Creating and updating model and its related models in one form, inc. image Follow @yiiframework

class Artist extends PcBaseArModel {
    // more code...
    /**
     * @return array relational rules.
     */
    public function relations() {
        return array(
            'songs' => array(self::HAS_MANY, 'Song', 'artist_id'),
        );
    }
    // more code...
}

class Song extends PcBaseArModel {
    // more code...
    /**
     * @return array relational rules.
     */
    public function relations() {
        return array(
            'artist' => array(self::BELONGS_TO, 'Artist', 'artist_id'),
        );
    }
    // more code...
}

class ArtistController extends Controller {
    public function actionCreate() {
        /*
         * first, do some permission's check. I use Yii's RBAC facility. YMMV, and it doesn't matter. Just do a
         * permissions check here.
         */
        if (!Yii::app()->user->checkAccess('create artist')) {
            // not allowed... .
            throw new CHttpException(401);
        }
 
        $model = new Artist('insert');
        $song = new Song('insert');
        // by default, if we already submitted the form and if we didn't, we allow adding more songs
        // this will be updated down below if needed to
        $enable_add_more_songs = true;
 
        if (isset($_POST['Artist'])) {
            // start optimistically by settings a few variables that we'll need
            $all_songs_valid = true;
            $songs_to_save = array();
            $success_saving_all = true;
 
            $model->attributes = $_POST['Artist'];
 
            // use aux variable for manipulating the image file. 'icon_filename' is the attribute name in the Artist model
            $image = CUploadedFile::getInstance($model, 'icon_filename');
            // we need to put something into the icon_filename of the model since otherwise validation will fail if its
            // a 'required' field (this is 'create' scenario).
            if ($image) {
                // if its not required field and image wasn't supplied this block will not be run so
                // this is safe for both 'required field' and 'non required field' use cases.
                $model->icon_filename = "(TEMP) " . $image->name;
            }
 
            // lets start handle related models that were submitted, if any
            if (isset($_POST['Song'])) {
                if (count($_POST['Song']) > Song::MAX_SONGS_PER_ARTIST) {
                    /*
                     * server side protection against attempt to submit more than MAX_SONGS_PER_ARTIST
                     * this should be accompanied with a client side (JS) protection.
                     * If its accompanied with client side protection then going into this code block means our system
                     * is being abused/"tested". No need to give a polite error message.
                     */
                    throw new CHttpException(500, Yii::t("MusicModule.forms", "The max amount of allowed songs is {max_songs_num}", array('{max_songs_num}' => Song::MAX_SONGS_PER_ARTIST)));
                }
                // now handle each submitted song:
                foreach ($_POST['Song'] as $index => $submitted_song) {
                    // We could have empty songs which means empty submitted forms in POST. Ignore those:
                    if ($submitted_song['title'] == '') {
                        // empty one - skip it, if you please.
                        continue;
                    }
 
                    // validate each submitted song instance
                    $song = new Song();
                    $song->attributes = $submitted_song;
                    if (!$song->validate()) {
                        // at least one invalid song. We'll need to remember this fact in order to render the create
                        // form back to the user, with the error message:
                        $all_songs_valid = false;
                        // we do not 'break' here since we want validation on all songs at the same shot
                    }
                    else {
                        // put aside the new *and valid* Song to be saved
                        $songs_to_save[] = $song;
                    }
                }
 
                // while we know that songs were submitted, determine if the number of songs has exceeded its limit.
                // this will be goof when rendering back the 'create' form so no more songs-forms will be available.
                if (count($_POST['Song']) == Song::MAX_SONGS_PER_ARTIST) {
                    $enable_add_more_songs = false;
                }
            }
 
            // Done validation. Summarize all valid/invalid information thus far and act accordingly
            if ($all_songs_valid && $model->validate()) {
                /*
                 * all songs (if any) were valid and artist model is valid too. Save it all in one transaction. Save first the
                 * artist as we need its 'id' attribute for its songs records (Song.artist_id is NOT NULL in the DB level
                 * and a 'required' attribute in our model).
                 */
                $trans = Yii::app()->db->beginTransaction();
 
                try {
                    // save the artist
                    $model->save(false);
                    // handle image of artist, if supplied:
                    if ($image) {
                        // Song.getImageFsFilename() encapsulates the image filename setting details.
                        $image->saveAs($model->getImageFsFilename($image));
                        /**
                         * now update the model itself again with the full filename of the image file.
                         * this is the disadvantage of using filenames that include the PK of the entry - we need it first saved
                         * in the DB before we know what it is... . */
                        // icon_filename is a VARCHAR(512) in the DB (for long filenames) and 'string' in the Artist model
                        $model->icon_filename = $model->getImageFsFilename($image);
                        $model->save(false);
                    }
 
                    // save the songs
                    foreach ($songs_to_save as $song) {
                        $song->artist_id = $model->id;
                        $song->save(false);
                    }
 
                    // here, it means no exception was thrown during saving of artist and its songs (from the DB, for example).
                    // good - now commit it all...:
                    $trans->commit();
                }
                catch (Exception $e) {
                    // oops, saving artist or its songs failed. rollback, report us, and show the user an error.
                    $trans->rollback();
                    Yii::log("Error occurred while saving artist or its 'songs'. Rolling back... . Failure reason as reported in exception: " . $e->getMessage(), CLogger::LEVEL_ERROR, __METHOD__);
                    Yii::app()->user->setFlash('error', Yii::t("MusicModule.forms", "Error occurred"));
                    $success_saving_all = false;
                }
 
                if ($success_saving_all) {
                    // everything's done. Would you believe it?! Go to 'view' page :)
                    $success_msg = (count($songs_to_save) > 0) ? "Artist and song records has been created successfully!" : "Artist record has been created successfully!";
                    Yii::app()->user->setFlash('success', Yii::t("MusicModule.forms", $success_msg));
                    $this->redirect(array("view", "id" => $model->id));
                }
            }
        }
 
        $this->render('create', array(
            'artist' => $model,
            'songs' => (isset($songs_to_save)) ? $songs_to_save : array(new Song('insert')),
            'enable_add_more_songs' => $enable_add_more_songs,
        ));
    }
}

class ArtistController extends Controller {
    public function actionUpdate($id) {
        /* @var Artist $model */
        $model = $this->loadModel($id);
 
        // check access
        if (!Yii::app()->user->checkAccess('edit artist')) {
            throw new CHttpException(401);
        }
 
        // does this artists exists in our DB?
        if ($model === null) {
            Yii::log("Artist update requested with id $id but no such artist found!", CLogger::LEVEL_INFO, __METHOD__);
            throw new CHttpException(404, Yii::t("MusicModule.general", 'The requested page does not exist.'));
        }
 
        // enable adding songs by default (will be changed below if needed to)
        $enable_add_more_songs = true;
 
        if (isset($_POST['Artist'])) {
            // start optimistically
            $all_songs_valid = true;
            $songs_to_save = array();
            $success_saving_all = true;
 
            $model->attributes = $_POST['Artist'];
            if (isset($_POST['Song'])) {
                if (count($_POST['Song']) > Song::MAX_SONGS_PER_ARTIST) {
                    /*
                     * server side protection against attempt to submit more than MAX_SONGS_PER_ARTIST
                     * this should be accompanied with a client side (JS) protection.
                     * If its accompanied with client side protection then going into this code block means our system
                     * is being abused/"tested". No need to give a polite error message.
                     */
                    throw new CHttpException(500, Yii::t("MusicModule.forms", "The max amount of allowed songs is {max_songs_num}", array('{max_songs_num}' => Song::MAX_SONGS_PER_ARTIST)));
                }
                foreach ($_POST['Song'] as $index => $submitted_song) {
                    // We could have empty songs which means empty submitted forms in POST. Ignore those:
                    if ($submitted_song['title'] == '') {
                        // empty one - skip it, if you please.
                        continue;
                    }
 
                    // next, validate each submitted song instance
                    if ((int)$submitted_song['id'] > 0) {
                        /* Validate that the submitted song belong to this artist */
                        $song = Song::model()->findByPk($submitted_song['id']);
                        if ($song->artist->id != $model->id) {
                            Yii::log("Attempts to update Song with an id of {$song->id} but it belongs to an Artist with an id of {$song->model->id}" .
                                    " and not 'this' artist with id = {$model->id}", CLogger::LEVEL_ERROR, __METHOD__);
                            throw new CHttpException(500, "Error occurred");
                        }
                    }
                    else {
                        // this submitted song object is a new model. instantiate one:
                        $song = new Song();
                    }
 
                    $song->attributes = $submitted_song;
                    if (!$song->validate()) {
                        // at least one invalid song:
                        $all_songs_valid = false;
                        // we do not 'break' here since we want validation on all song at the same shot
                    }
                    else {
                        // put aside the valid song to be saved
                        $songs_to_save[] = $song;
                    }
                }
 
                // while we know that songs were submitted, determine if to show 'adding songs' or no.
                // a check whether the max songs per artist was exceeded was performed already above.
                if (count($_POST['Song']) == Song::MAX_SONGS_PER_ARTIST) {
                    $enable_add_more_songs = false;
                }
            }
 
            if ($all_songs_valid && $model->validate()) {
                /* all songs (if any) were valid and artist object is valid too. Save it all in one transaction. Save first the
                 * artist as we need its id for its songs records
                 */
                $trans = Yii::app()->db->beginTransaction();
 
                try {
                    // use aux variable for manipulating the image file.
                    $image = CUploadedFile::getInstance($model, 'icon_filename');
                    // check if a new image was submitted or not:
                    if ($image) {
                        /* the only thing that might have changed in the update is the extension name of the image (if you support more than 'only jpeg').
                         * therefore, if something was submitted, and since we already know the ID of the artist (this is an update scenario), we can
                         * determine the full updated icon_filename attribute of the model prior to its save() (unlike in create action - see there...).
                         */
                        $model->icon_filename = $model->getImageFsFilename($image);
                    }
 
