Importing Categories, Matrix fields and Super Table fields with Craft Import

BasePlugin.php

<?php
    /**
     * Modify data just before importing
     *
     * @param BaseElementModel $element  The current element receiving import data.
     * @param array            $map      Mapping of data between CSV -> Craft fields.
     * @param array            $data     Raw data provided for this row.
     */
    public function modifyImportRow($element, $map, $data)
    {
        // Map data to fields
        $fields = array_combine($map, $data);
        $categoryCriteria = craft()->elements->getCriteria(ElementType::Category);
        $categoryCriteria->limit(1);

        // Initialize content array
        $content = array();

        // Arrange your content in a way that makes sense for your plugin
        foreach ($fields as $handle => $value) {
            BelgraviaLogicPlugin::Log('Saving $content['.$handle.'] = '.$value, LogLevel::Info);
            $locationIdx = 1;

            // Handle neighborhood info
            switch ($handle) {
                case 'neighborhood':
                    // Need to lookup the ID of our category,
                    $categoryCriteria = craft()->elements->getCriteria(ElementType::Category);
                    $categoryCriteria->limit(1);
                    $categoryCriteria->group = 'neighborhood';
                    $categoryCriteria->title = $value;

                    $category = $categoryCriteria->first();

                    if (count($category) != 0) {
                        $content[$handle][] = $category->id;
                    }

                    continue;

                case 'state':
                    $content[$handle] = strtolower($value);

                    continue;

                case 'developmentType':
                    $categoryCriteria->group = 'developmentType';
                    $categoryCriteria->title = $value;

                    $type = $categoryCriteria->first();

                    if (count($type) != 0) {
                        $content[$handle][] = $type->id;
                    } else {
                        $content[$handle][] = 80; // Set to "Residential by default"
                    }

                    continue;

                case 'mainContent':
                    // Handle our body matrix field
                    $content[$handle]['new1']['type'] = 'richText';
                    $content[$handle]['new1']['enabled'] = '1';
                    $content[$handle]['new1']['fields']['body'] = $value;

                    continue;

                case 'location':
                    $content[$handle]['new'.$locationIdx]['type'] = '7';
                    $content[$handle]['new'.$locationIdx]['fields']['location'] = $value;

                    $locationIdx++;

                    continue;

                default:
                    $content[$handle] = $value;

                    continue;
            }
        }

        // Set modified content
        $element->setContentFromPost($content);
    }