When defining custom symbols for your object extensions, you may want to enforce certain aspects of the symbol format, while allowing users some liberty to change others. If you open the Symbol Format dialog from a custom symbol in the Resource Editor, you can control the default format options for the symbol, and whether users can edit them, on a per-tab basis.
For example, you could extend the PDM table metaclass with a criteria to specify a custom symbol with a red border for tables that are anticipated to contain more than 1m records. You may want to enforce this border style for all such tables while allowing users to change the font, size, content, and other aspects of the symbol format.
When you access the Symbol Format dialog from a custom symbol in the Resource Editor, the following additional options are available at the top of each tab:
| Option | Description |
|---|---|
|
Apply format to symbols |
Specifies that the format options on the tab will be applied to custom symbols at creation time or whenever the appropriate criteria are met or the specified stereotype applied. If this option is not selected, the standard display preferences for the format options on the tab will be applied and users are free to modify them. |
|
Allow users to modify symbol format |
Specifies that users can modify the format options for the symbol and that any changes that are made will be respected in the event that the definition of the custom symbol is updated. If Apply format to symbols is selected and this option is unselected, then the format options specified on this tab cannot be changed by the user. |
Click the Advanced button to open the Customize Content dialog to add or removed properties from this tab (see Customizing Content Display Preferences).
For detailed information about extending objects and creating custom symbols for them, see Customizing and Extending PowerDesigner > Extension Files.