Aleenanne : Reference :Java Code

Reference JavaScript Code Library

HTTP 1.0 specifies a format for GET CGI action (<form method="GET" action="someURL">), which appends relevant data to the end of an executable URL in the format URL?key1=value1&key2=value2&.... This same CGI functionality can be mimicked by JavaScript on the client side where available, thereby saving server resources. This library module simplifies the JavaScript processing of client-side GET queries.

[Note: Netscape has posted a similar script for 4.0 browsers on its site. This script is based on Netscape's code in spirit, but extends its functionality by being compatible with almost every JavaScript browser.]

Method:

createRequestObject()
This is the method that parses the GET query. It reads the location of the resulting page, extracts the GET query from the end of the URL, and then parses the GET query into an associative array that can be used by other scripts on the page. It returns false if no data is received.

Usage:

Add the code to your page. The variable FORM_DATA is an associative array (hash) that contains your parsed GET information:

FORM_DATA [ key ] = value;

License: This code is released under the GNU Library General Public License.

Cut, paste, and enjoy!

/*
Webmonkey GET Parsing Module
Language: JavaScript 1.0

The parsing of GET queries is fundamental
to the basic functionality of HTTP/1.0.
This module parses GET with JavaScript 1.0.

Author: Patrick Corcoran
*/

function createRequestObject() {
  
  FORM_DATA = new Object();
    // The Object ("Array") where our data will be stored.
  
  separator = ',';
    // The token used to separate data from multi-select inputs
  
  query = '' + this.location;
    // Get the current URL so we can parse out the data.
    // Adding a null-string '' forces an implicit type cast
    // from property to string, for NS2 compatibility.
    
  query = query.substring((query.indexOf('?')) + 1);
    // Keep everything after the question mark '?'.
  
  if (query.length < 1) { return false; }  // Perhaps we got some bad data?
  
  keypairs = new Object();
  numKP = 1;
    // Local vars used to store and keep track of name/value pairs
    // as we parse them back into a usable form.
    
  while (query.indexOf('&') > -1) {
    keypairs[numKP] = query.substring(0,query.indexOf('&'));
    query = query.substring((query.indexOf('&')) + 1);
    numKP++;
      // Split the query string at each '&', storing the left-hand side
      // of the split in a new keypairs[] holder, and chopping the query
      // so that it gets the value of the right-hand string.
  }

keypairs[numKP] = query;
    // Store what's left in the query string as the final keypairs[] data.
  
  for (i in keypairs) {
    keyName = keypairs[i].substring(0,keypairs[i].indexOf('='));
      // Left of '=' is name.
    keyValue = keypairs[i].substring((keypairs[i].indexOf('=')) + 1);
      // Right of '=' is value.
    while (keyValue.indexOf('+') > -1) {
      keyValue = keyValue.substring(0,keyValue.indexOf('+')) + ' ' + keyValue.substring(keyValue.indexOf('+') + 1);
        // Replace each '+' in data string with a space.
    }
    
    keyValue = unescape(keyValue);
      // Unescape non-alphanumerics
      
    if (FORM_DATA[keyName]) {
      FORM_DATA[keyName] = FORM_DATA[keyName] + separator + keyValue;
        // Object already exists, it is probably a multi-select input,
        // and we need to generate a separator-delimited string
        // by appending to what we already have stored.
    } else {
      FORM_DATA[keyName] = keyValue;
        // Normal case: name gets value.
    }
  }

return FORM_DATA;
}

FORM_DATA = createRequestObject();
  // This is the array/object containing the GET data.
  // Retrieve information with 'FORM_DATA [ key ] = value'.

// -->

</script>