How to upload files (multipart/form-data) with multidimensional POSTFIELDS using PHP and CURL?

Question

I\'m having problems with posting a multidimensional array with file uploads using PHP and CURL.

The multidimensional array is for example:

$post[\'q         


        

Answer 1

Another way to accomplish the first answer:

foreach( array("yes","no","maybe") as $key=>$value )
    $post["answers[$key]"] = $value;

Answer 2

multipart/form-data doesn't support nested values. And I don't believe CURL can do it either.

I suspect the receiving end of your request is also a PHP script. If, then you can submit a nested array as one of the values, if you just prepare it yourself:

 $post['answers[0]'] = "yes";
 $post['answers[1]'] = "no";
 $post['answers[2]'] = "maybe";

Theoretically you'd just need 'answers[]' without the index, but that would overwrite the preceeding value - and thus only works with http_build_query.

I'm not sure if there is any HTTP library in PHP which can do this automatically.

Answer 3

Try this recursive function.

https://gist.github.com/yisraeldov/ec29d520062575c204be7ab71d3ecd2f

<?php
function build_post_fields( $data,$existingKeys='',&$returnArray=[]){
    if(($data instanceof CURLFile) or !(is_array($data) or is_object($data))){
        $returnArray[$existingKeys]=$data;
        return $returnArray;
    }
    else{
        foreach ($data as $key => $item) {
            build_post_fields($item,$existingKeys?$existingKeys."[$key]":$key,$returnArray);
        }
        return $returnArray;
    }
}

And you can use it like this.

curl_setopt($ch, CURLOPT_POSTFIELDS, build_post_fields($postfields));