Cheatsheets

Here are links to various cheatsheets:

http://www.webappers.com/2008/11/05/best-cheat-sheets-for-web-developers/
http://pushingbuttons.net/cheat/
http://www.addedbytes.com/cheat-sheets/
http://cakephp.org/files/cakesheet.pdf
http://www.serversidemagazine.com/cheat-sheets/PHP5/
http://techcheatsheets.com/

Javascript Linkize using jQuery

(Parse HTML page and automaticaly convert URLs in text to HTML links)

Here is a code to linkize text within an HTML node.

Pass a HTML element as parameter to the function.
It will parse the text, search for all urls and convert them to html links.

This is not the best method though. Still working on it.

/* Function to parse HTML text and convert URLs to HTML links. */
/* Author: Viraj Kanwade */
/* Parameter: the root element under which all HTML is to be linkized. */
/*
  The function parses child elements of root element.
    If the child node is an anchor, ignore it.
    If the child node is text element, getLinks function is called
      which parses HTML text and generated links.
    If the child node is any other node, the linkize function is called
      recurrsively.
*/
function linkize(root_elem) {
  var elems = jQuery(root_elem).contents().not(jQuery("a"));
  var len = elems.length;
  for(var i=0; i < len; i++) {
    var elem = elems[i];
    if(elem.nodeType == 3) {
    /* TODO: use regex
      var url_match = /https?:\/\/([-\w\.]+)+(:\d+)?(\/([\w/_\.]*(\?\S+)?)?)?/;
      var m = url_match.exec(elem.textContent);
      console.log(m);
    */
      jQuery(elem).replaceWith(genLinks(elem.textContent));
    } else if(elem.tagName != "A") {
      linkize(elem);
    }
  }
}

/* Function to parse HTML text and convert URLs in text to HTML links */
/* Author: Viraj Kanwade */
/* Parameter: HTML text to be parsed */
/* Returns: HTML text which has been linkized */
/*
  The function searches for URLs in the text provided. If no URL is found,
    it returns the original text. If a URL is found, it is linkized and the
    remaining string is passed recurrsively to the function.
*/
function genLinks(txt) {
  var http = "";
  var pos = -1;
  var pos1 = txt.indexOf("http://"); //get the first occurrence of HTTP:// in text
  var pos2 = txt.indexOf("https://"); //get the first occurrence of HTTPS:// in text
  var pos3 = txt.indexOf("www."); //get the first occurrence of WWW. in text
 
  // find which of the three occurs first
  if(pos1 > -1) {
    pos = pos1;
  }
  if(pos2 > -1) {
    if(pos == -1) {
      pos = pos2;
    } else if (pos2 < pos) {
      pos = pos2;
    }
  }
  if(pos3 > -1) {
    if(pos == -1) {
      pos = pos3;
    } else if (pos3 < pos) {
      pos = pos3;
    }
    http = "http://"; // since HTTP:// is missing from the URL (www.), it needs to be added in anchor.
  }
 
  if(pos != -1) { // URL found
    var txt2 = txt.substring(0, pos);
    pos1 = txt.indexOf(" ", pos); // Space is assumed to be the delimiter for URL
    if(pos1 == -1) {
      pos1 = txt.indexOf(String.fromCharCode(160), pos);
    }
    if(pos1 == -1) { // If space is not found, it can be assumed that it is the end of text.
      var txt3 = txt.substring(pos);
      txt2 += '<a href="' + http + txt3 + '" target="_blank">' + txt3 + '</a>';
    } else {
      /*
        Space is found. So it can be assumed that there is more text. Linkize the URL extracted and
        pass the remaining text for a recurrsive call to the function.
      */
      var txt3 = txt.substring(pos, pos1);
      txt2 += '<a href="' + http + txt3 + '" target="_blank">' + txt3 + '</a>';
      txt2 += genLinks(txt.substring(pos1));
    }
    return txt2; // Return linkized text.
  } else { // No URL found in text. Return original text.
    return txt;
  }
}
 

jQuery Linkize Plugin

Javascript XML Parsing

//Create a XMLDoc object from the xml string.

function getXMLDocObject(xmlstr) {
 var xmlDoc;
 try { //Internet Explorer
   try {
     xmlDoc=new ActiveXObject("MSXML2.DOMDocument"); 
   } catch(e) {
     xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
   }
   xmlDoc.async="false";
   xmlDoc.loadXML(xmlstr);
 } catch(e) {
   try { //Firefox, Mozilla, Opera, etc.
     parser=new DOMParser();
     xmlDoc=parser.parseFromString(xmlstr,"text/xml");
   } catch(e) {
     alert(e.message)
   }
 }
 return xmlDoc;
}

/* Consider the following XML

<?xml version="1.0" encoding="utf-8"?>
<rootnode>
 <error value='true'>
   <message>this is the message</message>
 </error>
</rootnode>

*/

// Create XMLDoc object
xmlDoc = getXMLDocObject(asyncreq.responseText);

// Get root node
var root = xmlDoc.getElementsByTagName('rootnode')[0];

/* You can loop over all child nodes of root using root.childNodes and root.childNodes.length */

// Will alert "error"
alert(root.childNodes[1].nodeName);

// Will alert "true";
alert(root.childNodes[1].getAttribute('value'));

// Will alert "message";
alert(root.childNodes[1].childNodes[1].nodeName);

// Will alert "this is the message".
alert(root.childNodes[1].childNodes[1].childNodes[0].nodeValue);