Add or Edit Category

Use this backend screen to create a JEM category or maintain an existing one. Categories organise events, form parent-and-child structures, control frontend access, can assign JEM maintainers, and can provide colours, types, images, notifications and associated Joomla article rules.

Plan the category before assigning events. Access, maintainer groups, associated-article settings and default images affect how new events in the category are created and managed.

Navigation and Permissions

In the Joomla administrator, select Components → JEM → Categories, then select New. To edit an existing category, select its name in the Categories list.

Creating a category requires the applicable JEM create permission. Editing an existing category requires permission for that category. Toolbar actions are hidden when the administrator lacks the required permission or when another user has checked out the record.

Toolbar

ActionResultAvailability
Save Saves the category and keeps the edit form open. Requires permission to create or edit the category.
Save & Close Saves the category and returns to the Categories list. Shown in Joomla's grouped Save actions.
Save & New Saves the category and opens a new empty category form. Requires category-create permission.
Save as Copy Creates an independent category based on the current one and generates a unique name and alias. Available when editing and the user can also create categories.
Cancel / Close Leaves the form without saving unsaved changes. Displays Cancel for a new category and Close for an existing category.
Toggle Inline Help Shows or hides Joomla inline field help. Available from the toolbar.
Help Opens the related JEM help page. Available from the toolbar.

Screen Layout

AreaContents
Main area Category identity, hierarchy, status, access, colour, type, Joomla article association and description.
Side panels Publishing Options, Category emails, Group, Image and Metadata Information.

Recommended Category Workflow

1. Structure
Choose the name and parent.
2. Visibility
Set status and Access.
3. Workflow
Assign a maintainer group.
4. Integration
Configure Joomla articles and mail.
5. Display
Select colour, type and image.
6. Verify
Save and test with the intended user.

Category Details

FieldPurposeRules and notes
Category The public name of the category. Required. Use a concise name that distinguishes the events assigned to it.
Alias The URL-safe value used by Joomla routing. Leave empty to generate it from the category name. Aliases must be unique among categories with the same parent.
Parent Places this category below another category. Select the root option for a top-level category. Moving a parent also moves its descendants within the hierarchy.
Status Controls the category's publication state. Available values are Published, Unpublished, Archived and Trashed. Normal frontend output uses published categories.
Access The Joomla viewing access level required to see the category and its category-controlled output. This controls frontend visibility. It does not make a user a JEM maintainer and does not by itself grant backend editing permission.
Colour A category-specific colour used by calendars, category labels and compatible modules or layouts. Use Joomla's colour selector or leave it empty. The exact use of the colour depends on the view or module configuration.
Type Assigns a JEM type configured for Categories. A category type can provide a translated label, description, icon and colour to compatible views and maps.
Joomla Category Selects the Joomla Content category in which associated articles for this JEM category are created. Required when Article Mode is Automatic. It is also the allowed/default destination for Create on demand.
Article Mode Controls the associated Joomla article workflow for events assigned to this category. Choose No associated article, Create on demand or Automatic. See the detailed section below.
ID The read-only database identifier. A new category receives its ID after the first save.
Description The main category text entered with Joomla's configured editor. Optional. It is displayed by category layouts that enable the category description; safe HTML is accepted.

Category Hierarchy

JEM categories form a tree. A category can be top-level or a child of another category, and it can itself contain child categories. The hierarchy supports organised menus and category views, but whether a view includes events from descendants depends on that view's Include subcategories option.

Example hierarchy
  • Music
    • Classical
    • Jazz
    • Rock

Use the category list's ordering and batch tools for larger reorganisations. JEM rebuilds the internal tree path when a category is saved or moved.

Access, Maintainer Group and Administrator Permissions

These controls solve different problems and should not be treated as interchangeable:

ControlWho it affectsWhat it controls
Access Frontend visitors in Joomla viewing access levels Who may see the category and category-protected output.
Group Members of the selected JEM maintainer group Which frontend maintainers can select and work with the category, according to that JEM group's Add Event, Edit Event and Publish Event rights.
JEM/Joomla permissions Backend or frontend users covered by Joomla ACL rules Whether the user can create, edit, change state or delete records. These rules are configured in JEM Options and Joomla user permissions, not in a separate visible panel on this form.
A higher Access level does not grant editing rights. Conversely, a maintainer may be allowed to submit or edit an event but still be unable to see frontend output whose Joomla viewing access level excludes that user.

Associated Joomla Articles

JEM can link an event to a Joomla Content article. The category fields establish whether that workflow is available and which Joomla article category is used.

Article ModeBehaviourJoomla Category
No associated article This JEM category does not request article creation for its events. Not required.
Create on demand The event editor can choose to create an associated article when saving the event. Select the permitted/default Joomla Content category.
Automatic JEM creates the associated article automatically according to the event and global article options. Required; the category cannot be saved in Automatic mode without it.

If an event belongs to several JEM categories that point to different Joomla categories, the event form may require the editor to select the intended destination. Existing associated articles are validated against the active category associations.

Article access, copied images, event-date use, recurrence behaviour and other article contents are controlled by the associated-article options in JEM and the event form.

Publishing Options Panel

FieldPurpose
Created by The Joomla user recorded as the category creator. Administrators with the necessary permission can select another user.
Created date The read-only creation timestamp, shown after the category has been created.
Modified by The read-only user who last modified the category, shown after a modification exists.
Modified date The read-only most recent modification timestamp.

