From 995a0534006e27d6066a485c46e09661f6673d87 Mon Sep 17 00:00:00 2001
From: Rufus Pollock <rufus.pollock@okfn.org>
Date: Tue, 27 Mar 2012 08:27:10 +0100
Subject: [PATCH] [#36,backend/localcsv][s]: start on local 'backend' with CSV
 parser and test.

---
 src/backend/localcsv.js       | 145 ++++++++++++++++++++++++++++++++++
 test/backend.localcsv.test.js |  24 ++++++
 2 files changed, 169 insertions(+)
 create mode 100644 src/backend/localcsv.js
 create mode 100644 test/backend.localcsv.test.js

diff --git a/src/backend/localcsv.js b/src/backend/localcsv.js
new file mode 100644
index 00000000..7efb9a28
--- /dev/null
+++ b/src/backend/localcsv.js
@@ -0,0 +1,145 @@
+this.recline = this.recline || {};
+this.recline.Backend = this.recline.Backend || {};
+
+(function($, my) {
+  my.loadFromCSVFile = function(file) {
+    var metadata = {
+      id: file.name,
+      file: file
+    };
+    var reader = new FileReader();
+    // TODO
+    reader.onload = function(e) {
+      // console.log(e.target.result);
+    };
+    reader.onerror = function (e) {
+      alert('Failed to load file. Code: ' + e.target.error.code);
+    }
+    reader.readAsText(file);
+  };
+
+	// Converts a Comma Separated Values string into an array of arrays.
+	// Each line in the CSV becomes an array.
+  //
+	// Empty fields are converted to nulls and non-quoted numbers are converted to integers or floats.
+  //
+	// @return The CSV parsed as an array
+	// @type Array
+	// 
+	// @param {String} s The string to convert
+	// @param {Boolean} [trm=false] If set to True leading and trailing whitespace is stripped off of each non-quoted field as it is imported
+  //
+  // Heavily based on uselesscode's JS CSV parser (MIT Licensed):
+  // thttp://www.uselesscode.org/javascript/csv/
+	my.parseCSV= function(s, trm) {
+		// Get rid of any trailing \n
+		s = chomp(s);
+
+		var cur = '', // The character we are currently processing.
+			inQuote = false,
+			fieldQuoted = false,
+			field = '', // Buffer for building up the current field
+			row = [],
+			out = [],
+			i,
+			processField;
+
+		processField = function (field) {
+			if (fieldQuoted !== true) {
+				// If field is empty set to null
+				if (field === '') {
+					field = null;
+				// If the field was not quoted and we are trimming fields, trim it
+				} else if (trm === true) {
+					field = trim(field);
+				}
+
+				// Convert unquoted numbers to their appropriate types
+				if (rxIsInt.test(field)) {
+					field = parseInt(field, 10);
+				} else if (rxIsFloat.test(field)) {
+					field = parseFloat(field, 10);
+				}
+			}
+			return field;
+		};
+
+		for (i = 0; i < s.length; i += 1) {
+			cur = s.charAt(i);
+
+			// If we are at a EOF or EOR
+			if (inQuote === false && (cur === ',' || cur === "\n")) {
+				field = processField(field);
+				// Add the current field to the current row
+				row.push(field);
+				// If this is EOR append row to output and flush row
+				if (cur === "\n") {
+					out.push(row);
+					row = [];
+				}
+				// Flush the field buffer
+				field = '';
+				fieldQuoted = false;
+			} else {
+				// If it's not a ", add it to the field buffer
+				if (cur !== '"') {
+					field += cur;
+				} else {
+					if (!inQuote) {
+						// We are not in a quote, start a quote
+						inQuote = true;
+						fieldQuoted = true;
+					} else {
+						// Next char is ", this is an escaped "
+						if (s.charAt(i + 1) === '"') {
+							field += '"';
+							// Skip the next char
+							i += 1;
+						} else {
+							// It's not escaping, so end quote
+							inQuote = false;
+						}
+					}
+				}
+			}
+		}
+
+		// Add the last field
+		field = processField(field);
+		row.push(field);
+		out.push(row);
+
+		return out;
+	};
+
+	var rxIsInt = /^\d+$/,
+		rxIsFloat = /^\d*\.\d+$|^\d+\.\d*$/,
+		// If a string has leading or trailing space,
+		// contains a comma double quote or a newline
+		// it needs to be quoted in CSV output
+		rxNeedsQuoting = /^\s|\s$|,|"|\n/,
+		trim = (function () {
+			// Fx 3.1 has a native trim function, it's about 10x faster, use it if it exists
+			if (String.prototype.trim) {
+				return function (s) {
+					return s.trim();
+				};
+			} else {
+				return function (s) {
+					return s.replace(/^\s*/, '').replace(/\s*$/, '');
+				};
+			}
+		}());
+
+	function chomp(s) {
+		if (s.charAt(s.length - 1) !== "\n") {
+			// Does not end with \n, just return string
+			return s;
+		} else {
+			// Remove the \n
+			return s.substring(0, s.length - 1);
+		}
+	}
+
+
+}(jQuery, this.recline.Backend));
diff --git a/test/backend.localcsv.test.js b/test/backend.localcsv.test.js
new file mode 100644
index 00000000..c37fc138
--- /dev/null
+++ b/test/backend.localcsv.test.js
@@ -0,0 +1,24 @@
+(function ($) {
+module("Backend Local CSV");
+
+test("parseCSV", function() { 
+  var csv = '"Jones, Jay",10\n' +
+  '"Xyz ""ABC"" O\'Brien",11:35\n' +
+  '"Other, AN",12:35\n';
+
+  var array = recline.Backend.parseCSV(csv);
+  var exp = [
+    ['Jones, Jay', 10],
+    ['Xyz "ABC" O\'Brien', '11:35' ],
+    ['Other, AN', '12:35' ]
+  ];
+  deepEqual(exp, array);
+
+  var csv = '"Jones, Jay", 10\n' +
+  '"Xyz ""ABC"" O\'Brien", 11:35\n' +
+  '"Other, AN", 12:35\n';
+  var array = recline.Backend.parseCSV(csv, true);
+  deepEqual(exp, array);
+});
+
+})(this.jQuery);