped": "\\\\", "unescaped":"\\"}, // Must be first
+        {"escaped": "\\'", "unescaped":"'"},
+        {"escaped": "\\\"", "unescaped":"\""},
+        {"escaped": "\\n", "unescaped":"\n"},
+        {"escaped": "\\r", "unescaped":"\r"},
+    ],
+    
+    /**
+     * Escapes a string for embedding in another string.
+     *
+     * Example: "Don't do that" -> "Don\'t do that"
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run_escape: function(input, args) {
+        return String_._replace_by_keys(input, "unescaped", "escaped")
+    },
+    
+    /**
+     * Unescapes a string that was part of another string
+     *
+     * Example: "Don\'t do that" -> "Don't do that"
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run_unescape: function(input, args) {
+        return String_._replace_by_keys(input, "escaped", "unescaped")
+    },
+    
+    /**
+     * Replaces all matching tokens in REPLACEMENTS with the correction. The 
+     * ordering is determined by the pattern_key and the replacement_key.
+     *
+     * @param {string} input
+     * @param {string} pattern_key
+     * @param {string} replacement_key
+     * @returns {string}
+     */
+    _replace_by_keys: function(input, pattern_key, replacement_key) {
+        var output = input;
+        var replacementsLength = String_.REPLACEMENTS.length;
+        for (var i = 0; i < replacementsLength; i++) {
+            var replacement = String_.REPLACEMENTS[i];
+            output = output.split(replacement[pattern_key]).join(replacement[replacement_key]);
+        }
+        return output
+    },
+    
+};