topic Re: Custom Constraint in Alfresco Archive

Custom Constraint

kbonnet — Wed, 26 Mar 2008 16:36:22 GMT

I'm a total newbie on the area of java. Nevertheless i wanted to try to create a custom constraint which implements databaselookups for a pick list. I found an example here on the forum.I was able to get the java code compiled with javac against the Alfresco SDK. The result was a compiled .class fil

Re: Custom Constraint

acis — Thu, 27 Mar 2008 16:12:23 GMT

Hi,

I recognize my custom constraint here

You should have posted in the same topic for further readers.

After compilation you should place your .class file in
<TOMCAT>/webapps/alfresco/WEB-INF/classes/org/contezza/customConstraints/

Don't forget to change connection parameters to the database and to create a table codelabel with 2 fields : code and label.

Good luck.

Re: Custom Constraint

kbonnet — Thu, 27 Mar 2008 16:19:07 GMT

Hi Acis,

Thanks for your reply! I have it running since 10 minutes

It wasnt clear to me that i needed to put my class in the WEB-INF/lib directory. I thought that putting in somewhere in the classpath would be sufficient. When i tried WEB-INF/lib, it started working.

I also, in the process of troubleshooting, made a .jar file of it. And since i dont like to tamper in the deflated alfresco.war code, i create an AMP-file for it, so that i can install it nicely.

Now i have everything to deploy new classes, i can start customizing your java code.

Thanks a lot!

Kind regards,

Koen Bonnet

Re: Custom Constraint

msvoren — Thu, 10 Apr 2008 13:56:11 GMT

Thanks! That was helpful!

and 1 more question.. Is it possible to, somehow, reload this list from database, each time I access this dropdown?

Because now, this list is static, in order to apply changes from database, i have to restart alfresco.

Any chance of making this more dynamical?

Re: Custom Constraint

acis — Tue, 15 Apr 2008 08:03:02 GMT

I didn't try but I think it's possible by overriding the getAllowedValues() method like :

public List getAllowedValues() {
      this.loadDB();
      super.getAllowedValues();
}‍‍‍‍

Re: Custom Constraint

robain — Mon, 21 Apr 2008 18:23:33 GMT

my question is how does "allowedLabels" in this code comes into the picture. I see that only allowed values are displayed on the properties page drop down list and the same after selection. do generators and converters come into play if i want to show both of them "label" and "values". Can anyone post a sample of the generator or describe how it is going to look like.

Thanks
Robain

Re: Custom Constraint

robain — Mon, 21 Apr 2008 18:37:28 GMT

To add to my previous comment where does getSelectItemList() method come into play. I dont see it in any of the extended classes or the interface. but where or how is this method utilized.

Thanks
Robain.

Re: Custom Constraint

acis — Mon, 28 Apr 2008 09:42:45 GMT

Hi robain !

Here is how it works :

Your defined a constraint : in that case we extended ListOfValuesConstraint to select the values from a database or anywhere else.

In your web-client-config-custom.xml you should have define that you want to display the property with the constraint.

<property-sheet>
<show-property name="tc:codestr" component-generator="ListOfValuesQueryGenerator" />
</property-sheet>‍‍‍

If you don't put the additional attribut "component-generator", Alfresco will use a list with the values as values and labels of the drop down list. But here we want to have values as values and labels as labels. So we have to create a component generator.

As you can see, I added an additional attribute "component-generator". This attribute means that when alfresco will display the property, it'll use ListOfValuesQueryGenerator to create the component. The Generator is a subclass of org.alfresco.web.bean.generator.TextFieldGenerator. You must override the createComponent and generate methods.
This componentGenerator will call getSelectedItems.

public UIComponent generate(FacesContext context, String id) {

     UIOutput component = (UIOutput)context.getApplication().createComponent(
      ComponentConstants.JAVAX_FACES_OUTPUT);
      component.setRendererType(ComponentConstants.JAVAX_FACES_TEXT);
      FacesHelper.setupComponentId(context, component, id);
      return component;
   }

   protected UIComponent createComponent(FacesContext context, UIPropertySheet propertySheet, PropertySheetItem item) {
      
      UIComponent component = null;
      
      if (propertySheet.inEditMode()) {
         
        ListOfValuesQueryConstraint constraint=this.getListOfValuesQuery(context, propertySheet, item);
         
