Question

I’m trying to construct an XML string to pass as the body of an HTTP request but I’m getting a bit stuck. Here’s the function that should build the string:

    public function build_calendarquery()
{

    $body = '<?xml version="1.0" encoding="utf-8" ?>
                    <C:'.$this->report_type.' xmlns:D="DAV:"
                    xmlns:C="urn:ietf:params:xml:ns:caldav">
                    <D:prop>
                        <D:getetag/>
                        <C:calendar-data>
                        <C:comp name="VCALENDAR">
                        <C:prop name="VERSION"/>
                        <C:comp name="VEVENT">'; 

        foreach($this->cal_props as $prop)
        {
            $body .= '<C:prop name="'.strtoupper($prop).'" />';                                                                
        }

        $body .= '</C:comp>';

        $body .= '<C:comp name="VTIMEZONE" />
                    </C:comp>
                        </C:calendar-data>
                        </D:prop>';

        if($this->filters){

            $body .= '<C:filter>
                        <C:comp-filter name="VCALENDAR">
                            <C:comp-filter name="VEVENT">';

            foreach($this->filters as $filter=>$val) 
            {
                $body .= '<C:'.$filter.' '.$val.'/>';
            }

            $body .= '</C:comp-filter>
                        </C:comp-filter>
                            </C:filter>';
        }

        $body .= '</C:calendar-query>'; 

        return $body;
}

The problem I have is that when I try and use the data returned from this function there doesn’t seem to be anything there. What I mean is, if I write:

var_dump($this->build_calendarquery()); 

It returns NULL.

I’ve never really worked with XML before. Am I missing something really obvious?

Answer 1

So I tested your code locally and there is nothing wrong with the part you have provided.

<?php
class Test
{
    public $report_type="foo";
    public $cal_props = array();
    public $filters = array();
    public function build_calendarquery()
    {

        $body = '<?xml version="1.0" encoding="utf-8" ?>
                        <C:'.$this->report_type.' xmlns:D="DAV:"
                        xmlns:C="urn:ietf:params:xml:ns:caldav">
                        <D:prop>
                            <D:getetag/>
                            <C:calendar-data>
                            <C:comp name="VCALENDAR">
                            <C:prop name="VERSION"/>
                            <C:comp name="VEVENT">'; 

            foreach($this->cal_props as $prop)
            {
                $body .= '<C:prop name="'.strtoupper($prop).'" />';                                                                
            }

            $body .= '</C:comp>';

            $body .= '<C:comp name="VTIMEZONE" />
                        </C:comp>
                            </C:calendar-data>
                            </D:prop>';

            if($this->filters){

                $body .= '<C:filter>
                            <C:comp-filter name="VCALENDAR">
                                <C:comp-filter name="VEVENT">';

                foreach($this->filters as $filter=>$val) 
                {
                    $body .= '<C:'.$filter.' '.$val.'/>';
                }

                $body .= '</C:comp-filter>
                            </C:comp-filter>
                                </C:filter>';
            }

            $body .= '</C:calendar-query>'; 

            return $body;
    }
    public function doVarDump()
    {
        var_dump($this->build_calendarquery());
    }
}

$test = new Test();
var_dump($test->build_calendarquery());
$test->doVarDump();
?>

outputs:

string '<?xml version="1.0" encoding="utf-8" ?>
                        <C:foo xmlns:D="DAV:"
                        xmlns:C="urn:ietf:params:xml:ns:caldav">
                        <D:prop>
                            <D:getetag/>
                            <C:calendar-data>
                            <C:comp name="VCALENDAR">
                            <C:prop name="VERSION"/>
                            <C:comp name="VEVENT"></C:comp><C:comp name="VTIMEZONE" />
                        </C:comp>
                            </C:calendar-data>
                            </D:prop></C:calendar-query>' (length=383)
string '<?xml version="1.0" encoding="utf-8" ?>
                        <C:foo xmlns:D="DAV:"
                        xmlns:C="urn:ietf:params:xml:ns:caldav">
                        <D:prop>
                            <D:getetag/>
                            <C:calendar-data>
                            <C:comp name="VCALENDAR">
                            <C:prop name="VERSION"/>
                            <C:comp name="VEVENT"></C:comp><C:comp name="VTIMEZONE" />
                        </C:comp>
                            </C:calendar-data>
                            </D:prop></C:calendar-query>' (length=383)

You will need to show us some more code. I’m interested as to where your var_dump($this->build_calendarquery()); statement is located.