Differentiate between a parameter that can take either file contents or file path in PHP

Question

Hey all,

I'm implementing a function called attach. I'm looking for a way to take a param that is either a file path or a file's contents. Here's what I have:

/**
 *  @param name - name of the file
 *  @param file - either a file or a file path
 */
function attach($name, $file) {
    $attachment = array();

    $attachment['name'] = $name;

    if(map($file)) {
        $attachment['filepath'] = $file;
        $attachment['file'] = file_get_contents($file);
    } else {
        $attachment['file'] = $file;
        $attachment['filepath'] = getcwd();
    }
}

/**
 * @param filepath - can take multiple forms
 *   ie. ui:form:text.css => ui/form/text.css
 *       text.css => getcwd().'text.css'
 *       /ui/form/text.css => /ui/form/text.css
 * 
 * @return if file exists - return file path
 *         if not found - return false
*/

function map($filepath) {
   // ... too long to post
}

The map function allows you to turn namespaces (using ":") into filepaths.

The issue I'm worried about is if an error is made in the filepath (ie. someone types in the file path wrong) I don't want it to think that since the file doesn't exist, it must be file contents

Also: if possible, i'd rather not edit map() as it would require me to change a bunch of code - consider map as a black box.

Finally: I put this example together quickly - so please do not discuss the shortcomings of getcwd(), and other syntactical issues. I have a more elaborate system in place in map()

Thanks! Matt Mueller

Answer 1

Before adding the attachment your code could use a function like file_exists to determine if what seems like a path actually is a path and the file does in fact exist. Additionally you may want to check if the path refers to a folder or a file.

Answer 2

Even if PHP had better support for method overloading, you'd have a hard time here since both vars (filepath and file contents) would probably be a string. What is preventing you from just creating a couple of wrapper methods, like attach_filepath(..), attach_filecontents(..)? Or, if you are set on having one method, you could add a third param, like:

function attach($name, $file, $filecontents=false) {

I agree that it would probably be a bad idea to try to guess the users' intentions based on the contents of a var that would have the same type in both cases.