Oracle Apex - (Form|Page) (Field|Item)
About
An item (also called a field) is a HTML form elements such as text fields, select lists, and check boxes.
Every item has a session state value that can be referenced by a variable.
Articles Related
Variable
Name
Item names must:
- Be unique within an application.
- Not include quotation marks.
- Begin with a letter or a number, and subsequent characters can be letters, numbers, or underscore characters.
- Be case-insensitive.
- Should not exceed 30 characters. Items longer than 30 characters cannot be referenced using bind variable syntax.
- Cannot contain letters outside the base ASCII character set
By default, wizards prefix page item names with:
P<page no>_<item name>
Default
The default attribute on the Edit Page Item page. The default value is used when the item's value is not derived from session state and when the source value is NULL.
Source
Post Calculation Computation Example:
initcap(:P10_MY_ITEM);
Attributes
Item attributes affect the display of items on a page.
For example, these attributes can impact:
- where a label displays,
- how large an item is,
- and if the item displays next to or below the previous item.
| Attributes | Description |
|---|---|
| Sequence | Specify the display sequence for this component. The sequence determines the order of evaluation. |
| Prompt | Enter the label for this HTML form element. You may include HTML, JavaScript, and shortcuts. You can also use the substitution string #CURRENT_ITEM_NAME# to obtain the name of the item associated with this label. |
| Field Template | Determines the label template. Label templates enable you to define the user interface attributes in a central place and share that definition among many labels. |
| Region | Defines the region in which the item displays. All items must be in a region. |
| New Line | Determines whether this item displays on the same line as the previous item or whether it displays on the next line. Items are laid out in an HTML table. Select Yes to have an item display as the first field in a new row in the table. |
| New Field | If set to Yes, this item is rendered into its own HTML table cell which is the default. If set to No, the item is rendered into the same HTML table cell as the previous page item. Note that rendering into the same table cell looks more attached to the previous page item. |
| Width | Specifies the length (in characters) of the form element that displays for this item. |
| Height | Specifies the height (in lines) for text areas and multi select lists. |
| Column Span | Items are laid out in HTML tables. This property defines the value to be used for the COLSPAN attribute in the table cell. |
| Row Span | Items are laid out in HTML tables. The attribute determines the value to be used for the ROWSPAN attribute in the table cell that the item displays in. |
| Post Element | Text or HTML code is rendered immediately after the page item element. |
Type
built-in
- text fields,
- text areas,
- password,
- radio groups,
- select lists,
- check boxes,
- date pickers,
- and popup list of values
Specific
Developers can create their own custom item types using plug-ins.
Level
There are two types of items:
- page items
- and application items.
In the session windows, you can see them:
Page
Page items are placed on a page and have associated user interface properties, such as:
- Display Only,
- Label
- and Label Template.
Examples of page-level items include a check box, date picker, display as text, file browse field, popup list of values, select list, or a text area.
Application
Application items are not associated with a page and therefore have no user interface properties.
Security
Oracle Apex - Security Configuring page item security
Management
Initialization
Oracle Apex - Item (Initialization | Evaluation | Populating | Computation)
Bulk Editing
You can use the Page Items page to edit the sequence, field label, template, region, and overall position for all items on a page.
Scripting
You can use the APEX_ITEM package to create form elements dynamically based on a SQL query instead of creating individual items page by page.