Category Emails Panel

FieldPurposeNotes
Email(s) Notification recipients associated with this category. Enter one or more valid comma-separated addresses. Invalid and duplicate addresses are removed by the mailer.
Send email to user of this Access Level Adds active Joomla users belonging to the groups contained in this category's viewing access level as recipients. This can notify many users. Review the selected Access level and its Joomla user groups before enabling it.

Actual delivery also depends on the JEM Mailer plugin being enabled and configured to send the relevant event creation or modification notification to category or category-ACL recipients.

Group Panel

Select a JEM group to make its members the maintainers of this category, or select No Group. The group's own permissions determine whether members can add, edit or publish events. If a previously assigned group no longer exists, JEM identifies it as an unknown group so the category can be corrected.

A category group can also be used as a recipient source when the JEM Mailer plugin is configured to notify category maintainer groups.

Image Panel

FieldPurposeNotes
Image Selects or uploads the category image stored in JEM's category image folder. Category and event layouts display it only when their image options are enabled.
Use as default event image Uses this category image for new events in the category when they have no event image. JEM copies the image into its event image folder. For an event with several categories, the first selected category with this option and an image supplies the default.

The default image is assigned only while creating a new event without an image. Later category-image changes do not retroactively replace images already assigned to existing events.

Colour, Type and Map Icon Behaviour

The category's own Colour is used by calendars, labels and modules that support category colours. A Category Type can additionally provide a type name, icon and colour.

For an event marker in Events Map, the type-icon priority is:

  1. Event Type icon and its Type colour;
  2. Category Type icon and its Type colour;
  3. Venue Type icon and its Type colour;
  4. The globally or locally configured default map marker.

When an event has several categories, the first assigned category with a suitable Category Type is used by the map query. The category's direct colour and the Category Type colour are separate settings: the active view or module decides which one is used for labels, calendar styling or markers.

Metadata Information Panel

FieldPurpose
Meta Description A concise description for search engines and integrations. It should summarise the category without duplicating a long description.
Meta Keywords Optional comma-separated keywords associated with the category.

Practical Examples

  1. Enter the category name and choose its parent.
  2. Set Status to Published and Access to Public.
  3. Create a JEM group containing the trusted maintainers and enable its required event rights.
  4. Assign that group in the category's Group panel.
  5. Log in as a maintainer and verify that the category is available in the frontend event form.

  1. Create the destination category in Joomla Content.
  2. Select it in Joomla Category.
  3. Set Article Mode to Automatic.
  4. Save the JEM category, then create a test event assigned to it.
  5. Verify the associated article's category, access, content, image and recurrence behaviour.

  1. Select or upload an Image for the category.
  2. Enable Use as default event image and save.
  3. Create a new event without selecting an event image and assign this category.
  4. Save and confirm that the copied category image is now the event image.
  5. Repeat with an explicit event image to confirm that the event image takes priority.

  1. Create a JEM Type that applies to Categories and assign it an icon and colour.
  2. Assign the type to this category.
  3. Create an event in the category without an Event Type icon and use a venue without a Venue Type icon.
  4. Open Events Map and verify that the Category Type icon and colour are used.

Troubleshooting

SymptomWhat to check
The category cannot be saved Confirm that Category is present. If Article Mode is Automatic, select a valid Joomla Category. Also check permission, checkout and alias conflicts under the same parent.
The category is not visible on the frontend Check Status, Access, the visitor's Joomla viewing groups, menu/view category filters and whether the parent view includes subcategories.
A maintainer cannot select the category Confirm that the user is a member of the assigned JEM Group and that the group has the necessary Add Event or Edit Event permission. Access and Group are independent.
The event has no associated Joomla article Check Article Mode, the selected Joomla Category, the event's article action and global associated-article options. With several JEM categories, resolve any destination-category choice.
The default event image is not assigned The feature applies only to new events with no image. Confirm that the category has an image, the option is enabled and this is the first qualifying selected category.
Category notification mail is not sent Check the JEM Mailer plugin, its recipient settings, Joomla mail configuration, valid category addresses and the groups contained in the selected Access level.
The expected colour is not displayed Check whether the current view or module supports category colours, its colour mode, the direct Category colour and the Category Type colour.
The Category Type icon is not used on Events Map Confirm that the type applies to Categories and has a valid icon. An Event Type icon has higher priority; the selected category order can also matter.
A child category's events are missing from its parent view Enable the view or menu item's Include subcategories option where available.

Technical Notes

  • Categories are stored as a nested-set tree in #__jem_categories. JEM rebuilds the category path and descendant tree values after structural changes.
  • An alias is generated from the category name when empty and must be unique within the same parent category.
  • Event-to-category assignments are stored in #__jem_cats_event_relations; one event can belong to several categories.
  • Associated Joomla article settings use article_category_id and article_create_mode. Automatic mode is rejected when no Joomla Content category is selected.
  • When category default-image mode is enabled, JEM copies the category image to its event-image location and assigns it only to qualifying new events.
  • Category notification addresses, Joomla access-level recipients and JEM group recipients are resolved independently by the JEM Mailer plugin and then deduplicated.
  • Category types are restricted to the Category entity. Events Map resolves marker icons in Event Type, Category Type, Venue Type and configured-default order.
  • The form uses Joomla session-token validation, record checkout, safe HTML filtering for the description and permission-aware toolbar actions.

Related Documentation

  • Categories — manage, filter, order, publish and batch-process categories.
  • Add or Edit Group — configure category maintainers and their event rights.
  • Add Event — assign categories, images, types and associated Joomla articles.
  • Categories — available frontend category views and menu items.
  • Events Map — marker configuration and Type icon priority.
  • Multilingual Event Content Articles — use associated Joomla articles for multilingual event content.

Related GitHub Issues