An Ext plugin changes Liferay DXP itself when the plugin is deployed; it’s not a separate component that you can easily remove at any time. For this reason, the Ext plugin development process is different from other project types. It’s important to remember that once an Ext plugin is deployed, some of its files are copied inside the Liferay installation; the only way to remove the changes is by redeploying an unmodified Liferay DXP application. You’re also responsible for checking that patches and fix packs do not conflict with your Ext plugin. Additionally, Ext plugins aren’t hot deployable. To deploy an Ext plugin, you must restart your server. Additional steps are also required to deploy or redeploy to production systems.
It’s strongly recommended to only develop/deploy one Ext plugin. This means that
all your customizations should live inside one Ext plugin. Liferay Workspace
does not check for conflicts among multiple Ext plugins stored in the /ext
folder, so do not develop/deploy multiple Ext plugins at once.
You can deploy and redeploy your Ext plugin during your development phase. Redeployment involves manually removing the Ext plugin and cleaning your application server (i.e., remove it ); this is recommended so any changes made to the Ext plugin during development are properly applied, and files removed from your plugin by previous changes aren’t left behind in the Liferay DXP application. Because of this added complexity, you should use another plugin type to accomplish your goals whenever possible.
Now it’s time to set up the build environment.
Set Up the Build Environment
If you’re leveraging
Liferay Workspace,
you should create/develop your Ext module project in the /ext folder
(default); you can specify a different Ext folder name in workspace’s
gradle.properties by adding
liferay.workspace.ext.dir=EXT_DIR
If you are developing an Ext module project in standalone mode (not associated
with Liferay Workspace), you must declare the Ext Gradle plugin in your
build.gradle:
apply plugin: 'com.liferay.ext.plugin'
Next you’ll explore an Ext plugin’s advanced configuration files.
Using Advanced Configuration Files
Liferay DXP uses several internal configuration files for its own architecture; in addition, there are configuration files for the libraries and frameworks Liferay DXP depends on (e.g., Spring). Configuration could be accomplished using fewer files with more properties in each, but maintenance and use is made easier by splitting up the configuration properties into several files. For advanced customization needs, it may be useful to override the configuration specified in multiple configuration files. Liferay DXP provides a clean way to do this from an Ext plugin without modifying the original files.
All the configuration files in Liferay DXP are listed below by their path in an Ext plugin folder. Here are descriptions of what each file is for and the path to the original file in Liferay DXP:
extImpl/resources/META-INF/ext-model-hints.xml- Description: Overrides the default properties of the fields of the data models used by Liferay DXP’s core portlets. These properties determine how the form fields for each model are rendered.
- Original file in Liferay DXP:
portal-impl/src/META-INF/portal-model-hints.xml
extImpl/resources/META-INF/ext-spring.xml- Description: Overrides the Spring configuration used by Liferay DXP and any of its core portlets. It’s most commonly used to configure specific data sources or swap the implementation of a default service with a custom one.
- Original file in Liferay DXP:
portal-impl/src/META-INF/*-spring.xml
extImpl/resources/META-INF/portal-log4j-ext.xml- Description: Allows overriding the Log4j configuration. It can be used
to configure appenders for log file location, naming, and rotation. See
the
Log4j XML Configuration Primer.
Increasing or decreasing the log level of a class or class hierarchy
is best done outside of an Ext plugin, in Liferay DXP’s’ UI or a Log4j XML
file in a module or the
osgi/log4jfolder. - Original file in Liferay:
portal-impl/src/META-INF/portal-log4j.xml
- Description: Allows overriding the Log4j configuration. It can be used
to configure appenders for log file location, naming, and rotation. See
the
Log4j XML Configuration Primer.
Increasing or decreasing the log level of a class or class hierarchy
is best done outside of an Ext plugin, in Liferay DXP’s’ UI or a Log4j XML
file in a module or the
ext-web/docroot/WEB-INF/portlet-ext.xml- Description: Overrides the core portlets’ declarations. It’s most commonly used to change the init parameters or the roles specified.
- Original file in Liferay DXP:
portal-web/docroot/WEB-INF/portlet-custom.xml
ext-web/docroot/WEB-INF/liferay-portlet-ext.xml- Description: Overrides the Liferay-specific core portlets’ declarations. It core portlets included in Liferay DXP. Refer to the liferay-portlet-app_7_0_0.dtd file for details on all the available options. Use this file with care; the code of the portlets may be assuming some of these options to be set to certain values.
- Original file in Liferay DXP:
portal-web/docroot/WEB-INF/liferay-portlet.xml
ext-web/docroot/WEB-INF/liferay-display.xml- Description: Overrides the portlets that are shown in the interface for adding applications and the categories in which they’re organized.
- Original file in Liferay DXP:
portal-web/docroot/WEB-INF/liferay-display.xml
Next you’ll deploy your Ext plugin.