Last active
August 29, 2015 14:01
-
-
Save dominic-p/6eb345194d508ecaf243 to your computer and use it in GitHub Desktop.
JavaScript Query String Parameter Update and Test Suite
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/** | |
* JavaScript Query string replacement function and test suite. | |
* | |
* The function is designed to add or update a query string parameter in a given | |
* URL. If all of the tests pass, the function should be pretty good. | |
*/ | |
var test_val = 'new', | |
test_uris = [ | |
[ 'http://example.com/', 'http://example.com/?param=' + test_val ], | |
[ 'http://example.com/?', 'http://example.com/?param=' + test_val ], | |
[ 'http://example.com/?param', 'http://example.com/?param=' + test_val ], | |
[ 'http://example.com/?param=val', 'http://example.com/?param=' + test_val ], | |
[ 'http://example.com/?param=val¶m2', 'http://example.com/?param=' + test_val + '¶m2' ], | |
[ 'http://example.com/?param=¶m2', 'http://example.com/?param=' + test_val + '¶m2' ], | |
[ 'http://example.com/?param=&param2', 'http://example.com/?param=' + test_val + '¶m2' ], | |
[ 'http://example.com/?param=val¶m2=val', 'http://example.com/?param=' + test_val + '¶m2=val' ], | |
[ 'http://example.com/?param2=val¶m[]=val', 'http://example.com/?param2=val¶m[]=' + test_val ], | |
[ 'http://example.com/?param[test]=val¶m2=val', 'http://example.com/?param[test]=' + test_val + '¶m2=val' ], | |
[ 'http://example.com/?param[test]=val¶m2[]=val', 'http://example.com/?param[test]=' + test_val + '¶m2[]=val' ], | |
[ 'http://example.com/?param[]=val¶m[]=another¶m2=val', 'http://example.com/?param[]=' + test_val + '¶m[]=' + test_val + '¶m2=val' ], | |
[ 'http://example.com/?param=val#', 'http://example.com/?param=' + test_val + '#' ], | |
[ 'http://example.com/?param=val¶m2=val#param=val', 'http://example.com/?param=' + test_val + '¶m2=val#param=val' ], | |
[ 'http://example.com/?param=val¶m2=val#param=val#test', 'http://example.com/?param=' + test_val + '¶m2=val#param=val#test' ], | |
[ 'http://example.com/?param2=val¶m=val#param=val#test?param=val', 'http://example.com/?param2=val¶m=' + test_val + '#param=val#test?param=val' ], | |
[ 'http://example.com/#param=val', 'http://example.com/?param=' + test_val + '#param=val' ], | |
[ 'http://example.com/#test-string', 'http://example.com/?param=' + test_val + '#test-string' ], | |
[ 'http://example.com/#?test-string', 'http://example.com/?param=' + test_val + '#?test-string' ] | |
], | |
len = test_uris.length, | |
output, | |
result; | |
// Loop through all of the test URIs and check them against the function | |
for ( var i = 0; i < len; i++ ) { | |
output = update_query_string( test_uris[i][0], 'param', test_val ); | |
result = ( ( output === test_uris[i][1] ) ? 'PASS' : 'FAIL' ); | |
// Output, result :: old_uri :: new_uri | |
console.log( result + ' :: ' + test_uris[i][0] + ' :: ' + output ); | |
// If a test failed, indicate what the expected value was | |
if ( 'FAIL' == result ) { | |
console.log( ' Expected: ' + test_uris[i][1] ); | |
} | |
} | |
/** | |
* Add or update a query string parameter. If no URI is given, we use the current | |
* window.location.href value for the URI. | |
* | |
* Based on the DOM URL parser described here: | |
* http://james.padolsey.com/javascript/parsing-urls-with-the-dom/ | |
* | |
* @param (string) uri Optional: The URI to add or update a parameter in | |
* @param (string) key The key to add or update | |
* @param (string) value The new value to set for key | |
* | |
* Tested on Chrome 34, Firefox 29, IE 7 and 11 | |
*/ | |
function update_query_string( uri, key, value ) { | |
// Use window URL if no query string is provided | |
if ( ! uri ) { uri = window.location.href; } | |
// Create a dummy element to parse the URI with | |
var a = document.createElement( 'a' ), | |
// match the key, optional square bracktes, an equals sign or end of string, the optional value | |
reg_ex = new RegExp( key + '((?:\\[[^\\]]*\\])?)(=|$)(.*)' ), | |
// Setup some additional variables | |
qs, | |
qs_len, | |
key_found = false; | |
// Use the JS API to parse the URI | |
a.href = uri; | |
// If the URI doesn't have a query string, add it and return | |
if ( ! a.search ) { | |
a.search = '?' + key + '=' + value; | |
return a.href; | |
} | |
// Split the query string by ampersands | |
qs = a.search.replace( /^\?/, '' ).split( /&(?:amp;)?/ ); | |
qs_len = qs.length; | |
// Loop through each query string part | |
while ( qs_len > 0 ) { | |
qs_len--; | |
// Check if the current part matches our key | |
if ( reg_ex.test( qs[qs_len] ) ) { | |
// Replace the current value | |
qs[qs_len] = qs[qs_len].replace( reg_ex, key + '$1' ) + '=' + value; | |
key_found = true; | |
} | |
} | |
// If we haven't replaced any occurences above, add the new parameter and value | |
if ( ! key_found ) { qs.push( key + '=' + value ); } | |
// Set the new query string | |
a.search = '?' + qs.join( '&' ); | |
return a.href; | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment