adding a new row

[waq]

I have a form for courses registeration. Form contains different components like text fields. There is another field called Topics. Now i want to provide the user with an option that he can add more than one topic. So is there any way that i can add a new row with an empty text field?

One way i know is by using javascript but in that case we are not sure how many backing mean property is requried for the Topics field, since user can select as many topics as he wants.

[ilya_shaikovsky]

http://in.relation.to/11633.lace - this case contains not the concrete code for yours case but I think clearly shows the way. In the thread tabs added dynamically on search, and in your case all is even simplier - just to add one more input on clicking some add button.

[waq]

is there any other way instead of using JSTL?

[elf]

In case of "another field called Topics"  is table, may be it will be good to:

1. create ADD button on UI

2. call some bean action clicking this button

3. add new Topic class object to bean array (binded to UI table)

4. refresh table on complete this action

[waq]

ok i did as:

.XHTML

<

a4j:outputPanel id="topics_panel">

<a4j:region id="topic_region">

<h:dataTable value="#{regesterCourse.topicList}" var="top">

<h:column>

<h:inputText id="course_topics"

value="#{top.topic}" size="20" />

</h:column>

</h:dataTable>

<a4j:commandButton value="A" reRender="topics_panel"

action="#{regesterCourse.addNewRow}"/>

</a4j:region>

<a4j:status for="topic_region" startText="Wait" stopText=""/>

</a4j:outputPanel>

.JAVA

public

void addNewRow() {

topicList.add(new TopicList(""));

}

//end addNewRow()

but it adds only one row, even button calls the action everytime i hit it.

[waq]

any suggestions...???

[nbelaevski]

What is bean scope?

[waq]

its request

[nbelaevski]

Use scope with longer lifetime, e.g. session or conversation.

[waq]

can t:saveState work for it? But why it still calls action on every button hit?

[waq]

ok i used a4j:keepAlive and it works for me but when i press submit button it thorws java.lang.IllegalStateException.

After debugging i came to know that exception is comming from the following .JAVA statement:

HttpSession session = (HttpSession)

context.getExternalContext().getSession(false);

[waq]

any solution on this? i found that the issue occur because session got invalidated. but can't able to find the solution for this.

Moreover i am trying to provide a delete functionality to the user which allows the user to delete the current row. It works fine but it always delete the last row.

<

rich:dataTable value="#{regesterCourse.topicList}" var="top"

rowKeyVar="row">

<rich:column>

<h:inputText id="topic_list_fld" value="#{top.topic}"/>

<a4j:commandButton value="Delete" reRender="topic_panel"

action="#{regesterCourse.removeTopicRow}">

<a4j:actionparam value="#{row}"

assignTo="#{regesterCourse.topicIndex}"/>

</a4j:commandButton>

</rich:column>

<rich:column>

<h:outputText value="#{row}"/>

</rich:column>

</rich:dataTable>

public

void removeTopicRow() {

System.

out.println("index is ......." + this.getTopicIndex());  //THIS STATEMENT ALWAYS RETURN 0

topicList.remove(this.getTopicIndex());

}

//end removeTopicRow()

[waq]

any suggestions...???

[waq]

waq wrote:

Moreover i am trying to provide a delete functionality to the user which allows the user to delete the current row. It works fine but it always delete the last row.

I beg your pardon. it always delete the first row.

Please do help me out on this issue. I've been googling since yesterday but not come up with any solution yet.

[nbelaevski]

Have you checked if "#{regesterCourse.topicIndex}" expression has ever been updated?