Nuclos generic implementation tutorial: GenericBusinessObject, generic BO, replace instanceof, rule, number range, sum calculation, mapping.

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Tutorial: generic implementation

Hands-on tutorial for generic implementation – one abstract BO and one rule for many concrete BOs (number ranges, sum calculation).

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Goal: create a generic business object and implement a generic rule.
Prerequisite: at least two business objects with similar fields (e.g. a running number).

The generic implementation replaces repeated rule code branched by instanceof with one abstract BO serving several concrete BOs.

Example 1: number ranges

Several BOs (quote, order, delivery note, purchase order) receive an automatic number on creation. Previously solved via instanceof:

public void insert(InsertContext context) throws BusinessException {
        final Modifiable<?> businessObject = context.getBusinessObject(Modifiable.class);
        if (businessObject instanceof Angebot) {
            ((Angebot) businessObject).setAngebotsnr(NummernkreiseLogik.getNextValue(Angebot.class));
        } else if (businessObject instanceof Auftrag) {
            ((Auftrag) businessObject).setAuftragsnr(NummernkreiseLogik.getNextValue(Auftrag.class));
        } else if (businessObject instanceof Lieferschein) {
            ((Lieferschein) businessObject).setLieferscheinnr(NummernkreiseLogik.getNextValue(Lieferschein.class));
        } else if (businessObject instanceof Bestellung) {
            ((Bestellung) businessObject).setBestellnr(NummernkreiseLogik.getNextValue(Bestellung.class));
        } 
    }

1. Create the generic BO

Create a new generic BO Nummerierbar in the business object wizard with exactly one attribute Nummer (no layout/permissions) and assign it to a nuclet.

The data type of the generic attribute must match that of the fields in the implementing BOs.

2. Configure the mapping

For each implementing BO create a record with the attribute mapping (e.g. Nummer → order number). Nuclos generates the class Nummerierbar.java with generic getters/setters:

