Ui Template / Adminhtml issue

Question

I'm working through some ui component issues with an adminhtml ui component/grid I've been trying to get working. Let me toss out the error and then some code. Let me know if I need to post more code/info.

Error:

Fatal error: Method Magento\Ui\TemplateEngine\Xhtml\Result::__toString() must not throw an exception, caught TypeError: Argument 1 passed to Magento\Framework\View\Element\UiComponent\DataProvider\DataProvider::searchResultToOutput() must implement interface Magento\Framework\Api\Search\SearchResultInterface, instance of Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Collection\Interceptor given, called in /var/www/danwcpdev/html/vendor/magento/framework/View/Element/UiComponent/DataProvider/DataProvider.php on line 284 in /var/www/danwcpdev/html/vendor/magento/module-ui/Component/Wrapper/UiComponent.php on line 0

<?xml version="1.0" encoding="UTF-8"?>
<listing xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Ui/etc/ui_configuration.xsd">
    <argument name="data" xsi:type="array">
        <item name="js_config" xsi:type="array">
            <item name="provider" xsi:type="string">offers_ui.offers_ui_listing_data_source</item>
            <item name="deps" xsi:type="string">offers_ui.offers_ui_listing_data_source</item>
        </item>
        <item name="spinner" xsi:type="string">offers_ui_data_columns</item>
        <item name="buttons" xsi:type="array">
            <item name="add" xsi:type="array">
                <item name="name" xsi:type="string">add</item>
                <item name="label" xsi:type="string" translate="true">Add New Offer</item>
                <item name="class" xsi:type="string">primary</item>
                <item name="url" xsi:type="string">*/*/new</item>
            </item>
        </item>
    </argument>
    <dataSource name="offers_ui_listing_data_source">
        <argument name="dataProvider" xsi:type="configurableObject">
            <argument name="class" xsi:type="string">Magento\Framework\View\Element\UiComponent\DataProvider\DataProvider</argument>
            <argument name="name" xsi:type="string">offers_ui_listing_data_source</argument>
            <argument name="primaryFieldName" xsi:type="string">offers_id</argument>
            <argument name="requestFieldName" xsi:type="string">offers_id</argument>
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="update_url" xsi:type="url" path="mui/index/render"/>
                </item>
            </argument>
        </argument>
        <argument name="data" xsi:type="array">
            <item name="js_config" xsi:type="array">
                <item name="component" xsi:type="string">Magento_Ui/js/grid/provider</item>
            </item>
        </argument>
    </dataSource>
    <container name="listing_top">
        <argument name="data" xsi:type="array">
            <item name="config" xsi:type="array">
                <item name="template" xsi:type="string">ui/grid/toolbar</item>
            </item>
        </argument>
        <bookmark name="bookmarks">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="storageConfig" xsi:type="array">
                        <item name="namespace" xsi:type="string">offers_ui</item>
                    </item>
                </item>
            </argument>
        </bookmark>
        <container name="columns_controls">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="columnsData" xsi:type="array">
                        <item name="provider" xsi:type="string">offers_ui.offers_ui.offers_ui_data_columns</item>
                    </item>
                    <item name="component" xsi:type="string">Magento_Ui/js/grid/controls/columns</item>
                    <item name="displayArea" xsi:type="string">dataGridActions</item>
                </item>
            </argument>
        </container>
        <filters name="listing_filters">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="displayArea" xsi:type="string">dataGridFilters</item>
                    <item name="dataScope" xsi:type="string">filters</item>
                    <item name="storageConfig" xsi:type="array">
                        <item name="provider" xsi:type="string">offers_ui.offers_ui.listing_top.bookmarks</item>
                        <item name="namespace" xsi:type="string">current.filters</item>
                    </item>
                    <item name="childDefaults" xsi:type="array">
                        <item name="provider" xsi:type="string">offers_ui.offers_ui.listing_top.listing_filters</item>
                        <item name="imports" xsi:type="array">
                            <item name="visible" xsi:type="string">offers_ui.offers_ui.listing_top.bookmarks:current.columns.${ $.index }.visible</item>
                        </item>
                    </item>
                </item>
            </argument>
            <filterRange name="offers_id">
                <argument name="data" xsi:type="array">
                    <item name="config" xsi:type="array">
                        <item name="dataScope" xsi:type="string">offers_id</item>
                        <item name="label" xsi:type="string" translate="true">ID</item>
                        <item name="childDefaults" xsi:type="array">
                            <item name="provider" xsi:type="string">offers_ui.offers_ui.listing_top.listing_filters</item>
                        </item>
                    </item>
                </argument>
                <filterInput name="from">
                    <argument name="data" xsi:type="array">
                        <item name="config" xsi:type="array">
                            <item name="dataScope" xsi:type="string">from</item>
                            <item name="label" xsi:type="string" translate="true">from</item>
                            <item name="placeholder" xsi:type="string" translate="true">From</item>
                        </item>
                    </argument>
                </filterInput>
                <filterInput name="to">
                    <argument name="data" xsi:type="array">
                        <item name="config" xsi:type="array">
                            <item name="dataScope" xsi:type="string">to</item>
                            <item name="label" xsi:type="string" translate="true">to</item>
                            <item name="placeholder" xsi:type="string" translate="true">To</item>
                        </item>
                    </argument>
                </filterInput>
            </filterRange>
            <filterInput name="last_name">
                <argument name="data" xsi:type="array">
                    <item name="config" xsi:type="array">
                        <item name="dataScope" xsi:type="string">last_name</item>
