Tag Archives: ajax

jQuery Dialog – how to submit a form with ajax

Today I searched for a solution to submit a form embedded into a jQuery dialog with ajax.

My situation is the following: I use a jQuery UI Dialog to display a feedback-form in my web application. The feedback form should not change the state of the page the user worked before.

So my first approach was to change my form post action into a ajax post action. This can be done easily during the initialisation of the dialog. See the following code snippet:

/**
 * Method to initialize the feedback dalog.
 * @see contact_dialog.xhtml
 */
function initContactDialog() {
    // set default settings for profile dialog
    $("#dialog-contact").dialog({
        resizable : false,
        height : 530,
        width : 550,
        modal : true,
        autoOpen : false
    });

    // hide contact dialog per default
    $("#dialog-contact").hide();

    // the following method modifies the submit request into a ajax request
    // So the dialog will be closed after the submit was successfull without
    // affects to the main page.
    $('#dialog-contact-form').submit(function() {

        // show up waiting panel
        $(".ajax-wait-panel").addClass("ajax-waiting"); 

        $.ajax({
               type: "POST",
               url: "http://localhost:8080/myrestservice",
               data: $("#dialog-contact-form").serialize(), // serializes the form's elements.
               success: function(data)
               {
                   $(".ajax-wait-panel").removeClass("ajax-waiting"); 
                   $("#dialog-contact").dialog("close");
               },
               error: function(data)
               {
                   alert('An error occured. Could not send data!'); // show response from post.
                   $(".ajax-wait-panel").removeClass("ajax-waiting"); 
               }
             });

        return false; // avoid to execute the actual submit of the form.
    });

}

With the initContactDialog() method I initialize the dialog and bind a function to the submit event of my form. The function changes the submit into a ajax call and closes the dialog after the ajax request was finished.

This is quite easy and the dialog will automatically close when the Ajax submit was finished.

Here is the html part of my dialog form:

    <!-- Dialog Box -->
        <div id="dialog-contact"  title="#{global.contact_title}">
            <form id="dialog-contact-form" method="post" name="contact_form">

                <h:panelGrid columns="2">

                    <h:panelGroup>
                        <dl>
                            <dt>#{global.contact_firstname}:</dt>
                            <dd>
                                <input type="text" name="txtfirstname" value="" />
                            </dd>
                        </dl>
                    </h:panelGroup>
                    <h:panelGroup>
                        <dl style="">
                            <dt>#{global.contact_lastname}:</dt>
                            <dd>
                                <input type="text" name="txtlastname" value="" />
                            </dd>
                        </dl>
                    </h:panelGroup>
                    <h:panelGroup>
                        <dl style="">
                            <dt>#{global.contact_email}:</dt>
                            <dd>
                                <input type="text" name="txtemail" value="" />
                            </dd>
                        </dl>
                    </h:panelGroup>
                </h:panelGrid>
                <dl style="margin: 0 0 0 0px;">
                    <dt>#{global.contact_message}:</dt>
                    <dd>
                        <textarea style="width: 450px; height: 80px;" name="_description" />
                    </dd>
                </dl>
                <input type="submit" value="send" />

            </form>
            <div>
                <h2>#{global.please_wait}</h2>
            </div>
        </div>

I open the dialog with the following JavaScript function:

 /**
 * helper method to open the contact dialog. 
 * The method creates a new empty contact workitem.
 */
function openContact() {    
   $("#dialog-contact").show();
   $("#dialog-contact").dialog("open");
}

AJAX ‘WAIT-PANEL’

As you can see in my script and in the html snippet I have added a div section with the class ‘ajax-wait-panel’. This div overlays the form of my dialog when the ajax call is started. So the user will see a ‘Please wait’ message until the ajax request is finished. I simply add the class ‘ajax-waiting’ to the div section in the moment the request starts and remove the class when the submit was finished. So this is the css part of my solution:

/* Ajax-wait-panel can be useded in jquery dialogs
   for long runnign ajax request.
   Start by setting display:none to make this hidden.
   Background we set to 80% white with
   our animation centered, and no-repeating */
 .ajax-wait-panel {
    display:    none;
    position:   absolute;
    z-index:    1000;
    top:        0;
    left:       0;
    height:     100%;
    width:      100%;
    background: rgba( 255, 255, 255, .6 ) 
                url('ajax-loader.gif') 
                50% 50% 
                no-repeat;
    cursor: wait;
}

