Skip to main content

4 Remarkable Notes for JSF Apps Using HTML5


In the previous post, I've already shared with you how my team consults clients by using a HTML prototype. This post is about the used technologies for reusing the provided HTML template and communicating with backend.

What is the issue when using HTML elements with Primefaces components?

Primefaces is a great extension for developing JSF web apps. However, it is really frustrating in case we have to make it work with an existing HTML template. Why?
- Primefaces has its own theme for styling.
- Primefaces changes the HTML structure.
Therefore, that would be a huge effort to use the Primefaces' components to replicate the elements of the HTML template; especially it is impossible for images drawing by "canvas" tag.

That requires us to find a better approach. Since Java EE 7 (introducing JSF 2.2 included), it supports to use HTML5 elements. The idea is that JSF components don't effect the style and HTML structure, so we can easily reuse the provided HTML template. Moreover, we're still able to use Primefaces "No-GUI" components such as "p:ajax", "p:remoteCommand'.

1. JSF Alternatives for HTML5 elements

We can choose to use JSF components, HTML5 elements, or both. Take a look the table "How Facelets Renders HTML5 Elements" of the following link for more detail.
https://docs.oracle.com/javaee/7/tutorial/jsf-facelets009.htm
For example:
<html ... xmlns:jsf="http://xmlns.jcp.org/jsf"
...
    <input type="email" jsf:id="email" name="email"
           value="#{reservationBean.email}" required="required"/>

2. Radio button or How to make a trick for events

There is no JSF component for radio elements. We have to build an alternative by our own. For example:
<div id="gender">
 <div class="control">
  <input type="radio" name="option" checked="true"
   onclick="document.getElementById('gender-hidden-input').setAttribute('value', '0'); onGenderChange();" value="0"></input>
  <label class="control__label" for="optionone">Option One</label>
 </div>
  
 <div class="control">
  <input type="radio" name="option" 
    onclick="document.getElementById('gender-hidden-input').setAttribute('value', '1'); onGenderChange();" value="1"></input>
  <label class="control__label" for="optiontwo">Option Two</label>
 </div>
  
 <h:inputText value="#{data.dataModel.gender}" styleClass="hidden" type="text" id="gender-hidden-input" />
 <p:remoteCommand name="onGenderChange" actionListener="#{logic.onGenderChange}" update="growl"></p:remoteCommand>
</div>

3. Dialog or How to custom Ajax requests

For dialogs/pop-ups, we can use a JQuery library like basicLightbox. We can use "p:remoteCommand" to call ajax  requests to backend. The following is an idea for passing a javascript function as param when executing from different places.
...
okElem.forEach(function (elem) {
 elem.onclick = function (e) {
  
  if(elem.classList.contains("mf-ui-disabled")){
   return false;
  }
  
  var ajaxRequestor = elem.getAttribute('data-ajax-requestor');
  if(ajaxRequestor){
   executeFunction(ajaxRequestor); //ajaxRequestor is a javascript function name which can make by "p:remoteCommand"
  }
  
  instance.close();
  e.preventDefault();
 };
});

...

function executeFunction(functionStr){
 var fn = window[functionStr];
 if (typeof fn === "function") fn();
}

4. Images Exporting

So far, html2Canvas has been the only one library can help us satisfy the requirements of exporting images from client side for all supported browsers including Chrome, Firefox and IE11. Almost other libraries for "html and canvas conversion" won't work with IE due to IE does not support SVG <foreignObject> tag. A fun fact here is this library even has not been released at the time we applied it for our project.
function exportProductChart(){
 
 var productHouse = document.querySelector("#overallPdfExportHouseWrapper");
 
 html2canvas(productHouse, {
   scale: 3,
      onrendered: function(canvas) {
       var productHouseImg = canvas.toDataURL("image/png");
       onClickExportPdfDialogOkBtn = function() {//override the function "onClickExportPdfDialogOkBtn" because this function can be called in another place.
     PrimeFaces.ab({
      s:"onClickExportPdfDialogOkBtn",
      f:"mainForm",
      p:"pdfExportDialog",
      u: "pdfExportDialog",
      onco:function(xhr,status,args){
       $('[id$=downloadPdf]').click();
      },
      pa:[{name: "mfDialogAction", value: "productChartExport"},
          {name: "productChoiceHouse", value: productHouseImg}]
     });
    }
    onClickExportPdfDialogOkBtn(); //p:remote command
    }
 });
}

References:
[1]. http://www.oracle.com/technetwork/articles/java/enterprise-html5-2227136.html
[2]. https://docs.oracle.com/javaee/7/tutorial/jsf-facelets009.htm
[3]. https://github.com/tsayen/dom-to-image
Labels:

Comments

  1. Hiếu LêJanuary 30, 2018 at 6:45 AM

    Chào anh Hương, em là sinh viên mới tiếp cận Java và CNTT nên không biết nhiều. Em đang định dùng lại code mã nguồn mở của SweetHome 3D nhưng mò mẫm mãi vẫn không xem được code của họ. Mong anh chỉ giáo

    ReplyDelete
    Replies
    1. Huong NguyenJanuary 30, 2018 at 9:52 PM

      Chào bạn!
      Tôi chưa có kinh nghiệm lập trình với SweeHome 3D, nên tôi sẽ chỉ có thể cho lời khuyên:
      1. Bạn nên làm theo hướng dẫn này Developer Guide. (phải cái bạn nỏi không??)
      2. Bạn xem source code của file jar (Download) bằng java decompiler (vd: JD) hoặc cài plugin decompiler trên Eclipse.

