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1 /* 'Magic' date parsing, by Simon Willison (6th October 2003) |
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2 http://simon.incutio.com/archive/2003/10/06/betterDateInput |
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3 Adapted for 6newslawrence.com, 28th January 2004 |
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4 */ |
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5 |
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6 /* Finds the index of the first occurence of item in the array, or -1 if not found */ |
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7 if (typeof Array.prototype.indexOf == 'undefined') { |
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8 Array.prototype.indexOf = function(item) { |
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9 var len = this.length; |
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10 for (var i = 0; i < len; i++) { |
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11 if (this[i] == item) { |
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12 return i; |
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13 } |
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14 } |
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15 return -1; |
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16 }; |
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17 } |
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18 /* Returns an array of items judged 'true' by the passed in test function */ |
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19 if (typeof Array.prototype.filter == 'undefined') { |
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20 Array.prototype.filter = function(test) { |
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21 var matches = []; |
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22 var len = this.length; |
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23 for (var i = 0; i < len; i++) { |
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24 if (test(this[i])) { |
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25 matches[matches.length] = this[i]; |
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26 } |
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27 } |
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28 return matches; |
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29 }; |
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30 } |
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31 |
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32 var monthNames = gettext("January February March April May June July August September October November December").split(" "); |
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33 var weekdayNames = gettext("Sunday Monday Tuesday Wednesday Thursday Friday Saturday").split(" "); |
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34 |
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35 /* Takes a string, returns the index of the month matching that string, throws |
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36 an error if 0 or more than 1 matches |
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37 */ |
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38 function parseMonth(month) { |
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39 var matches = monthNames.filter(function(item) { |
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40 return new RegExp("^" + month, "i").test(item); |
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41 }); |
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42 if (matches.length == 0) { |
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43 throw new Error("Invalid month string"); |
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44 } |
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45 if (matches.length > 1) { |
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46 throw new Error("Ambiguous month"); |
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47 } |
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48 return monthNames.indexOf(matches[0]); |
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49 } |
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50 /* Same as parseMonth but for days of the week */ |
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51 function parseWeekday(weekday) { |
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52 var matches = weekdayNames.filter(function(item) { |
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53 return new RegExp("^" + weekday, "i").test(item); |
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54 }); |
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55 if (matches.length == 0) { |
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56 throw new Error("Invalid day string"); |
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57 } |
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58 if (matches.length > 1) { |
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59 throw new Error("Ambiguous weekday"); |
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60 } |
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61 return weekdayNames.indexOf(matches[0]); |
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62 } |
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63 |
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64 /* Array of objects, each has 're', a regular expression and 'handler', a |
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65 function for creating a date from something that matches the regular |
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66 expression. Handlers may throw errors if string is unparseable. |
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67 */ |
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68 var dateParsePatterns = [ |
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69 // Today |
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70 { re: /^tod/i, |
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71 handler: function() { |
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72 return new Date(); |
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73 } |
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74 }, |
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75 // Tomorrow |
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76 { re: /^tom/i, |
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77 handler: function() { |
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78 var d = new Date(); |
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79 d.setDate(d.getDate() + 1); |
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80 return d; |
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81 } |
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82 }, |
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83 // Yesterday |
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84 { re: /^yes/i, |
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85 handler: function() { |
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86 var d = new Date(); |
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87 d.setDate(d.getDate() - 1); |
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88 return d; |
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89 } |
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90 }, |
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91 // 4th |
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92 { re: /^(\d{1,2})(st|nd|rd|th)?$/i, |
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93 handler: function(bits) { |
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94 var d = new Date(); |
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95 d.setDate(parseInt(bits[1], 10)); |
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96 return d; |
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97 } |
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98 }, |
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99 // 4th Jan |
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100 { re: /^(\d{1,2})(?:st|nd|rd|th)? (\w+)$/i, |
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101 handler: function(bits) { |
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102 var d = new Date(); |
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103 d.setDate(parseInt(bits[1], 10)); |
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104 d.setMonth(parseMonth(bits[2])); |
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105 return d; |
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106 } |
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107 }, |
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108 // 4th Jan 2003 |
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109 { re: /^(\d{1,2})(?:st|nd|rd|th)? (\w+),? (\d{4})$/i, |
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110 handler: function(bits) { |
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111 var d = new Date(); |
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112 d.setDate(parseInt(bits[1], 10)); |
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113 d.setMonth(parseMonth(bits[2])); |
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114 d.setYear(bits[3]); |
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115 return d; |
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116 } |