.ajax-wait-panel  h2 {
    position: absolute;
    top: 50%;
    margin-top: -80px;
    color: #666;
    text-align: center;
    width: 100%;
}
/* Class to be added when ajax wait panel should 
   be displayed */
.ajax-waiting {
     display: block;
}

JSF f:ajax – How to locate componets outside the current context

Using JSF 2.0 and Ajax simplifies the web design and provides a lot of cool tricks to extend the user experience. With the render and execute tags form the f:ajax tag it is use to update components dynamically.

But in the past I run often into problems when trying to update a component outside the current ui context. For example when you try to update a part of your form for a single row in h:datatable component you will typically see log messages like this one:

f:ajax contains an unknown id 'j_idt90:painelTabela' - cannot locate it in the context of the component j_idt75

To solve such kind of problems you need to specify the full component id to be rendered or executed. This is not always as easy at it sounds. When your component is nested in a complex component tree the component id can be prafixed with a long list of parent component ids. This happens typically in h:datatables, ui:repeats or c:forEach sections.

One solution is to navigate back in the tree to the correct ui node and get the componentID using an EL syntax like this:

<f:ajax render=":#{component.parent.parent.parent.parent.clientId}:new-minute-panel:" />

This looks not really nice and it creates new problems when you redesign or move your ui components into a new structure on your jsf page.

A simple trick to solve the problem is to bind the component which need to be rendered into a ui param. So you can reference its full clientId in the ajax context. See the following example:

<h:panelGroup layout="block" id="mylist" binding="#{myListComponent}">                
   <ui:repeat var="attachment" value="#{myController.myList}">
       ....
       <!-- some ajax functionality... -->
       <f:ajax render=":#{myListComponent.clientId}">
           <h:commandLink actionListener="#{myController.soSomething}">click me</h:commandLink>
       </f:ajax>
 ...
   </ui:repeat>
....

In this example I use the binding tag to bind the panelGroup to a param named ‘myListComponent’. Inside the ui:repeat I can now access the outer component and render the component fom my f:ajax element accessing the clientId

<f:ajax render=":#{myListComponent.clientId}"

As a result the ajax component no longer depends on the position in my page and I can reuse it in any part of my jsf page.

TRANSFER CLIENTIDS TO SUBFORMS

Another solution using the binding is to transfer a component into a subform. See the following example:

 <h:panelGroup id="my_panel" binding="#{myListComponent}">
     <h:dataTable id="mydatatable" value="#{myController.myList}" var="child">
       .....
        <ui:include src="/forms/sub_myeditor.xhtml" >
            <ui:param name="myPanel" value="#{myListComponent}" />            
        </ui:include>
       .....
     </h:dataTable>

In this example I transfer the ui:component containing my h:datatable to a subpage ‘sub_myeditor.xhtml’  which is included inside the table. Now I can access the panelGroup inside my subpage and render it after an ajax event:

<h:commandButton ....  >
       <f:ajax render=":#{myListComponent.clientId}" 
                execute=":#{myListComponent.clientId}"/>
</h:commandButton>

Also in this example the component in the ajax tag is addressed with its absolute path.

JSF 2.0 – ajax suggestion box

Since JSF 2.0 has introduced the ajax support it is quite simple to implement functional widgets like a suggestion input box. The following short tutorial shows how to build your own suggestion widget using JSF 2.0 and it’s ajax capabilities.

1. THE HTML FORM

First you need a simple input field where the user can type in a search phrase. This can be done wit the h:inputText element. After the user typed in some character a suggestion widget should start a backend search and provide the user with a list of suggestions (you can see this behaviour when searching for something on google.com). To connect your inputText element with a backend component you can use the new build-in ajax feature provided by JSF 2.0. So your input element looks something like this:

<h:panelGroup layout="block" style="margin-bottom:5px;">
     <h:inputText value="#{suggestController.input}">
        <f:ajax event="keyup"  render="suggest_box" /> 
     </h:inputText>
</h:panelGroup>

 