                        <item name="label" xsi:type="string" translate="true">Last Name</item>
                    </item>
                </argument>
            </filterInput>
            <filterInput name="status">
                <argument name="data" xsi:type="array">
                    <item name="config" xsi:type="array">
                        <item name="dataScope" xsi:type="string">status</item>
                        <item name="label" xsi:type="string" translate="true">Status</item>
                    </item>
                </argument>
            </filterInput>
        </filters>
        <paging name="listing_paging">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="storageConfig" xsi:type="array">
                        <item name="provider" xsi:type="string">offers_ui.offers_ui.listing_top.bookmarks</item>
                        <item name="namespace" xsi:type="string">current.paging</item>
                    </item>
                    <item name="selectProvider" xsi:type="string">offers_ui.offers_ui.offers_ui_data_columns.ids</item>
                    <item name="displayArea" xsi:type="string">bottom</item>
                </item>
            </argument>
        </paging>
    </container>
    <columns name="offers_ui_data_columns">
        <argument name="data" xsi:type="array">
            <item name="config" xsi:type="array">
                <item name="storageConfig" xsi:type="array">
                    <item name="provider" xsi:type="string">offers_ui.offers_ui.listing_top.bookmarks</item>
                    <item name="namespace" xsi:type="string">current</item>
                </item>
                <item name="childDefaults" xsi:type="array">
                    <item name="fieldAction" xsi:type="array">
                        <item name="provider" xsi:type="string">offers_ui.offers_ui.offers_ui_data_columns.actions</item>
                        <item name="target" xsi:type="string">applyAction</item>
                        <item name="params" xsi:type="array">
                            <item name="0" xsi:type="string">edit</item>
                            <item name="1" xsi:type="string">${ $.$data.rowIndex }</item>
                        </item>
                    </item>
                    <item name="storageConfig" xsi:type="array">
                        <item name="provider" xsi:type="string">offers_ui.offers_ui.listing_top.bookmarks</item>
                        <item name="root" xsi:type="string">columns.${ $.index }</item>
                        <item name="namespace" xsi:type="string">current.${ $.storageConfig.root}</item>
                    </item>
                </item>
            </item>
        </argument>
        <selectionsColumn name="ids">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="indexField" xsi:type="string">offers_id</item>
                    <item name="sortOrder" xsi:type="number">0</item>
                </item>
            </argument>
        </selectionsColumn>
        <column name="offers_id">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="filter" xsi:type="string">text</item>
                    <item name="component" xsi:type="string">Magento_Ui/js/grid/columns/column</item>
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">ID</item>
                    <item name="sortOrder" xsi:type="number">10</item>
                </item>
            </argument>
        </column>
        <column name="first_name">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="filter" xsi:type="string">text</item>
                    <item name="component" xsi:type="string">Magento_Ui/js/grid/columns/column</item>
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">first_name</item>
                    <item name="sortOrder" xsi:type="number">20</item>
                </item>
            </argument>
        </column>
        <column name="last_name">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="filter" xsi:type="string">text</item>
                    <item name="component" xsi:type="string">Magento_Ui/js/grid/columns/column</item>
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">last_name</item>
                    <item name="sortOrder" xsi:type="number">25</item>
                </item>
            </argument>
        </column>
         <column name="customer_email">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="filter" xsi:type="string">text</item>
                    <item name="component" xsi:type="string">Magento_Ui/js/grid/columns/column</item>
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">customer_email</item>
                    <item name="sortOrder" xsi:type="number">20</item>
                </item>
            </argument>
        </column>
         <column name="message">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="filter" xsi:type="string">text</item>
                    <item name="component" xsi:type="string">Magento_Ui/js/grid/columns/column</item>
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">message</item>
                    <item name="sortOrder" xsi:type="number">30</item>
                </item>
            </argument>
        </column>
         <column name="offer_amount">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="filter" xsi:type="string">text</item>
                    <item name="component" xsi:type="string">Magento_Ui/js/grid/columns/column</item>
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">Offer</item>
                    <item name="sortOrder" xsi:type="number">90</item>
                </item>
            </argument>
        </column>
        <column name="status">
            <argument name="data" xsi:type="array">
                <item name="options" xsi:type="object">Wundercarparts\Makeanoffer\Model\Status</item>
                <item name="config" xsi:type="array">
                    <item name="filter" xsi:type="string">select</item>
                    <item name="component" xsi:type="string">Magento_Ui/js/grid/columns/select</item>
                    <item name="editor" xsi:type="string">select</item>
                    <item name="dataType" xsi:type="string">select</item>
                    <item name="label" xsi:type="string" translate="true">Status</item>
                    <item name="sortOrder" xsi:type="number">100</item>
                </item>
            </argument>
        </column>
         <actionsColumn name="actions" class="Wundercarparts\Makeanoffer\Ui\Component\Listing\Column\OffersActions">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="indexField" xsi:type="string">offers_id</item>
                    <item name="sortOrder" xsi:type="number">200</item>
                </item>
            </argument>
        </actionsColumn>
    </columns> 
</listing>

