Question

I have an h:inputText element and an h:message for it:

<h:form id="cancelForm">
    <h:inputText id="days" />
    <h:message for="days" />
</h:form>

So when I open the page, JSF renders a “span” element for the error message. This is ok.
When I press submit the application goes to java and validates the fields:

// Some code
if (error) {
    FacesContext.getCurrentInstance().addMessage("days", new FacesMessage("Error message"));
    return error();
}

But after this JSF does not render the “span” for h:message.

Why?

Answer 1

days is just the simple ID for the inputText component. For the addMessage call you need the full ID (the client ID).

You can obtain the client ID by looking at the rendered HTML source code, or if all parent naming containers on your Facelet have IDs, guess it. It’s typically all the parent IDs concatenated with : as a separator.

To always get the 100% correct ID, bind the inputComponent to your backing bean and in the code fragment you show above query it for its ID.

Finally, one word of advice: typically the kind of error checking and adding faces messages is done via a Validator and/or Converter. Doing this in a backing bean should not be your first approach.