JavaScript _ javascript tips-js tutorial

This article mainly introduces how JavaScript sorts tables or elements by text, number, or date. It involves the operations and sorting of javascript page elements, for more information about how JavaScript sorts tables or elements by text, number, or date, see the following example. Share it with you for your reference. The specific implementation method is as follows:

// Sorting table columns correctly by text, number or date. There are other // versions, plugins, etc., for this but they either are restricted to specific // date formats, or require EVERY row-element to be given a sort attribute; mine // can handle many different date and number formats, and even allows for specific // cells that may not conform to the overall date/number format for that column. // My version also enables sorting of element hierarchies: such as a DIV containing // P-paragraphs and SPANs - this could even be an image-gallery containing prices // or dates within spans. Very efficient as well!!// Example: andrew.dx.am/sortgallerydel.html// AddSortToTables(); will make the table headers clickable, to sort columns in // ascending or descending order, for any tables with class="sortIt".// SortTable(tbl, col); will sort the table (tbl is an id or table object) by // the supplied column index (indexed from 0) in ascending or descending order.// AddSortByDate(tbl, col, dateMask); enables sorting of a column by date, // specified by a date-mask such as 'dd-mmm-yy'.// AddSortByNumber(tbl, col); enables sorting of a column by number. This assumes a // period . as the decimal separator (if present); it ignores any other non-numeric // characters.// SortElements(parentEl, childTag, colTag, colIndex); will sort (non-table) // elements in ascending or descending order. For example, an UL containing LIs // and SPANs. colIndex specifies which span to sort; there may be more than one in // the LI (0 indexed).// Example: SortElements('pid', 'p', 'span', 2);// 3rd span within each paragraph.//// AddSortByDate2(parentEl, childTag, colTag, colIndex, dateMask); and // AddSortByNumber2(parentEl, childTag, colTag, colIndex)// provide the same feature-set as AddSortByDate and AddSortByNumber does // for tables, but for element hierarchies.// If there are dates or numbers in a column (or element) which don't meet the // date-mask or number formatting necessary to sort correctly, then these inpidual // elements can be given the attribute "sort" and they will still sort correctly!// For example, with a date column  will still sort a // cell correctly. (This format 'YYYY/MM/DD' will be converted into a Date() object.)var MonthNames = ["January", "February", "March", "April", "May", "June", "July",   "August", "September", "October", "November", "December"];var DayNames = [ "Sunday", "Monday", "Tueday", "Wednesday", "Thursday",   "Friday", "Saturday" ];var ShortMths = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug",   "Sep", "Oct", "Nov", "Dec"];var ShortDays = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];var AddEvent = function (elem, eventType, func) {  // Helper function.  if ( elem.addEventListener )    AddEvent = function (elem, eventType, func) {      elem.addEventListener(eventType, func, false);    };  else if ( elem.attachEvent )    AddEvent = function (elem, eventType, func) {      elem.attachEvent('on' + eventType, func);    };  else    AddEvent = function (elem, eventType, func) {      elem['on' + eventType] = func;    };  AddEvent(elem, eventType, func);};// Sort methods/algorithms attributed:var SortTable = function (tbl, col) {  // could be called directly  SortElements(tbl, 'tr', 'td', col);};var SortElements = function (parentEl, childTag, colTag, colIndex) {  // example use: SortElements('table1','tr','td',2)  // or SortElements('list1','li')  // or SortElements('pName','p','span',3)  var i, j, cTags = {}, startAt = 0, childLen, aChild, elem,    sortBy, content, elems = [], sortedLen, frag, hdrsLen, hdr;  var parent = (typeof parentEl === 'string') ?     