di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Framework\View\Element\UiComponent\DataProvider\CollectionFactory">
        <arguments>
            <argument name="collections" xsi:type="array">
                <item name="offers_ui_listing_data_source" xsi:type="string">Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Collection</item>
            </argument>
        </arguments>
    </type>
    <type name="Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Collection">
        <arguments>
            <argument name="mainTable" xsi:type="string">wcp_offers</argument>
            <argument name="eventPrefix" xsi:type="string">offesr_ui_grid_collection</argument>
            <argument name="eventObject" xsi:type="string">offers_grid_collection</argument>
            <argument name="resourceModel" xsi:type="string">Wundercarparts\Makeanoffer\Model\ResourceModel\Offers</argument>
        </arguments>
    </type>
    <virtualType name="MenuGirdFilterPool" type="Magento\Framework\View\Element\UiComponent\DataProvider\FilterPool">
        <arguments>
            <argument name="appliers" xsi:type="array">
                <item name="regular" xsi:type="object">Magento\Framework\View\Element\UiComponent\DataProvider\RegularFilter</item>
                <item name="fulltext" xsi:type="object">Magento\Framework\View\Element\UiComponent\DataProvider\FulltextFilter</item>
            </argument>
        </arguments>
    </virtualType>
    <virtualType name="MenuGridDataProvider" type="Magento\Framework\View\Element\UiComponent\DataProvider\DataProvider">
        <arguments>
            <argument name="collection" xsi:type="object" shared="false">Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Collection</argument>
            <argument name="filterPool" xsi:type="object" shared="false">MenuGirdFilterPool</argument>
        </arguments>
    </virtualType>
</config>

Answer 1

Create a new class called Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Grid\Collection (place it in the proper file to match the file path).

