Changes between Version 3 and Version 4 of FDORfc60


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Timestamp:
04/13/11 07:39:01 (14 years ago)
Author:
gregboone
Comment:

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  • FDORfc60

    v3 v4  
    4343Annotation text can include text on maps derived from vector information, or text overlays for imagery for information not discernable from the image, such as place or street names. In most cases, applications that do this have certain rules for creating and re-creating text based on the dynamic view of the mapping application. While this standard is not targeted to those usages, there are some allowances for this type of storage if it is so desired. In particular, it is allowable to store text that does not scale with the map objects but instead has a fixed display size (expressed as “points”, 72 to the inch). However, there are some limitations on this usage particularly with spatial indexing.
    4444
    45 === Text Entities ===
    46 
    4745A text object consists of an ordered list of independently placed text elements, possibly corresponding to individual lines of text in a multiline text display, and an envelope that approximates an outer limit of the text elements when placed. Each element has its own text attributes, but they are not used independently. The first element may set the attribute for all following elements and subsequent elements text attributes are only specified when a change is required. This behavior just extends that of the metadata text attributes to each element of the array.
    4846
     
    5149== Proposed Solution ==
    5250
     51=== Supporting Annotations in Existing (Non-FDO) Schema ===
     52
     53In order for the FDO API to be able to detect and support Annotation defined in existing schemas such as Oracle, the schema being read must support the Annotation metadata tables as mandated by the OGC Simple Feature Access Specification. The metadata can be exposed as a set of tables or views.
     54
     55==== OGC Annotation Metadata Table ====
     56
     57As specified in the OGC Simaple Access Specification, the following CREATE TABLE statement creates an appropriately structured table to be included in the schema, describing how text is stored in a feature table. This should be either an actual metadata table or an updateable view.
     58
     59There is no requirement that the annotated feature have any other attributes. Unattributed annotations are in essence context-free, and may be used to place any text on the data, such as collection metadata or notes to user about unusual situations of which he may wish to be aware.
     60
     61{{{
     62CREATE TABLE ANNOTATION_TEXT_METADATA AS
     63{
     64    F_TABLE_CATALOG AS CHARACTER VARYING NOT NULL,
     65    F_TABLE_SCHEMA AS CHARACTER VARYING NOT NULL,
     66    F_TABLE_NAME AS CHARACTER VARYING NOT NULL,
     67    F_TEXT_KEY_COLUMN AS CHARACTER VARYING NOT NULL,
     68    F_TEXT_ENVELOPE_COLUMN AS CHARACTER VARYING NOT NULL,
     69    A_ELEMENT_TABLE_CATALOG AS CHARACTER VARYING NOT NULL,
     70    A_ELEMENT_TABLE_SCHEMA AS CHARACTER VARYING NOT NULL,
     71    A_ELEMENT_TABLE_NAME AS CHARACTER VARYING NOT NULL,
     72    A_ELEMENT_TEXT_KEY_COLUMN AS CHARACTER VARYING NOT NULL
     73    A_ELEMENT_TEXT_SEQ_COLUMN AS CHARACTER VARYING NOT NULL
     74    A_ELEMENT_TEXT_VALUE_COLUMN AS CHARACTER VARYING NOT NULL,
     75    A_ELEMENT_TEXT_LEADERLINE_COLUMN AS CHARACTER VARYING NOT NULL,
     76    A_ELEMENT_TEXT_LOCATION_COLUMN AS CHARACTER VARYING NOT NULL,
     77    A_ELEMENT_TEXT_ATTRIBUTES_COLUMN AS CHARACTER VARYING NOT NULL,
     78    A_TEXT_DEFAULT_EXPRESSION AS CHARACTER VARYING,
     79    A_TEXT_DEFAULT_ATTRIBUTES AS CHARACTER VARYING
     80}
     81}}}
     82
    5383TBD
     84
    5485
    5586== Implications ==