         PropertyDefinition propDef = this.getPropertyDefinition(context, propertySheet.getNode(), item.getName());
         
         if (constraint != null && item.isReadOnly() == false && propDef != null && propDef.isProtected() == false) {
            component = context.getApplication().createComponent(UISelectOne.COMPONENT_TYPE);
            FacesHelper.setupComponentId(context, component, item.getName());
            
            UISelectItems itemsComponent = (UISelectItems)context.getApplication().createComponent("javax.faces.SelectItems");
            
            itemsComponent.setValue(constraint.getSelectItemList());
            
            component.getChildren().add(itemsComponent);
         }
      }
      else {
         component = generate(context, item.getName());
      }
      
      return component;
   }

protected ListOfValuesQueryConstraint getListOfValuesQuery(FacesContext context, UIPropertySheet propertySheet, PropertySheetItem item) {
     
     ListOfValuesQueryConstraint lovqConstraint = null;
      PropertyDefinition propertyDef = getPropertyDefinition(context, propertySheet.getNode(), item.getName());
      
      if (propertyDef != null) {

         List<ConstraintDefinition> constraints = propertyDef.getConstraints();
         for (ConstraintDefinition constraintDef : constraints) {
            
            Constraint constraint = constraintDef.getConstraint();
            if (constraint instanceof ListOfValuesQueryConstraint) {
               lovqConstraint = (ListOfValuesQueryConstraint)constraint;
               break;
            }
         }
      }
      
      return lovqConstraint;
   }
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Ok now the Edit mode will work perfectly. But the problem is to display the field in view mode. Alfresco will show the value and not the label. So here you have to use a converter.

In your generator add this :

protected void setupConverter(FacesContext context, UIPropertySheet propertySheet, PropertySheetItem property, PropertyDefinition propertyDef, UIComponent component) {
         
         super.setupConverter(context, propertySheet, property, propertyDef, component);
         
         if(!propertySheet.inEditMode() && propertyDef != null && component instanceof UIOutput) {
            ((UIOutput)component).setConverter(new ListOfValuesQueryConverter(this.getListOfValuesQuery(context, propertySheet, property)));
         }
      }‍‍‍‍‍‍‍‍

and create the converter

public class ListOfValuesQueryConverter implements Converter,StateHolder {
   
   private ListOfValuesQueryConstraint constraint;
   
   public ListOfValuesQueryConverter(ListOfValuesQueryConstraint constraint) {
      this.constraint=constraint;
   }
   
   public Object getAsObject(FacesContext context, UIComponent component, String value) throws ConverterException {
      return new Object();
   }
   
   public String getAsString(FacesContext context, UIComponent component, Object value) throws ConverterException {
      
      if(value instanceof String) {
         List<String> l = this.constraint.getAllowedValues();
            for(int i=0;i<l.size();i++) {
               if(l.get(i).equals((String)value)) {
                  return this.constraint.getAllowedLabels().get(i);
               }
            }
      }
      else if(value instanceof List) {
         String result="";
         List<String> l = this.constraint.getAllowedValues();
         for(String val : (List<String>)value) {
               for(int i=0;i<l.size();i++) {
                  if(l.get(i).equals(val)) {
                     result+=this.constraint.getAllowedLabels().get(i)+" ";
                     break;
                  }
               }
         }
         return result;
      }
      
      return new String();
   }
   
   public ListOfValuesQueryConverter() {}
   public Object saveState(FacesContext context) { return (Object)this.constraint; }
   public void restoreState(FacesContext context, Object state) { this.constraint=(ListOfValuesQueryConstraint)state; }
   public boolean isTransient() { return false; }
   public void setTransient(boolean newTransientValue) {}
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

we could have use the "converter=" attribute in the web-client-config-custom.xml but good luck to do it. I tried hard and it didn't work out.

Re: Custom Constraint

alex--70 — Sat, 02 Aug 2008 08:16:02 GMT

Escuse me for my english, when i compile the 'customConstraints' i need to import the following :

import org.alfresco.repo.dictionary.constraint.ListOfValuesConstraint;
import org.alfresco.web.bean.generator.BaseComponentGenerator;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

where do i find these ?

Thanks
Alex–70

Re: Custom Constraint

acis — Mon, 18 Aug 2008 08:11:01 GMT

Download Alfresco SDK to get the libs.

Re: Custom Constraint

alex--70 — Mon, 18 Aug 2008 14:16:53 GMT

Thank acis.
The example run correctly, but this list is static, in order to apply changes from database, i have to restart alfresco.
I have try to modify the getAllowedValues metod, as you told, but nothing.