import org.nuclos.businessentity.*; 
import org.nuclos.api.businessobject.Dependent; 
import org.nuclos.api.businessobject.Flag; 
import org.nuclos.api.UID; 
import org.nuclos.api.businessobject.GenericBusinessObject; 
import java.util.List; 
import java.util.ArrayList; 
import java.util.HashSet; 
/**
 * BusinessObject: Nummerierbar
 *<br>
 *<br>Nuclet: org.nuclet.tulteclico
 *<br>DB-Name: [generic]
 *<br>Editable: true
 *<br>Localized: false
 *<br>Statemodel: false
**/
public class Nummerierbar implements GenericBusinessObject<Long> {
private org.nuclos.api.businessobject.BusinessObject<Long> businessObject;
public Nummerierbar(org.nuclet.tulteclico.Lieferschein businessObject) {
    this.businessObject = businessObject;
}
public Nummerierbar(org.nuclet.tulteclico.Bestellung businessObject) {
    this.businessObject = businessObject;
}
public Nummerierbar(org.nuclet.tulteclico.Auftrag businessObject) {
    this.businessObject = businessObject;
}
public Nummerierbar(org.nuclet.tulteclico.Angebot businessObject) {
    this.businessObject = businessObject;
}
public org.nuclos.api.UID getEntityUid() {
        return businessObject.getEntityUid();
}
public org.nuclos.api.businessobject.BusinessObject<Long> getBusinessObject() {
        return businessObject;
}
public java.lang.String getEntity() {
        return businessObject.getEntity();
}
public java.lang.Long getId() {
        return businessObject.getId();
}
public java.lang.Integer getVersion() {
        return businessObject.getVersion();
}
public boolean isInsert() {
        return businessObject.isInsert();
}
public boolean isUpdate() {
        return businessObject.isUpdate();
}
public boolean isDelete() {
        return businessObject.isDelete();
}
/**
 * Getter-Method for attribute: changedAt
 *<br>
 *<br>Entity: Nummerierbar
 *<br>DB-Name: DATCHANGED
 *<br>Data type: org.nuclos.common2.InternalTimestamp
 *<br>Localized: false
 *<br>Output format: null
 *<br>Scale: null
 *<br>Precision: null
**/
public java.util.Date getChangedAt() {
    // all implemented BOs:
    if (this.businessObject instanceof org.nuclet.tulteclico.Lieferschein) {
        return ((org.nuclet.tulteclico.Lieferschein) this.businessObject).getChangedAt();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Bestellung) {
        return ((org.nuclet.tulteclico.Bestellung) this.businessObject).getChangedAt();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Auftrag) {
        return ((org.nuclet.tulteclico.Auftrag) this.businessObject).getChangedAt();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Angebot) {
        return ((org.nuclet.tulteclico.Angebot) this.businessObject).getChangedAt();
    }
    // not implemented attribute:
    return null;
}
/**
 * Getter-Method for attribute: changedBy
 *<br>
 *<br>Entity: Nummerierbar
 *<br>DB-Name: STRCHANGED
 *<br>Data type: java.lang.String
 *<br>Localized: false
 *<br>Output format: null
 *<br>Scale: 255
 *<br>Precision: null
**/
public java.lang.String getChangedBy() {
    // all implemented BOs:
    if (this.businessObject instanceof org.nuclet.tulteclico.Lieferschein) {
        return ((org.nuclet.tulteclico.Lieferschein) this.businessObject).getChangedBy();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Bestellung) {
        return ((org.nuclet.tulteclico.Bestellung) this.businessObject).getChangedBy();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Auftrag) {
        return ((org.nuclet.tulteclico.Auftrag) this.businessObject).getChangedBy();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Angebot) {
        return ((org.nuclet.tulteclico.Angebot) this.businessObject).getChangedBy();
    }
    // not implemented attribute:
    return null;
}
/**
 * Getter-Method for attribute: createdAt
 *<br>
 *<br>Entity: Nummerierbar
 *<br>DB-Name: DATCREATED
 *<br>Data type: org.nuclos.common2.InternalTimestamp
 *<br>Localized: false
 *<br>Output format: null
 *<br>Scale: null
 *<br>Precision: null
**/
public java.util.Date getCreatedAt() {
    // all implemented BOs:
    if (this.businessObject instanceof org.nuclet.tulteclico.Lieferschein) {
        return ((org.nuclet.tulteclico.Lieferschein) this.businessObject).getCreatedAt();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Bestellung) {
        return ((org.nuclet.tulteclico.Bestellung) this.businessObject).getCreatedAt();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Auftrag) {
        return ((org.nuclet.tulteclico.Auftrag) this.businessObject).getCreatedAt();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Angebot) {
        return ((org.nuclet.tulteclico.Angebot) this.businessObject).getCreatedAt();
    }
    // not implemented attribute:
    return null;
}
/**
 * Getter-Method for attribute: createdBy
 *<br>
 *<br>Entity: Nummerierbar
 *<br>DB-Name: STRCREATED
 *<br>Data type: java.lang.String
 *<br>Localized: false
 *<br>Output format: null
 *<br>Scale: 255
 *<br>Precision: null
**/
public java.lang.String getCreatedBy() {
    // all implemented BOs:
    if (this.businessObject instanceof org.nuclet.tulteclico.Lieferschein) {
        return ((org.nuclet.tulteclico.Lieferschein) this.businessObject).getCreatedBy();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Bestellung) {
        return ((org.nuclet.tulteclico.Bestellung) this.businessObject).getCreatedBy();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Auftrag) {
        return ((org.nuclet.tulteclico.Auftrag) this.businessObject).getCreatedBy();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Angebot) {
        return ((org.nuclet.tulteclico.Angebot) this.businessObject).getCreatedBy();
    }
    // not implemented attribute:
    return null;
}
/**
 * Getter-Method for attribute: nummer
 *<br>
 *<br>Attribute Information:<br>
 *<br>
 *<br>Entity: Nummerierbar
 *<br>DB-Name: [generic]
 *<br>Data type: java.lang.String
 *<br>Localized: false
 *<br>Output format: null
 *<br>Scale: 255
 *<br>Precision: null
**/
public java.lang.String getNummer() {
    // all implemented BOs:
    if (this.businessObject instanceof org.nuclet.tulteclico.Lieferschein) {
        return ((org.nuclet.tulteclico.Lieferschein) this.businessObject).getLieferscheinnr();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Bestellung) {
        return ((org.nuclet.tulteclico.Bestellung) this.businessObject).getBestellnr();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Auftrag) {
        return ((org.nuclet.tulteclico.Auftrag) this.businessObject).getAuftragsnr();
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Angebot) {
        return ((org.nuclet.tulteclico.Angebot) this.businessObject).getAngebotsnr();
    }
    // not implemented attribute:
    return null;
}
/**
 * Setter-Method for attribute: nummer
 *<br>
 *<br>Attribute Information:<br>
 *<br>
 *<br>Entity: Nummerierbar
 *<br>DB-Name: [generic]
 *<br>Data type: java.lang.String
 *<br>Localized: false
 *<br>Output format: null
 *<br>Scale: 255
 *<br>Precision: null
**/
public void setNummer(java.lang.String pNummer) {
    // all implemented BOs:
    if (this.businessObject instanceof org.nuclet.tulteclico.Lieferschein) {
        ((org.nuclet.tulteclico.Lieferschein) this.businessObject).setLieferscheinnr(pNummer);
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Bestellung) {
        ((org.nuclet.tulteclico.Bestellung) this.businessObject).setBestellnr(pNummer);
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Auftrag) {
        ((org.nuclet.tulteclico.Auftrag) this.businessObject).setAuftragsnr(pNummer);
    }
    if (this.businessObject instanceof org.nuclet.tulteclico.Angebot) {
        ((org.nuclet.tulteclico.Angebot) this.businessObject).setAngebotsnr(pNummer);
    }
}
 }

3. Generic rule

In the server rule manager create a rule on creation, assign it to all implementing BOs (order/conditions as usual) and, instead of instanceof, fetch the generic BO from the context:

public void insert(InsertContext context) throws BusinessException {
    Nummerierbar n = context.getBusinessObject(Nummerierbar.class);
    n.setNummer(NummernkreiseLogik.getNextValue(n.getEntityUid()));
}

Example 2: sum calculation in document positions

Quote, order and invoice each have a subform with positions and the rule total = unit price × quantity. Instead of doing this per BO, it is solved generically.

Two generic BOs

Beleg (document, totals),
Belegposition (unit price, quantity, total + reference to the document).

After mapping, Nuclos generates Beleg.java and Belegposition.java. The latter maps e.g. getMenge() to getPos() of the respective concrete BO and provides getBelegposition() as a list.

Generic rule

public void save(SaveContext context) throws BusinessException {
    Belegposition pos = context.getBusinessObject(Belegposition.class);
    BigDecimal einzel = pos.getEinzelpreis();
    Integer menge = pos.getMenge();
    if (einzel != null && menge != null) {
        pos.setGesamtpreis(einzel.multiply(new BigDecimal(menge)));
    }
}

The rule is assigned to all relevant position BOs – one implementation covers all document types.

Related pages

Generic implementation

Concept.

Öffnen →

Server rule manager

Rules.

Öffnen →