      Không biết bạn đã tham gia cộng đồng này Dạy Nhau Học chưa, nếu chưa thì bạn có thể lên đây đặt câu hỏi và chia sẻ lại với mọi người.

      Delete

Post a Comment

Popular posts from this blog

Junit - Test fails on French or German string assertion

In my previous post about building a regex to check a text without special characters but allow German and French . I met a problem that the unit test works fine on my machine using Eclipse, but it was fail when running on Jenkins' build job. Here is my test: @Test public void shouldAllowFrenchAndGermanCharacters(){ String source = "ÄäÖöÜüß áÁàÀâÂéÉèÈêÊîÎçÇ"; assertFalse(SpecialCharactersUtils.isExistSpecialCharater(source)); } Production code: public static boolean isExistNotAllowedCharacters(String source){ Pattern regex = Pattern.compile("^[a-zA-Z_0-9_ÄäÖöÜüß áÁàÀâÂéÉèÈêÊîÎçÇ]*$"); Matcher matcher = regex.matcher(source); return !matcher.matches(); } The result likes the following: Failed tests: SpecialCharactersUtilsTest.shouldAllowFrenchAndGermanCharacters:32 null A guy from stackoverflow.com says: "This is probably due to the default encoding used for your Java source files. The ö in the string literal in the J...
5 comments
Read more

How I did customize "rasa-nlu-trainer" as my own tool

Check out my implementation here Background I wanted to have a tool for human beings to classify intents and extract entities of texts which were obtained from a raw dataset such as Rocket.chat's conversation, Maluuba Frames or  here . Then, the output (labeled texts) could be consumed by an NLU tool such as Rasa NLU. rasa-nlu-trainer was a potential one which I didn't need to build an app from scratch. However, I needed to add more of my own features to fulfill my needs. They were: 1. Loading/displaying raw texts stored by a database such as MongoDB 2. Manually labeling intents and entities for the loaded texts 3. Persisting labeled texts into the database I firstly did look up what rasa-nlu-trainer 's technologies were used in order to see how to implement my mentioned features. At first glance rasa-nlu-trainer was bootstrapped with Create React App. Create React App is a tool to create a React app with no build configuration, as it said. This too...
Post a Comment
Read more

My must-have apps for daily work

There is no doubt that cool apps can help us be more productive and enjoyable at work. For the time being, I really love the following apps which are used by me almost every day. 1. A personal Kanban In fact, a personal kanban is the most useful app for me. Why does it matter? It is not just a to-do list, but it keeps me motivated every day because it helps me be able to know what my "big picture" is. I usually set up my plans together with a path to reach them.  KanbanFlow  is my preferred tool. KanbanFlow 2. A terminal Needless to say, a terminal is a must-have app for every developer, especially the ones use macOS/Linux. Due to its importance, I love to decorate and enhance it to be super exciting with various tools such as  iTerm ,  oh-my- zsh , and  thefuck . ;) iTerm + oh-my-zsh 3. A documentation "ecosystem" As a developer, I can not remember all things that I have experimented a day. Moreover, a document is really useful for sharing an...
Post a Comment
Read more

The power of acceptance test

User Story is the place PO gives his ideas about features so that developers are able to know what requirements are. Acceptance tests are these show the most valuable things of the features represented by some specific cases. Usually PO defines them, but not always. Therefore, refining existing acceptance tests – even defining new ones that cover all features of the User Story must be a worth task. Acceptance test with Given When Then pattern If we understand what we are going to do, we can complete it by 50% I have worked with some members those just start implementing the features one by one and from top to down of the User Story description. Be honest, I am the one used to be. What a risky approach! Because it might meet a case that is very easy to miss requirements or needs to re-work after finding any misunderstood things. I have also worked with some members those accept spending a long time to clarify the User Story. Reading carefully of whole User Story by defining...
Post a Comment
Read more

Fulfilling Your Contribution Needs

Human resource management motivation Managing human today is quite different from the industrial age which treats people as just "chickens". Rather than people now are very important to the success of an organization. People are an organization's special resource. They should be encouraged to grow to contribute their effort and creativeness to their beloved working environment because the contribution is one of their most needs in life. Training people: getting rid of the ineffective model and adopting the new one The ineffective model of training people: Hiring new people --> giving them a crash course once --> expecting them working effectively.  That somehow makes sense but you're about to expect a luck because you do not really spend your effort for mentoring them. If they can work effectively, well...lucky you! Otherwise, you will blame that these people are ineffective and you let them go and hire the new ones. What a waste of time! The new effe...
Post a Comment
Read more