Have you other ideas ?

Thansk lot
alex–70

Re: Custom Constraint

acis — Wed, 20 Aug 2008 09:51:55 GMT

I didn't check the suggestion I gave so I don't know if it's working.

but it's strange that the list is not refreshing if you are calling back the loadDb function because the allowedValues list is changed in taht function

maybe you can check if the web interface don't have the list in cache and try to refresh it

Re: Custom Constraint

alex--70 — Wed, 20 Aug 2008 13:18:05 GMT

I have refresh the page but the result is that the list remain with same values (static value)
I used the followed code :

public List getAllowedValues() {
this.loadDB();
super.getAllowedValues();
}

Can you try your code ?

Thank a lot

Re: Custom Constraint

alex--70 — Wed, 20 Aug 2008 15:52:43 GMT

Questiong for "msvoren" , you had the my same problem.

Have you put the new item into the custom constraint (combo box) after reload the record from database ?

Thanks

alex–70

Re: Custom Constraint

marcostopper — Mon, 10 Nov 2008 16:41:24 GMT

How can I force the refresh from db (this.loadDb()) without user interact???

Where I have to put the loadDb call?

I need to write a property by web service code. I write the value I need but if the database changes I got an error. The writing work well if I click on dropdownlist to force the values list to refresh with database value. How can I force the refresh (constraint values) itself (without clikking on the dropdown list? Where I have to put the call "this.loadDB()"??

Please help me.

Thanks!

package org.contezza.customConstraints;

import java.util.ArrayList;
import java.util.List;
import java.sql.*;
//import org.alfresco.i18n.I18NUtil;
import org.alfresco.repo.dictionary.constraint.ListOfValuesConstraint;
import org.alfresco.web.bean.generator.BaseComponentGenerator;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.Serializable;
import javax.faces.model.SelectItem;

public class ListOfValuesQueryConstraint extends ListOfValuesConstraint implements Serializable {

   private static Log logger = LogFactory.getLog(BaseComponentGenerator.class);

   private static final long serialVersionUID=1;

   private List<String> allowedLabels;

   public void setAllowedValues(List allowedValues) {}
   public void setCaseSensitive(boolean caseSensitive) {}

   public void initialize() {
       super.setCaseSensitive(false);
       this.loadDB();
    }

   public List<String> getAllowedLabels() {
      return this.allowedLabels;
   }

   public void setAllowedLabels(List<String> allowedLabels) {
      this.allowedLabels=allowedLabels;
   }

    public List<SelectItem> getSelectItemList() {
      List<SelectItem> result = new ArrayList<SelectItem>(this.getAllowedValues().size());
      for(int i=0;i<this.getAllowedValues().size();i++) {
         result.add(new SelectItem((Object)this.getAllowedValues().get(i),this.allowedLabels.get(i)));
      }
      return result;
   }

    protected void loadDB() {

       String driverName = "org.gjt.mm.mysql.Driver";
        String serverName = "localhost";
        String mydatabase = "alfresco";
        String username = "alfresco";
        String password = "alfresco";

        List<String> av = new ArrayList<String>();
        List<String> al=new ArrayList<String>();

        try {
           Connection connection = null;
            Class.forName(driverName);
            String url = "jdbc:mysql://" + serverName + "/" + mydatabase;
            connection = DriverManager.getConnection(url, username, password);
            Statement stmt = connection.createStatement();
            ResultSet rs = stmt.executeQuery("select code,label from codelabel");
            while (rs.next()) {
                av.add(rs.getString("code"));
                al.add(rs.getString("label"));
            }
        }
        catch (Exception e) {}

      super.setAllowedValues(av);
      this.setAllowedLabels(al);
   }
}

How can I force the refresh from db (this.loadDb()) without user interact???

Where I have to put the loadDb call?

I need to write a property by web service code. I write the value I need but if the database changes I got an error. The writing work well if I click on dropdownlist to force the values list to refresh with database value. How can I force the refresh (constraint values) itself (without clikking on the dropdown list? Where I have to put the call "this.loadDB()"??

Please help me.

Thanks!

Re: Custom Constraint

buddycasino — Tue, 09 Dec 2008 14:45:52 GMT

we could have use the "converter=" attribute in the web-client-config-custom.xml but good luck to do it. I tried hard and it didn't work out.