document.getElementById(parentEl) : parentEl;  var AscText = function (a, b) { // sort() by .data as text    var x = a.data, y = b.data,      xNum = parseFloat(x), yNum = parseFloat(y);      // check if each begin with a number..    if ( !isNaN(xNum) && !isNaN(yNum) && (xNum - yNum) )      return xNum - yNum;    return ((x < y) ? -1 : ((x > y) ? 1 : 0));  };  var DescText = function (a, b) { // sort() by .data    var x = a.data, y = b.data,      xNum = parseFloat(x), yNum = parseFloat(y);      // check if each begin with a number..    if ( !isNaN(xNum) && !isNaN(yNum) && (yNum - xNum) )      return yNum - xNum;    return ((x > y) ? -1 : ((x < y) ? 1 : 0));  };  var AscNum = function (a, b) { // used with dates as well    return a.data - b.data;  };  var DescNum = function (a, b) {    return b.data - a.data;  };  if (parent.nodeName.toLowerCase() == 'table') {    if ( childTag == 'tr' ) {      sortBy = parent.rows[0].cells[colIndex].sortBy || 'text';    }    parent = parent.tBodies[0] || parent;    if ( parent.rows[0].cells[0].nodeName.toLowerCase() == 'th' ) {      startAt = 1;    }  }  cTags = parent.getElementsByTagName(childTag);  if ( typeof colIndex == 'undefined' ) {    sortBy = 'text'; // sort simple lists or paragraphs as text  }  for (i = startAt, childLen = cTags.length; i < childLen; i++) {    // ..go forward examining each child    aChild = cTags[i];    elem = (colTag) ? aChild.getElementsByTagName(colTag)[colIndex] : aChild;    if (elem) {      if ( !sortBy ) { // sorting non-table columns..        sortBy = (typeof elem.numberValue != 'undefined') ? 'number' :           ((typeof elem.dateValue != 'undefined') ? 'date' : 'text');      }      switch (sortBy) {      // You can supply 'sort' attributes to enable sorting of numbers, etc.      // For example,  for a date.        case 'text':          content = (elem.getAttribute('sort') ||             elem.firstChild.nodeValue).toLowerCase();          break;        case 'number':          content = elem.numberValue;          break;        case 'date':          content = elem.dateValue;          break;        default:          content = (elem.getAttribute('sort') ||             elem.firstChild.nodeValue).toLowerCase();          break;      }      j = elems.length;      if ( !aChild.id )         aChild.id = 'tempSortID' + j;      elems[j] = { data: content, tempID: aChild.id };    }  }  // The following will determine if the table/etc has already been sorted   // by the same column or tag. If so, it will sort in ascending or descending   // order. It creates custom element properties to the parent element to   // remember the previous sort details.  if ( typeof colIndex == 'undefined' ) colIndex = 0;  if ( parent.prevTag && parent.prevTag == ((typeof colTag == 'undefined') ?       childTag : colTag) ) {    if (parent.prevCol == colIndex) {      // sorting by the same column as previously      parent.prevSort = (parent.prevSort == 'asc') ? 'desc' : 'asc';    } else { // sorting by any other column      parent.prevCol = colIndex;      parent.prevSort = 'asc';    }  } else {    // sorting for the 1st time or by a different tag    parent.prevTag = ((typeof colTag == 'undefined') ? childTag : colTag);    parent.prevCol = colIndex;    parent.prevSort = 'asc';  }  if ( parent.prevSort === 'desc' ) {    // 'desc' WILL BE the previous sort order..    