2. DEFINE THE SUGGEST BOX

With the ‘render’ attribute of the f:ajax tag you specify which part of your page should be rerendered after the ajax event was fired. In this case an element with the ID ‘suggest_box’ will be updated. This is the part where you can display the results of your backend search:

<h:panelGroup id="suggest_box">
	<ul>
		<ui:repeat var="entry" value="#{suggestController.result}">
			<li>#{entry}</li>
		</ui:repeat>
	</ul>
</h:panelGroup>

 

To bind you backend component (suggestController) to the event just use the listener tag:

 <f:ajax event="keyup" render="suggest_box"
	listener="#{suggestController.search}" >
</f:ajax>

Your suggest controller implementation can look like this:

....
public void search(AjaxBehaviorEvent event) {
	....
	result=new ArrayList<String>();
	....
}

public List<String> getResult() {
	return result;
}

If you are working with EL 2.2 support (GlassFish 3.1) you can also pass params as method arguments:

<f:ajax event="keyup" render="suggest_box"
	listener="#{suggestController.search('abc')}" >
</f:ajax>
public void search(String param) {
       ..
}

 

3) LAYOUT

Now you can do some layout stuff. Typically the suggestion box should only be displayed with a user typed in a search phrase. And the suggestion box should hidden if the focus is lost. This can be done with some css definition:

.suggestbox {
	position: relative;
}

.suggestbox .resultlist {
	display: block;
	position: absolute;
	z-index: 1;
	left: 2px;
	top: 22px;
	border: 1px solid #CCC;
	background-color: #EEE;
}

To hide the resultlist you can use the f:ajax event ‘blur’

 <f:ajax event="blur" render="suggest_box"
                    listener="#{suggestController.reset}" />

The listener is bound to a backend method which resets the result list. So you can display the complete box in order of the current result. This is the complete code:

JSF Code:

<h:panelGroup layout="block">
	<!-- Process references -->
	<h:panelGroup layout="block" style="margin-bottom:5px;">
		<h:inputText value="#{suggestController.input}">
			<f:ajax event="keyup" render="suggest_box"
				listener="#{suggestController.search('')}" />
			<f:ajax event="blur" render="suggest_box"
				listener="#{suggestController.reset}" />
		</h:inputText>
	</h:panelGroup>
	<h:panelGroup id="suggest_box">
		<h:panelGroup id="suggest_resultlist"
			rendered="#{! empty suggestController.result}">
			<ul>
				<ui:repeat var="entry" value="#{suggestController.result}">
					<li>#{entry}</li>
				</ui:repeat>
			</ul>
		</h:panelGroup>
	</h:panelGroup>
</h:panelGroup>

 SuggestController:

@Named("suggestController")
@RequestScoped
public class SuggestController implements Serializable {

	private static final long serialVersionUID = 1L;
	private List<String> result=null;
	private String query = null;
	private String input =null;
	
	public SuggestController() {
		super();
		result = new ArrayList<String>();
	}

	public String getQuery() {
		return query;
	}

	public void setQuery(String query) {
		this.query = query;
	}

	public String getInput() {
		return input;
	}

	public void setInput(String input) {
		this.input = input;
	}
	
	public void reset(AjaxBehaviorEvent event) {
		 result=new ArrayList<String>();
	}
	
	public void search(String query) {
    	result=new ArrayList<String>();
		result.add("Hallo "  + System.currentTimeMillis());
		result.add("World "+ + System.currentTimeMillis());

	}
	
	public List<String> getResult() {
		return result;
	}

}

4) DELAY AJAX EVENTS

Maybe you run into a problem with the onblur ajax call to hide your overlay section. If the section contains h:command links or buttons the action and actionListeners will not be called because the ajax blur event hides the overlay to early.

With a trick from BalusC you can delay the blur event a little bit. So just add the following jQuery code into your page:

$(document).ready(function() {
	$(".suggestinput").each(function(index, input) {
	    var onblur = input.onblur;
	    input.onblur = null;
	
	    $(input).on("blur", function(event) {
	        delay(function() { onblur.call(input, event); }, 300);
	    });
	    // turn autocomplete of
	    $(this).attr('autocomplete','off');
	});

});

var delay = (function() {
    var timer = 0;

    return function(callback, timeout) {
        clearTimeout(timer);
        timer = setTimeout(callback, timeout);
    };
})();