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117 }, |
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118 // Jan 4th |
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119 { re: /^(\w+) (\d{1,2})(?:st|nd|rd|th)?$/i, |
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120 handler: function(bits) { |
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121 var d = new Date(); |
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122 d.setDate(parseInt(bits[2], 10)); |
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123 d.setMonth(parseMonth(bits[1])); |
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124 return d; |
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125 } |
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126 }, |
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127 // Jan 4th 2003 |
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128 { re: /^(\w+) (\d{1,2})(?:st|nd|rd|th)?,? (\d{4})$/i, |
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129 handler: function(bits) { |
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130 var d = new Date(); |
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131 d.setDate(parseInt(bits[2], 10)); |
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132 d.setMonth(parseMonth(bits[1])); |
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133 d.setYear(bits[3]); |
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134 return d; |
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135 } |
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136 }, |
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137 // next Tuesday - this is suspect due to weird meaning of "next" |
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138 { re: /^next (\w+)$/i, |
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139 handler: function(bits) { |
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140 var d = new Date(); |
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141 var day = d.getDay(); |
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142 var newDay = parseWeekday(bits[1]); |
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143 var addDays = newDay - day; |
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144 if (newDay <= day) { |
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145 addDays += 7; |
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146 } |
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147 d.setDate(d.getDate() + addDays); |
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148 return d; |
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149 } |
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150 }, |
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151 // last Tuesday |
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152 { re: /^last (\w+)$/i, |
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153 handler: function(bits) { |
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154 throw new Error("Not yet implemented"); |
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155 } |
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156 }, |
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157 // mm/dd/yyyy (American style) |
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158 { re: /(\d{1,2})\/(\d{1,2})\/(\d{4})/, |
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159 handler: function(bits) { |
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160 var d = new Date(); |
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161 d.setYear(bits[3]); |
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162 d.setDate(parseInt(bits[2], 10)); |
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163 d.setMonth(parseInt(bits[1], 10) - 1); // Because months indexed from 0 |
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164 return d; |
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165 } |
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166 }, |
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167 // yyyy-mm-dd (ISO style) |
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168 { re: /(\d{4})-(\d{1,2})-(\d{1,2})/, |
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169 handler: function(bits) { |
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170 var d = new Date(); |
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171 d.setYear(parseInt(bits[1])); |
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172 d.setMonth(parseInt(bits[2], 10) - 1); |
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173 d.setDate(parseInt(bits[3], 10)); |
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174 return d; |
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175 } |
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176 }, |
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177 ]; |
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178 |
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179 function parseDateString(s) { |
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180 for (var i = 0; i < dateParsePatterns.length; i++) { |
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181 var re = dateParsePatterns[i].re; |
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182 var handler = dateParsePatterns[i].handler; |
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183 var bits = re.exec(s); |
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184 if (bits) { |
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185 return handler(bits); |
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186 } |
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187 } |
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188 throw new Error("Invalid date string"); |
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189 } |
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190 |
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191 function fmt00(x) { |
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192 // fmt00: Tags leading zero onto numbers 0 - 9. |
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193 // Particularly useful for displaying results from Date methods. |
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194 // |
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195 if (Math.abs(parseInt(x)) < 10){ |
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196 x = "0"+ Math.abs(x); |
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197 } |
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198 return x; |
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199 } |
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200 |
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201 function parseDateStringISO(s) { |
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202 try { |
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203 var d = parseDateString(s); |
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204 return d.getFullYear() + '-' + (fmt00(d.getMonth() + 1)) + '-' + fmt00(d.getDate()) |
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205 } |
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206 catch (e) { return s; } |
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207 } |
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208 function magicDate(input) { |
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209 var messagespan = input.id + 'Msg'; |
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210 try { |
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211 var d = parseDateString(input.value); |
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212 input.value = d.getFullYear() + '-' + (fmt00(d.getMonth() + 1)) + '-' + |
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213 fmt00(d.getDate()); |
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214 input.className = ''; |
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215 // Human readable date |
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216 if (document.getElementById(messagespan)) { |
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217 document.getElementById(messagespan).firstChild.nodeValue = d.toDateString(); |
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218 document.getElementById(messagespan).className = 'normal'; |
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219 } |
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220 } |
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221 catch (e) { |
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222 input.className = 'error'; |
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223 var message = e.message; |
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224 // Fix for IE6 bug |
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225 if (message.indexOf('is null or not an object') > -1) { |
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226 message = 'Invalid date string'; |
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227 } |
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228 if (document.getElementById(messagespan)) { |
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229 document.getElementById(messagespan).firstChild.nodeValue = message; |
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230 document.getElementById(messagespan).className = 'error'; |
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231 } |
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232 } |
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233 } |