switch (sortBy) {      case 'text': elems.sort(DescText); break;      case 'number': elems.sort(DescNum); break;      case 'date': elems.sort(DescNum); break;      default: elems.sort(DescText); break;    }  } else {    switch (sortBy) {      case 'text': elems.sort(AscText); break;      case 'number': elems.sort(AscNum); break;      case 'date': elems.sort(AscNum); break;      default: elems.sort(AscText); break;    }  }  frag = document.createDocumentFragment();  for (i = 0, sortedLen = elems.length; i < sortedLen; i++) {    elem = document.getElementById(elems[i].tempID);    frag.appendChild(elem);    if ( (elem.id).substr(0,10) == 'tempSortID' )      elem.removeAttribute('id');  }  parent.appendChild(frag);  elems = null;  return parent.prevSort; // not currently used};var AddSortToTables = function () {  // ..if table has class-name 'sortIt'  var tables = document.getElementsByTagName('table'), i, j,     tblLen, tbl, hdrs, hdrsLen;  function PreserveSortScope(a,b,c,d) {    return function () {      // assign the SortElements fn. to a table header      SortElements(a, b, c, d);    }  }  // add sorting to table headers  for ( i = 0, tblLen = tables.length; i < tblLen; i++ ) {     tbl = tables[i];    if ( tbl.className.indexOf('sortIt') + 1) {      hdrs = tbl.getElementsByTagName('th');      if ( hdrs ) {        for ( j = 0, hdrsLen = hdrs.length; j < hdrsLen; j++ ) {          AddEvent(hdrs[j],'click',PreserveSortScope(tbl,'tr','td',j));          // if there's no title already, add "Click to sort"          if ( !hdrs[j].title ) hdrs[j].setAttribute('title',            'Click to sort');        }      }    }  }};var AddSortByDate = function (tbl, col, dateMask) {  // Input: the table name (or object), a column index (or array)   // and a date mask ('dd-mmm-yy')  // Adds a sortBy = 'date' property to the first row  // will ignore the first row, assuming it is a header row  var i, rLen, cell;  while ( col.length ) AddSortByDate(tbl,col.pop(),dateMask);  if ((col instanceof Array) || isNaN(col)) return;  var tbl = (typeof tbl === 'string') ? document.getElementById(tbl) : tbl;  tbl.rows[0].cells[col].sortBy = 'date';  AddSortByDate2(tbl, 'tr', 'td', col, dateMask);};var AddSortByDate2 = function (parentEl, childTag, colTag, colIndex, dateMask) {  var kids, startAt = 0, i, rLen, cell;  var parent = (typeof parentEl === 'string') ?     document.getElementById(parentEl) : parentEl;  if ( parent.nodeName.toLowerCase() == 'table' ) {    parent = parent.tBodies[0] || parent;    startAt = ( parent.rows[0].cells[0].nodeName.toLowerCase() == 'th' ) * 1;  }  kids = parent.getElementsByTagName(childTag);  for ( i = startAt, rLen = kids.length; i < rLen; i++) {    cell = kids[i].getElementsByTagName(colTag)[colIndex];    if (cell) {      if ( typeof cell.numberValue != 'undefined' ) delete cell.numberValue;      // the above enables switching from a number to a date sort       // (although v. unlikely)      if (cell.getAttribute('sort')) {        // use sort attribute if present        cell.dateValue = new Date(cell.getAttribute('sort'));      } else {        cell.dateValue = new Date(StringToDate(cell.firstChild.nodeValue,           dateMask));      }      if (cell.dateValue.toString() == "NaN" || cell.dateValue.toString() ==           "Invalid Date") {        cell.dateValue = 0;      }     }  }};var AddSortByNumber = function (tbl, col) {  // col is a column index or array of indices  // will ignore the first row, assuming it is a header row  var i, rLen, cell, tempNum;  while ( col.length ) AddSortByNumber(tbl,col.pop());  if ((col instanceof Array) || isNaN(col)) return;  tbl = (typeof tbl === 'string') ? document.getElementById(tbl) : tbl;  tbl.rows[0].cells[col].sortBy = 'number';  AddSortByNumber2(tbl,'tr','td',col);};var AddSortByNumber2 = function (parentEl, childTag, colTag, colIndex) {  var kids, startAt = 0, i, rLen, cell, tempNum;  var parent = (typeof parentEl === 'string') ?     