We have a collection of objects(entities) which has their own validation pattern, so we have to develop a custom JSF validator for them.

The problem is, when we trying to set the validator's property with a EL expression, this expression can not be resolvered exactly, and not getting the correct value in the custom validator.

I doubt it's because the ELContext can't find the Seam context, so that the seam component can not be resolvered.

Here's my code:

MyEntity.java

@Entity
public class MyEntity implements Serializable {
    // other fields
    private String valuePattern;
        private String value;
        // getters and setters
}

RegexValidator.java

@Name("company.regexValidator")
@BypassInterceptors
@Validator
public class RegexValidator implements javax.faces.validator.Validator, Serializable {
        @Logger Log log;
        private String expression;
        private String errorMessage;
        
        public void validate(FacesContext context, UIComponent component, Object value)
                        throws ValidatorException {
                log.info(">>>> validating regex [#0]", expression);
                // compile the regex expression and matches the value
        }
        // setters for the "expression" and "errorMessage"
}

company.taglib.xml

<?xml version="1.0"?>
<!DOCTYPE facelet-taglib PUBLIC
  "-//Sun Microsystems, Inc.//DTD Facelet Taglib 1.0//EN"
  "http://java.sun.com/dtd/facelet-taglib_1_0.dtd">
<facelet-taglib>
    <namespace>http://www.company.com/taglib</namespace>
    <tag>
        <tag-name>validateRegex</tag-name>
        <validator>
            <validator-id>company.regexValidator</validator-id>
        </validator>
    </tag>
</facelet-taglib>

MyBean.java

@Name("myBean")
@Scope(PAGE)
public class MyBean {
        // other business logic
        public List<MyEntity> getMyEntities() {
                // generate the entities
        }
}

myBeanEdit.xhtml

...
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:my="http://www.company.com/taglib"
...
<ui:repeat value="#{myBean.myEntities}" var="myEntity">
        <h:inputText value="#{myEntity.value}">
                <my:validateRegex expression="#{myEntity.valuePattern}">
        </h:inputText>
</ui:repeat>

web.xml

...
        <context-param>
        <param-name>facelets.LIBRARIES</param-name>
        <param-value>/WEB-INF/company.taglib.xml</param-value>
    </context-param>
...

The log from the validator is >>>> validating regex [], I guess it's because the expression EL can not be resolvered correctly,
and I change the code to be:

...
<my:validateRegex expression="[a-zA-Z]*"/>
...

it works fine.

then I try:

@Name("myBean")
@Scope(PAGE)
public class MyBean {
        // other business logic
        public String getRegex() {
                return "[0-9]*";
        }
}

<my:validateRegex expression="#{myBean.regex}">

works fine too....

Then I try to change the faces-config.xml:

...
    <application>
        <el-resolver>org.jboss.seam.el.SeamELResolver</el-resolver>
    </application>
...

Just doesn't work... the expression still can not be resolvered...

My project was generated by seam-gen, Seam 2.0.2SP1, JBoss 4.2.2GA.

how can I resolver this valuePattern exactly in the validator? or may be I should write a tag class? like:

public class RegexValidatorTag extends ValidatorELTag {
        private ValueExpression expression;
        
        public Validator createValidator() throws JspException {
                ELContext elContext = FacesContext.getCurrentInstance().getELContext();
                // how to use SeamELResolver to resolver the expression here?
                RegexValidator validator = new RegexValidator();
                validator.setExpression((String)expression.getValue(elContext));
        }
}

Any comments will be greatful,

Regards.