Creating simple xml file using Drupal

Here is the snippet to create an xml file using our custom module. We can customise tags, attributes and values for the xml elements.

    $dom = new DomDocument('1.0');

    //add root - <parent>
    $parent = $dom->appendChild($dom->createElement('parent'));

    //set attributes to <parent> tag
    $parent->setAttribute("name", "parent1");

    //add <child1> element to <parent>
    $child1 = $parent->appendChild($dom->createElement('child1'));

    //add elements to <child1>
    $schema = $child1->appendChild($dom->createElement('schema'));
    $schema->appendChild($dom->createTextNode('Schema Name')); //add <title> text node element to <schema>
    $schemaversion = $child1->appendChild($dom->createElement('schemaversion'));
    $schemaversion->appendChild($dom->createTextNode('1.1.0'));

    //add <child2> element to <parent>              
    $child2 = $parent->appendChild($dom->createElement('child2'));
    //add elements to <child2>
    $listr = array('value1','value2');

    $i = 1;
    foreach ($listr as $parent => $href) {
                $baby = $child2->appendChild($dom->createElement('baby'));
                $baby->setAttribute("href", $href);
                $baby->setAttribute("type", "webcontent");
                $baby->setAttribute("intendeduse", "unspecified");
                $babyfile = $baby->appendChild($dom->createElement('file'));
                $babyfile->setAttribute("href", $href);
                $i++;
    }

    // generate xml
    $dom->formatOutput = true; // set the formatOutput attribute of dom Document to true
    $test1 = $dom->saveXML(); // save XML as string or file
    $dom->save('simple.xml'); // save as file 

Simple Drupal CRON

Here is the snippet for simple cron using custom module. We are just calling a function while executing the cron (menucallback).

/**
 * Implements hook_cronapi().
 */
function modulename_cronapi($op, $function=NULL) {
    switch ($op) {
        case 'list':
            return array('modulename_cronname' => t('CRON Human Readable Name'));
        case 'rule':
            return '*/20 * * * *';
        case 'execute':
            return 'menucallback';
    }
}

After this refresh the module cache and go to admin/config/system/cron to view this newly created cron.

Wget to download your site HTML pages

Here is the snipped to download your site as html with some restriction,

- This will not download jpeg,jpg,png,gif,mpeg,mp4 files.
- This will not download files under 'anyfolder' (sites/anyfolder)
- This will download your files inside 'files' (sites/files)

wget -p -nH --restrict-file-names=nocontrol -R jpeg,jpg,png,gif,mpeg,mp4 -X sites/anyfolder --html-extension -e robots=off --base=./ -k -P sites/files

Delete a directory recursively

Here is the snippet to delete the folder and its children folder, files recursively.

function delete_directory($dir) {
    if ($handle = opendir($dir)) {
        while (false !== ($file = readdir($handle))) {
            if ($file != "." && $file != "..") {
                if(is_dir($dir.$file)) {
                    if(!@rmdir($dir.$file)) { // Empty directory? Remove it
                        delete_directory($dir.$file.'/'); // Not empty? Delete the files inside it
                    }
                }
                else {
                   @unlink($dir.$file);
                }
            }
        }
        closedir($handle);
        @rmdir($dir);
    }
}

db_merge combination of db_insert and db_update

In drupal 7, there is a something new for table insertion and update. That is called db_merge which combines db_insert and db_update in a single query for single or multiple row insert and update.

$query = db_merge('table_name')
                ->insertFields(array(
                    'field1' => value1,
                    'field2' => value2,
                    'field3' => value3,
                ))
                ->updateFields(array(
                    'field3' => value3,
                ))
                ->key(array('field2' => value2))
                ->execute();