Using and Developing Query Managers

Query managers are used in <query> tags to execute queries which can be used in charts.

SAV Charts extension comes with an internal query manager named savcharts which can deal with TYPO3 database queries as well as queries from other databases.

Using the Query Manager

In the backend in list mode create a new record in a page or a folder.

../../_images/InternalQueryManager.png

Select Database if you need to access to an external database, fill the different fields and save.

Tip

You do not need to create a new database access if you only need to access to the current TYPO3 database.

../../_images/InternalQueryManagerNewDatabase.png

Select Query to create a query. Select a database (default is TYPO3 Database), fill the different clauses and save.

The following figure illustrates the query to display the number of pages per year.

../../_images/InternalQueryManagerNewQuery.png

Assuming that the new query has the id 1, the following flexform configuration displays a bar chart with the number of pages per year.

../../_images/barChartWithQueryFlexformConfiguration.png

In the Queries section, the default query manager savcharts is used. It calls the query whose uid is 1.

The Data section of the flexform overloads the template to display only a single barchart with the data provided by the query, as explained in the section Using Advanced templates.

Important

The flag Allow queries (Admin) must be set by an Admin user in the content flexform to execute queries.

Go to the frontend to display the resulting chart.

../../_images/barChartWithQueryInFrontEnd.png

Developing Your Query Manager

Query managers are implemented by means of hooks.The hook for the internal query manager is in Classes/Hooks/SavChartsQueryManager.php. This class extends the abstract class AbstractQueryManager (Classes/Hooks/AbstractQueryManager.php) which itself implements the interface QueryManagerInterface (Classes/Hooks/QueryManagerInterface.php).

You can develop your own query manager by providing a hook which must be added in the file ext_localconf.php of your extension.

Assuming that your vendor name is MyVendorName and your extension name is my_extension. Assuming also that you have written your manager as the class MyQueryManager in Classes/Hooks/MyQueryManager.php. Finally, assuming that you want to name your query manager myManager, you should add the following code in ext_localconf.php of your extension.

$TYPO3_CONF_VARS['EXTCONF'][$_EXTKEY]['queryManagerClass']['myManager'] = \MyVendorName\MyExtension\Hooks\MyQueryManager::class;