Thats because you have to declare your converter in the faces-config-custom.xml. Of course, that is not undocumented but simply implied to be a known fact.
But unfortunately that won't help you either, since the converter is used for the value, not the label.
In the edit view, that is, not in the properties view, where it looks correct. Holy jesus on a bicycle….

Re: Custom Constraint

jarrett — Wed, 22 Apr 2009 15:52:59 GMT

Hello,

Once I figured out the imports I was able to get this code to work, I think… I have one remaining issue to resolve and I wasn't sure if anyone else has faced this issue:

In catalina.out the warning is:
WARN [bean.generator.BaseComponentGenerator] ListOfValuesQueryConverter could not be applied

In web-client-config-custom.xml the property is:
<show-property name="ygrd:Geography" component-generator="ListOfValuesQueryGenerator" converter="ListOfValuesQueryConverter"/>

In faces-config-custom my beans are:
<managed-bean>
        <description>Dropdown with lable and value</description>
        <managed-bean-name>ListOfValuesQueryGenerator</managed-bean-name>
        <managed-bean-class>org.contezza.customConstraints.ListOfValuesQueryGenerator</managed-bean-class>
        <managed-bean-scope>request</managed-bean-scope>
</managed-bean>

<managed-bean>
        <description>Dropdown with lable and value</description>
        <managed-bean-name>ListOfValuesQueryConverter</managed-bean-name>
        <managed-bean-class>org.contezza.customConstraints.ListOfValuesQueryConverter</managed-bean-class>
        <managed-bean-scope>request</managed-bean-scope>
</managed-bean>

Any ideas?

Re: Custom Constraint

nikes — Fri, 28 Aug 2009 07:21:11 GMT

nice thread….

I am able to populate drop down from database table and also when I add new value in database it gets reflected in Alfresco.

Re: Custom Constraint

norgan — Wed, 30 Sep 2009 22:56:04 GMT

Hi Nikes,
can you summarize your solution for us as example in the wiki and post a link here ? Idealy, you can put your lessonslearned in there as well ?

That would be great,
Norgan

Re: Custom Constraint

nikes — Thu, 08 Oct 2009 13:27:12 GMT

Please refer below refined code. Its working properly on my implementation.



package org.customConstraints;

import java.util.ArrayList;
import java.util.List;
import java.sql.*;

import org.alfresco.repo.dictionary.constraint.ListOfValuesConstraint;
import org.alfresco.web.bean.generator.BaseComponentGenerator;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.Serializable;
import javax.faces.model.SelectItem;

public class ListOfValuesQueryConstraint extends ListOfValuesConstraint implements Serializable {

   private static Log logger = LogFactory.getLog(BaseComponentGenerator.class);

   private static final long serialVersionUID=1;

   private List<String> allowedLabels;

   public void setAllowedValues(List allowedValues) {}
   public void setCaseSensitive(boolean caseSensitive) {}

   public void initialize() {
       super.setCaseSensitive(false);
       this.loadDB();
    }

   public List getAllowedValues() {
      this.loadDB();
      return super.getAllowedValues(); // In earlier post there is no return statement..
     //return this.getAllowedValues();
}

   public List<String> getAllowedLabels() {
      return this.allowedLabels;
   }

   public void setAllowedLabels(List<String> allowedLabels) {
      this.allowedLabels=allowedLabels;
   }

    public List<SelectItem> getSelectItemList() {
      List<SelectItem> result = new ArrayList<SelectItem>(this.getAllowedValues().size());
      for(int i=0;i<this.getAllowedValues().size();i++) {
         result.add(new SelectItem((Object)this.getAllowedValues().get(i),this.allowedLabels.get(i)));
      }
      return result;
   }

    protected void loadDB() {

       String driverName = "org.gjt.mm.mysql.Driver";
        String serverName = "localhost";
        String mydatabase = "alfresco";
        String username = "root";
        String password = "admin1";

        List<String> av = new ArrayList<String>();
        List<String> al=new ArrayList<String>();


        try {
           Connection connection = null;
            Class.forName(driverName);
            String url = "jdbc:mysql://" + serverName +  "/" + mydatabase;
            connection = DriverManager.getConnection(url, username, password);
            Statement stmt = connection.createStatement();
            ResultSet rs = stmt.executeQuery("select custName from Customers");
            while (rs.next()) {
                av.add(rs.getString("custName"));
                al.add(rs.getString("custName"));
            }
         rs=null;
        }
        catch (Exception e) {}

      super.setAllowedValues(av);
      this.setAllowedLabels(al);
   }
}
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