Unable to maintain JSF ViewState within a dataTable component - jsf

Question

I'm working an inherited JSF app. Still quite new to it.
Here's a screenshot of the page I'm working with: http://goo.gl/GidpCD. This is some exam software and what you're looking at is question administration. On this screen the user can write the question, cite the question source, write answers, associate to a category and associate images.
Where I'm getting stuck is when I add/delete answers down toward the bottom.
I'm suspicious that my issue is with ViewState.
When I click the add or delete answers. The page reloads and I lose my file associations within a JSF dataTable component. ViewState is maintained in all of the other form elements on the page, it's just those files within that dataTable that I can't seem to get my head wrapped around. Here's that JSF dataTable component (I'll list the code in it's entirety below):
<h:dataTable id="table0" value="#{adminQuestions.filesList}" var="file" columnClasses="id,title,selected last" rendered="true" >
<h:column>
<f:facet name="header">File</f:facet>
<h:graphicImage value="#{file.path2}" alt="" />
</h:column>
<h:column>
<f:facet name="header">Title</f:facet>
<h:outputText value="#{file.title}" />
</h:column>
<h:column>
<f:facet name="header">Select files</f:facet>
<h:selectBooleanCheckbox value="#{file.selected}" />
</h:column>
</h:dataTable>
Here's the JSF button compnent to fire the add add answer method:
<h:commandButton value="#{msgs.addButton}" action="#{adminQuestions.addQuestionToAnswerRow}" />
And here's that add answer method:
public String addQuestionToAnswerRow() {
if(this.questionToAnswerList.size() < 8) {
// set the scroll
if(FacesContext.getCurrentInstance().getMessageList().size() > 0) {
this.scroll = false;
}
else {
this.scroll = true;
}
//Create a new answer, set the current question, and add it to the collection
Answers answer_local = new Answers();
QuestionToAnswer qta_local = new QuestionToAnswer();
answer_local.setTitle(this.inputTextAnswer);
answer_local.setDescription(this.inputTextAnswer);
answer_local.setCorrect(this.correctAnswer);
qta_local.setAnswers(answer_local);
qta_local.setAnswer(this.questionToAnswerList.size() + 1);
qta_local.setQuestions(this.question);
this.questionToAnswerList.add(qta_local);
// reset the input fields
this.inputTextAnswer = "";
this.correctAnswer = false;
List<File1> thisFilesList = getFilesList();
QuestionsToFiles qtf;
List<QuestionsToFiles> qtfc = new ArrayList<QuestionsToFiles>();
if(this.filesList != null) {
for(Iterator<File1> entries = this.filesList.iterator(); entries.hasNext();) {
File1 file_temp = entries.next();
if(file_temp.isSelected()) {
qtf = new QuestionsToFiles();
qtf.setQuestions(this.question);
qtf.setFile1(file_temp);
qtfc.add(qtf);
}
}
}
return null;
}
else {
JSFUtils.addErrorMessage("No more than eight answers are allowed: ", "The question cannot have more than eight answers");
return null;
}
}
Here's the JSF button component to fire the delete method
<h:commandButton value="#{msgs.deleteButton}" action="#{adminQuestions.deleteQuestionToAnswerRow(a)}" />
And the delete method:
public String deleteQuestionToAnswerRow(QuestionToAnswer qta_local) {
// set the scroll
if(FacesContext.getCurrentInstance().getMessageList().size() > 0) {
this.scroll = false;
}
else {
this.scroll = true;
}
//Iterate through the category exam collection and delete the associated category so it's reflected on the page
for (Iterator<QuestionToAnswer> itr = this.questionToAnswerList.iterator(); itr.hasNext();) {
QuestionToAnswer qta_temp = itr.next();
if(qta_temp == qta_local) {
qta_temp.setQuestions(null);
qta_temp.setAnswers(null);
itr.remove();
return null;
}
}
return null;
}
Here's a Gist the XHTML page in it's entirety
Here's a Gist the Java class in it's entirety
Thanks for taking a look.