Package org.apache.tapestry5.services

## Interface PersistentFieldBundle

- All Known Implementing Classes:
    `PersistentFieldBundleImpl`

      public interface PersistentFieldBundle

  Encapsulates persisted property information for an entire page.

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `boolean` | `containsValue​(String componentId, String fieldName)` | Checks to see if a persistent value has been stored for the indicated component and field.
    `Object` | `getValue​(String componentId, String fieldName)` |

- - ### Method Detail

    - #### containsValue

          boolean containsValue​(String componentId,
                                String fieldName)

      Checks to see if a persistent value has been stored for the indicated component and field. TODO: This method can probably be removed; it doesn't look like its used (instead, we if check getValue() returns null).
      Parameters:
        `componentId` - the nested id of the component (within the page), may be null or blank for the root component of the page
        `fieldName` - the name of the field whose value was persisted
      Returns:
        true if a change has been stored

    - #### getValue

          Object getValue​(String componentId,
                          String fieldName)

      Parameters:
        `componentId` - the nested if of the component (within the page), may be null or blank for the root component of the page
        `fieldName` - the name of the field whose value was persisted
      Returns:
        the persisted value, possibly null