                    $model->save(false);
                    // save the updated image, if any
                    if ($image) {
                        $image->saveAs($model->getImageFsFilename($image));
                    }
 
                    // save songs
                    foreach ($songs_to_save as $song) {
                        $song->save(false);
                    }
                    $trans->commit();
                }
                catch (Exception $e) {
                    // oops, saving artist or its songs failed. rollback, report us, and show the user an error.
                    $trans->rollback();
                    Yii::log("Error occurred while saving (update scenario) artist or its 'songs'. Rolling back... . Failure reason as reported in exception: " . $e->getMessage(), CLogger::LEVEL_ERROR, __METHOD__);
                    Yii::app()->user->setFlash('error', Yii::t("MusicModule.forms", "Error occurred"));
                    $success_saving_all = false;
                }
 
                if ($success_saving_all) {
                    $success_msg = (count($songs_to_save) > 0) ? "Artist and song records have been updated" : "Artist record have been updated";
                    Yii::app()->user->setFlash('success', Yii::t("MusicModule.forms", $success_msg));
                    $this->redirect(array("view", "id" => $model->id));
                }
            }
        }
        else {
            // initial rendering of update form. prepare songs for printing.
            // we put it in the same variable as used for saving (that's the reason for the awkward variable naming).
            $songs_to_save = $model->songs;
        }
 
        $this->render('update', array(
            'artist' => $model,
            'songs' => (isset($songs_to_save)) ? $songs_to_save : array(new Song('insert')),
            'enable_add_more_songs' => $enable_add_more_songs,
        ));
    }
}

<?php
/* @var $this ArtistController */
/* @var $artist Artist */
/* @var $songs array */
/* @var $form CActiveForm */
/* @var $enable_add_more_songs bool */
?>
 
<div class="form">
    <?php $form = $this->beginWidget('CActiveForm', array(
    'id' => 'artist-form',
    'enableAjaxValidation' => false,
    // we need the next one for transmission of files in the form.
    'htmlOptions' => array('enctype' => 'multipart/form-data'),
)); ?>
 
    <p class="note">Fields with <span class="required">*</span> are required.</p>
 
    <?php echo $form->errorSummary($artist); ?>
 
    <?php // All 'regular' artist form fields were omitted...  ?>
 
    <fieldset>
        <legend><?php echo Yii::t("MusicModule.forms", "Songs"); ?></legend>
        <div id="songs-multiple">
            <?php
            $i = 0;
            foreach ($songs as $song) {
                /* @var Song $song */
                $this->renderPartial('/songs/_form', array('model' => $song, 'counter' => $i));
                $i++;
            }
            ?>
            <?php
            // add button to 'add' a song if adding more songs is enabled
            if ($enable_add_more_songs) {
                // print the button here, which replicates the form but advances its counters
                // add the blank, extra 'song' form, with display=none... :
                echo '<div id="extra-song" style="display: none;">';
                $this->renderPartial('/song/_form', array('model' => new Song(), 'counter' => $i));
                echo "</div>";
            }
            ?>
        </div>
    </fieldset>
 
    <div class="row">
        <?php echo $form->labelEx($artist, 'icon_filename'); ?>
        <?php if (isset($update) && ($update === true)) { ?>
        <div><?php echo 'Choose new file or leave empty to keep current image.';?></div>
        <?php } ?>
        <?php echo $form->fileField($artist, 'icon_filename', array('size' => 20, 'maxlength' => 512)); ?>
        <?php echo $form->error($artist, 'icon_filename'); ?>
    </div>
 
    <div class="row buttons">
        <?php echo CHtml::submitButton($artist->isNewRecord ? 'Create' : 'Save'); ?>
    </div>
 
    <?php $this->endWidget(); ?>
</div>

<?php
/* @var Song $song */
/* @var int $counter */
 
/*
 * Design note: in order to prevent nested forms that will possibly confuse yii we render this form using simple CHtml methods
 *  (like beginForm()) and not using CActiveForm
 */
?>
<div class="form">
    <?php
    echo CHtml::beginForm();
    ?>
    <div class="song-<?php echo $counter ?>">
        <div class="row">
            <?php
            // if this is an 'update' use case (form re-use), render also the id of the song itself (so upon submission we'll
            // know which song to update. Check if $song->id exists...
            ?>
        </div>
 
        <?php
        /*
         * Rest of the form fields should be rendered here, using CHtml::...
         */
        ?>
    </div>
 
    <?php CHtml::endForm(); ?>
</div>