Adding or Changing Object Data

Traversing Object Data

Object Data Samples

Coordinate Systems

 

Adding or Changing Object Data

The structure for containing data in an object data table is a table record (AcMapOdTableRecord object).

The actual data in the record is contained in instances of the AcMapValue class, one value for each field (column) in the record. You read the value of a record using one form of AcMapODTableRecord::Value, and you add new data or modify the existing value, using the other form, which is the non-const override of the function.

The following sample shows how to add new data or modify the current data in the object records of selected objects. Before performing this procedure, create a table named Zones. Next, attach data. Data attached to selected objects consists of two columns: a zoning code column called Code and an Approved By column.

To add or change object data

1. Include the necessary header files:

   #include "StdAfx.h"
   #include "StdArx.h"
   #include <MapODColumn.h>
   #include <MapArxApi.h>
   #include <MapODDefinition.h>
   #include <MapProj.h>
   #include <MapODRecord.h>
   #include <MapODIterator.h>
   

2. Define a constant for input of the record values and declare variables.

   #define USR_STRG_LENGTH 133
   int retCode = FALSE;
   ads_name ename;
   ads_point spt;
   char zoneCode [USR_STRG_LENGTH] = "";
   char approveCode [USR_STRG_LENGTH] = "";
   AcMapSession *mapApi = NULL;
   AcMapProject *pProj = NULL;
   AcMapODContainer *pODCont = NULL;
   AcMapODRecordIterator *pIter = NULL;
   AcDbObjectId eId;
   AcMapODTableRecord record;

3. Create an AutoCAD Map 3D session and get the top level objects.

   mapApi = AcMapGetSession();
   mapApi->GetProject(pProj);
   pProj->GetODContainer(pODCont);

4. Use ADS functions to prompt user to select an object, and convert the entity name of the selected object to an object ID for initializing the iterator in the next step.

   retCode = acedEntSel(NULL, ename, spt); 
   if (retCode != RTNORM) {
   acutPrintf("\nNo object selected.\n"); 
   return;} 
   acdbGetObjectId(eId, ename);

5. Get a record iterator and initialize it for writing. Using the iterator in a for loop, traverse the records of the object selected in step 4, getting the table associated with each record.

   pODCont->GetObjectODRecordIterator (pIter);
   pIter->Init (eId, AcMap::kOpenForWrite, Adesk::kFalse);
   for (; pIter->IsDone() == Adesk::kFalse; pIter->Next())
   {
   pIter->GetRecord (record); 
   pODCont->GetODTable (pTable, record.ODTableName()); 
   acutPrintf("\n*** OD Table %s.", record.ODTableName()); 

6. Loop through the columns of each record, and print the name of the column, which in this example is either Code or Approved By.

   for (int i = 0; i < record.Count(); i++) 
   { 
   AcMapODTableDefinition tableDef = pTable->Definition(); 
   AcMapODColumnDefinition Column; 
   tableDef.GetColumn(Column, i); 
   acutPrintf("\n%-15s", Column.Name()); 

7. Print the value at the column of the record and get a pointer, colname, to the column.

   AcMapValue &val = record.Value(i); 
   acutPrintf(" %s", ((const char *)val)); 
   colname = Column.Name(); 

8. Create an AcMapValue variable and assign the value entered by the user to it. Then, assign the AcMapValue variable to the value of the record using the AcMapODTableRecord::Value function. Update the record using the record iterator.

   if(!strcmp(colname, "Code")){ 

   acedGetString(TRUE,"\nNew zoning code:", zoneCode); 

   AcMapValue v = zoneCode; 

   record.Value(i) = v; 

   pIter->UpdateRecord(record); 

   } 

9. Using the same paradigm as step 9, get and update the record's Approved by column.

   if(!strcmp(colname, "Approved")){ 

   acedGetString(TRUE,"\nApproved by:", approveCode); 

   AcMapValue v = approveCode; 

   record.Value(i) = v; 

   pIter->UpdateRecord(record); 

   } 

10. End the for loop started in step 7 and delete the pointer to the table created with AcMapODContainer::GetODTable. End the for loop started in step 6 and delete the iterator created in step 5.

    }//end for 
    if (pTable) delete pTable; 
    } //end for 
    if (pIter) delete pIter;