document.getElementById(parentEl) : parentEl;  if ( parent.nodeName.toLowerCase() == 'table' ) {    parent = parent.tBodies[0] || parent;    startAt = (parent.rows[0].cells[0].nodeName.toLowerCase() == 'th') * 1;  }  kids = parent.getElementsByTagName(childTag);  for (i = startAt, rLen = kids.length; i < rLen; i++) {    cell = kids[i].getElementsByTagName(colTag)[colIndex];    if (cell) {      if ( typeof cell.dateValue != 'undefined' ) delete cell.dateValue;      // the above enables switching from a date to a number sort      // (although v. unlikely)      tempNum = cell.getAttribute('sort') || cell.firstChild.nodeValue;      tempNum = tempNum.replace(/[^0-9.-]/g, '');      cell.numberValue = parseFloat(tempNum);      if (isNaN(cell.numberValue))         cell.numberValue = 0.0;    }  }};var StringToDate = function (sDate, sFormat, cutOff) {  // Input: a date value as a string, it's format as a string e.g. 'dd-mmm-yy'  // Optional: a cutoff (integer) for 2 digit years.  // If no 'd' appears in the format string then the 1st of the month is assumed.  // If the year is 20 and the cut-off is 30 then the value will be converted   // to 2020; if the year is 40 then this will be converted to 1940.  // If no cut-off is supplied then '20' will be pre-pended to the year (YY).  // Output: a string in the format 'YYYY/MM/DD' or ''  // Will not attempt to convert certain combinations e.g. DMM, MDD, DDM, YYYYD.  var sParsed, fndSingle;  // sParsed will be constructed in the format 'YYYY/MM/DD'  sDate = sDate.toString().toUpperCase();  sFormat = sFormat.toUpperCase();  if (sFormat.search(/MMMM|MMM/) + 1) { // replace Mar/March with 03, etc.    sDate = sDate.replace(new RegExp('(' + ShortMths.join('|') + ')[A-Z]*', 'gi'),      function (m) {      var i = ShortMths.indexOf(m.charAt(0).toUpperCase() +         m.substr(1, 2).toLowerCase()) + 1;      return ((i < 10) ? "0" + i : "" + i).toString();    });    sFormat = sFormat.replace(/MMMM|MMM/g, 'MM');  }  if (sFormat.search(/DDDD|DDD/) + 1) { // replace Tue/Tuesday, etc. with ''    sDate = sDate.replace(new RegExp('(' + ShortDays.join('|') + ')[A-Z]*', 'gi'),'');    sFormat = sFormat.replace(/DDDD|DDD/g, '');  }  sDate = sDate.replace(/(^|\D)(\d)(?=\D|$)/g, function($0, $1, $2) {    // single digits 2 with 02    return $1 + '0' + $2;  });  sFormat = sFormat.replace(/(^|[^DMY])(D|M)(?=[^DMY]|$)/g, function($0, $1, $2){    return $1 + $2 + $2; // replace D or M with DD and MM  });  // are there still single Ds or Ms?  fndSingle = sFormat.search(/(^|[^D])D([^D]|$)|(^|[^M])M([^M]|$)/)+1;  if ( fndSingle ) return ''; // do not attempt to parse, for example, 'DMM'  sFormat = sFormat.replace(/(^|[^Y])(YY)(?=[^Y]|$)/g, function($0, $1, $2, index) {    var tempDate = sDate.substr(0, index + 1);    tempDate += (cutOff) ? ((parseInt(sDate.substr(index + 1, 2),10) > cutOff) ?       '19' : '20') : '20';    tempDate += sDate.substr(index + 1);    sDate = tempDate;    return $1 + $2 + $2;  });  sParsed = ('YYYY/MM/DD').replace(/YYYY|MM|DD/g, function(m){    return (sFormat.indexOf(m) + 1) ?       sDate.substr(sFormat.indexOf(m), m.length) : '';  });  if (sParsed.charAt(0) == '/') {    // if no year specified, assume the current year    sParsed = (new Date().getFullYear()) + sParsed;  }  if (sParsed.charAt(sParsed.length - 1) == '/') {    // if no date, assume the 1st of the month    sParsed += '01';  }  // should end up with 10 characters..  return ( sParsed.length == 10 ) ? sParsed : '';};

I hope this article will help you design javascript programs.