Adding Field to Text Programmatically

By Madhukar Moogala

We will see in this blog how can we set the contents of a AcDbText entity to a field linking to contents of another AcDbText.

Two APIs to be noted here,

1. AcFdMakeFieldCode, formats an object property field code using the specified components.
2. acdbEvaluateFields,evaluates all the fields in the objects in the database, similar to UpdateFields in the UI.

CString sPrompt(_T("nSelect entity: "));    ads_name  an;    ads_point ap;    int nReturn = acedEntSel(sPrompt, an, ap);    // Canceled or nothing selected    if (nReturn == RTCAN)    {    return;    }         // Convert ads name to object id    AcDbObjectId id;    acdbGetObjectId(id, an);         AcTransaction* pTrans = acdbTransactionManager->startTransaction();    if (NULL == pTrans)    {    return;    }         AcDbText* pExistingText = NULL;    Acad::ErrorStatus es = acdbTransactionManager->getObject((AcDbObject*&)pExistingText, id, AcDb::kForRead);    if (!eOkVerify(es))    {    acdbTransactionManager->abortTransaction();    acedPrompt(_T("nNot a text"));    return;    }         AcDbText* pText = new AcDbText();    pText->setPosition(    AcGePoint3d(pExistingText->position().x,    pExistingText->position().y+20.00,    pExistingText->position().z));    ads_name objName;    acdbGetAdsName(objName, id);              ACHAR* strField;    AcFdMakeFieldCode(id,(AcDbEvalNodeId)0,                        _T("TextString"),                        AcFdEval::kObjFieldNone,                        _T(""),                        (AcHyperlink*)NULL,                        (ACHAR*&)strField);     pText->setTextString(strField);          AcDbBlockTableRecord* pModelSpace = NULL;    es = acdbTransactionManager->getObject((AcDbObject*&)pModelSpace,    acdbSymUtil()->blockModelSpaceId(    acdbHostApplicationServices()->workingDatabase()),    AcDb::kForWrite);         if (!eOkVerify(es))    {    acdbTransactionManager->abortTransaction();    acedPrompt(_T("nCannot open model space."));    return;    }         AcDbObjectId outId;    es = pModelSpace->appendAcDbEntity(outId, pText);    if (!eOkVerify(es))    {    acdbTransactionManager->abortTransaction();    acedPrompt(_T("nCannot append new entity."));    return;    }    pText->close();    /*Update Fields*/    es = acdbEvaluateFields(outId,    AcDbField::kRegen,    NULL,    acdbHostApplicationServices()->workingDatabase(),    AcFd::kEvalRecursive);    if(!eOkVerify(es))    {    CString esText = acadErrorStatusText(es);    esText = esText + _T(":
Failed to Evalute");    acedAlert(esText);    }    /*Clean Up*/    acutDelString(strField);    acdbTransactionManager->endTransaction();