1 files changed, 140 insertions, 0 deletions
diff --git a/lib/webcals/ics.js b/lib/webcals/ics.js
new file mode 100644
index 0000000..2397239
--- /dev/null
+++ b/lib/webcals/ics.js
@@ -0,0 +1,140 @@
+/**
+@namespace
+*/
+(function(module, ns) {
+
+  // Iterate over all entries if x is an array, otherwise just call fn on x.
+  function ForAll(x, fn) {
+    if (!(x instanceof Array)) {
+      fn(x);
+      return;
+    }
+    for (var n = 0; n < x.length; ++n)
+      fn(x[n]);
+  }
+
+  /* Pattern for an individual entry: name:value */
+  var ENTRY = /^([A-Za-z0-9-]+)((?:;[A-Za-z0-9-]+=(?:"[^"]+"|[^";:,]+)(?:,(?:"[^"]+"|[^";:,]+))*)*):(.*)$/;
+  /* Pattern for an individual parameter: name=value[,value] */
+  var PARAM = /;([A-Za-z0-9-]+)=((?:"[^"]+"|[^";:,]+)(?:,(?:"[^"]+"|[^";:,]+))*)/g;
+  /* Pattern for an individual parameter value: value | "value" */
+  var PARAM_VALUE = /,?("[^"]+"|[^";:,]+)/g;
+
+  // Parse a calendar in iCal format.
+  function ParseICal (text, success, error) {
+    // Parse the text into an object graph
+    var lines = text.replace('\r', '').split('\n');
+    var tos = Object.create(null);
+    var stack = [tos];
+
+    // Parse parameters for an entry. Foramt: <param>=<pvalue>[;...]
+    function parseParams(params) {
+      var map = Object.create(null);
+      var param = PARAM.exec(params);
+      while (param) {
+        var values = [];
+        var value = PARAM_VALUE.exec(param[2]);
+        while (value) {
+          values.push(value[1].replace(/^"(.*)"$/, '$1'));
+          value = PARAM_VALUE.exec(param[2]);
+        }
+        map[param[1].toLowerCase()] = (values.length > 1 ? values : values[0]);
+        param = PARAM.exec(params);
+      }
+      return map;
+    }
+
+    // Add a property to the current object. If a property with the same name
+    // already exists, turn it into an array.
+    function add(prop, value, params) {
+      if (params)
+        value = { parameters: parseParams(params), value: value };
+      if (prop in tos) {
+        var previous = tos[prop];
+        if (previous instanceof Array) {
+          previous.push(value);
+          return;
+        }
+        value = [previous, value];
+      }
+      tos[prop] = value;
+    }
+
+    for (var n = 0; n < lines.length; ++n) {
+      var line = lines[n];
+      // check whether the line continues (next line stats with space or tab)
+      var nextLine;
+      while ((nextLine = lines[n+1]) && (nextLine[0] == ' ' || nextLine[0] == '\t')) {
+        line += nextLine.substr(1);
+        ++n;
+        continue;
+      }
+      // parse the entry, format is 'PROPERTY:VALUE'
+      var matches = ENTRY.exec(line);
+      if (!matches)
+        return error('invalid format');
+      var prop = matches[1].toLowerCase();
+      var params = matches[2];
+      var value = matches[3];
+      switch (prop) {
+      case 'begin':
+        var obj = Object.create(null);
+        add(value.toLowerCase(), obj);
+        stack.push(tos = obj);
+        break;
+      case 'end':
+        stack.pop();
+        tos = stack[stack.length - 1];
+        if (stack.length == 1) {
+          var cal = stack[0];
+          if (typeof cal.vcalendar != 'object' || cal.vcalendar instanceof Array)
+            return error('single vcalendar object expected');
+          return success(cal.vcalendar);
+        }
+        break;
+      default:
+        add(prop, value, params);
+        break;
+      }
+    }
+    return error('unexpected end of file');
+  }
+
+  function Value(v) {
+    return (typeof v !== 'object') ? v : v.value;
+  }
+
+  function Parameter(v, name) {
+    if (typeof v !== 'object')
+      return undefined;
+    return v.parameters[name];
+  }
+
+  // Parse a time specification.
+  function ParseDateTime(v) {
+    var dt = Value(v);
+    if (Parameter(v, 'VALUE') == 'DATE') {
+      // 20081202
+      return new Date(dt.substr(0, 4), dt.substr(4, 2), dt.substr(6, 2));
+    }
+    v = Value(v);
+    // 20120426T130000Z
+    var year = dt.substr(0, 4);
+    var month = dt.substr(4, 2) - 1;
+    var day = dt.substr(6, 2);
+    var hour = dt.substr(9, 2);
+    var min = dt.substr(11, 2);
+    var sec = dt.substr(13, 2);
+    if (dt[15] == 'Z')
+      return new Date(Date.UTC(year, month, day, hour, min, sec));
+    return new Date(year, month, day, hour, min, sec);
+  }
+
+  module.exports = ParseICal;
+
+}.apply(
+  this,
+  (this.CalDav) ?
+    [CalDav('ics'), CalDav] :
+    [module, require('./webcals')]
+));