The class should look like this

<?php
namespace Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Grid;

use Magento\Framework\Api\SearchCriteriaInterface;
use Magento\Framework\Api\Search\SearchResultInterface;
use Magento\Framework\DB\Adapter\AdapterInterface;
use Magento\Framework\Data\Collection\Db\FetchStrategyInterface;
use Magento\Framework\Data\Collection\EntityFactoryInterface;
use Magento\Framework\Event\ManagerInterface as EventManagerInterface;
use Magento\Framework\Model\ResourceModel\Db\AbstractDb;
use Magento\Framework\Api\Search\AggregationInterface;
use Psr\Log\LoggerInterface;
use Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Collection as OffersCollection;

class Collection extends OffersCollection implements SearchResultInterface
{
    /**
     * Aggregations
     * 
     * @var AggregationInterface
     */
    protected $aggregations;

    /**
     * constructor
     * 
     * @param EntityFactoryInterface $entityFactory
     * @param LoggerInterface $logger
     * @param FetchStrategyInterface $fetchStrategy
     * @param EventManagerInterface $eventManager
     * @param string $mainTable
     * @param string $eventPrefix
     * @param string $eventObject
     * @param string $resourceModel
     * @param AdapterInterface $connection
     * @param AbstractDb $resource
     * @param $model
     */
    public function __construct(
        EntityFactoryInterface $entityFactory,
        LoggerInterface $logger,
        FetchStrategyInterface $fetchStrategy,
        EventManagerInterface $eventManager,
        $mainTable,
        $eventPrefix,
        $eventObject,
        $resourceModel,
        AdapterInterface $connection = null,
        AbstractDb $resource = null,
        $model = 'Magento\Framework\View\Element\UiComponent\DataProvider\Document'
    )
    {
        parent::__construct($entityFactory, $logger, $fetchStrategy, $eventManager, $connection, $resource);
        $this->_eventPrefix = $eventPrefix;
        $this->_eventObject = $eventObject;
        $this->_init($model, $resourceModel);
        $this->setMainTable($mainTable);
    }


    /**
     * @return AggregationInterface
     */
    public function getAggregations()
    {
        return $this->aggregations;
    }

    /**
     * @param AggregationInterface $aggregations
     * @return $this
     */
    public function setAggregations($aggregations)
    {
        $this->aggregations = $aggregations;
    }


    /**
     * Retrieve all ids for collection
     * Backward compatibility with EAV collection
     *
     * @param int $limit
     * @param int $offset
     * @return array
     */
    public function getAllIds($limit = null, $offset = null)
    {
        return $this->getConnection()->fetchCol($this->_getAllIdsSelect($limit, $offset), $this->_bindParams);
    }

    /**
     * Get search criteria.
     *
     * @return \Magento\Framework\Api\SearchCriteriaInterface|null
     */
    public function getSearchCriteria()
    {
        return null;
    }

    /**
     * Set search criteria.
     *
     * @param SearchCriteriaInterface $searchCriteria
     * @return $this
     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
     */
    public function setSearchCriteria(SearchCriteriaInterface $searchCriteria = null)
    {
        return $this;
    }

    /**
     * Get total count.
     *
     * @return int
     */
    public function getTotalCount()
    {
        return $this->getSize();
    }

    /**
     * Set total count.
     *
     * @param int $totalCount
     * @return $this
     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
     */
    public function setTotalCount($totalCount)
    {
        return $this;
    }

    /**
     * Set items list.
     *
     * @param \Magento\Framework\Api\ExtensibleDataInterface[] $items
     * @return $this
     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
     */
    public function setItems(array $items = null)
    {
        return $this;
    }
}

then replace in di.xml this

<item name="offers_ui_listing_data_source" xsi:type="string">Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Collection</item>

with this

<item name="offers_ui_listing_data_source" xsi:type="string">Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Grid\Collection</item>

and this line

<type name="Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Collection"> 

with

<type name="Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Grid\Collection">

For this last line, if your Offers collection expects the parameters mainTable and others, instead of changing the line, duplicate the section that starts with <type name="Wundercarparts\Makeanoffer\Model\ResourceModel\Offers\Collection"> and then replace the line for the one you just cloned.