#32524 [Com]: Advanced imploding

ID: 32524 Comment by: c dot duvergier dot div at online dot fr Reported By: bart at mediawave dot nl Status: Open Bug Type: Feature/Change Request Operating System: Any PHP Version: 5CVS-2005-04-01 (dev) New Comment: My suggestion to solve that problem is the following (I was going to open a new bug, but since you already did it, let's continue here) : I would suggest to modify implode() so that a callback function can be specified. Example: -------- $pieces = array('A', 'suggestion'); echo implode_callback(' | ', $pieces, 'crc32'); Description of need: -------------------- Actually, implode(string $glue, array $pieces) uses __toString() function on each element of $pieces before glueing them together. It would be usefull to have the possibility to call a user-defined function instead (such as data verification, string transformation). Could be done by doing an array_walk() on $pieces and then an implode on the modified array, but that implies to traverse the array twice. In #40097, Derick suggested a bogus solution : array_walk(implode('-', $string), 'callbackFunc'); (doesn't work as first array_walk() parameter must be an array. Still it doesn't fix performance issue. Previous Comments: ------------------------------------------------------------------------ [2005-04-01 01:11:23] bart at mediawave dot nl Description: ------------ I often find myself being in the situation where I need more advanced ways to implode() something. For example, a way to implode an array into: "table1 AS alias1, table2 AS alias2, table3 AS alias3" or: "var1=value1&var2=value2&var3=value3" I would like to make 3 suggestions to implement such a functionality in PHP. 1) Extend implode so that it can handle a second (or more?) "glue" argument. $vars = array( 'var1' => 'value1', 'var2' => 'value2', 'var3' => 'value3' ); or maybe it would need a multidimensional array: $vars = array( array('var1', 'value1'), array('var2', 'value2'), array('var3', 'value3') ); echo implode($vars, '=', '&'); // Would print: var1=value1&var2=value2&var3=value3 The problem here is that implode would need to get its arguments in a different order. Perhaps, this could be solved by creating a new function. 2) Modify array_map() so that, when the third argument is a string, it is always passed along as an extra argument to all the function calls: $vars = array( array('var1', 'value1'), array('var2', 'value2'), array('var3', 'value3') ); echo implode('&', array_map('implode', $vars, '=')); // Would print: var1=value1&var2=value2&var3=value3 3) This is probably the most powerfull and elegant solution. (My personal favourite) Modify the __toString() magic method so that, when an object is passed to a function that needs a string as input, __toString() is called. In this example __toString() could be something like: function __toString() { return $this->name.'='.$this->value; } And the implode() code could look like: $vars = array( new urlVar('var1', 'value1'), new urlVar('var1', 'value1'), new urlVar('var1', 'value1') ); echo implode($vars, '&'); // Would print: var1=value1&var2=value2&var3=value3 This could also produce more complex strings like: "WHERE var1='value1' AND var2='value2' OR var3='value3'" ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=32524&edit=1