Leveraging PrimeFaces and the p:ajax component, trigger Ajax within an inputText field only when keystrokes lead to changes in the field

Question

Leveraging PrimeFaces and the p:ajax component, trigger Ajax within an inputText field only when keystrokes lead to changes in the field

I am currently utilizing PrimeFaces and have a p:inputText field that requires updating certain components on the view based on the most recent keystroke within that p:inputText. Below is the code snippet:

<p:inputText value="#{customerLController.surnameFilterConstraint}"
             id="surnamefilterfield">
    <p:ajax event="keyup" 
            update=":custForm:custDataTable"
            listener="#{customerLController.focusSurname}"
            oncomplete="primeFacesId('surnamefilterfield')"/>
</p:inputText>

The issue here is that the code triggers Ajax even with arrow key strokes (which I want to avoid due to the expensive update). Ideally, I would prefer an alternative version of p:ajax event="change" with a condition to trigger change events on keystrokes rather than when the user presses Enter key (the current behavior).

If the p:ajax component does not provide a way to filter out specific keyup events, then it seems like the only (?) solution would be to execute JavaScript on the client side and handle the Ajax call in JavaScript. However, this would mean sacrificing the convenience of using the PrimeFaces p:ajax component, right?

javascript ajax primefaces

Answer 1

Answer №1

Ever since the introduction of JSF 2.2, I have found a more elegant solution to this problem.

The solution involves utilizing both p:remoteCommand (as mentioned in a comment) and the use of namespace

http://xmlns.jcp.org/jsf/passthrough

, which enables you to incorporate native HTML event attributes into JSF components.

To implement this solution:

Begin by adding a new namespace to your page

xmlns:pt="http://xmlns.jcp.org/jsf/passthrough"

Next, modify p:inputText and include p:remoteCommand

<p:inputText id="surnamefilterfield" 
          value="#{customerLController.surnameFilterConstraint}" 
          pt:onkeyup="onKeyUpFilterKeyCode(event)" />
<p:remoteCommand delay="300" name="onFilteredKeyUp" 
              actionListener="#{customerLController.focusSurname}" />

Add the JavaScript function

function onKeyUpFilterKeyCode(event){
        var keyCode=event.keyCode;
        console.log("Key code = " + keyCode);
        //if key is not ENTER and not cursor/arrow keys
        if ((keyCode != 13) && !((keyCode >= 37) && keyCode <= 40)){
            //call remoteCommand
            onFilteredKeyUp();
        }
    }

(since this JS function contains "special" XML chars follow BalusC recommendations about how to add it to JSF/XML web page)

This approach offers the advantage of being able to ajaxify any native HTML event supported by the component (and web browser), all while still using JSF/Primefaces components in building web pages in the traditional "JSF way".

Answer 2

Ever since the introduction of JSF 2.2, I have found a more elegant solution to this problem.

The solution involves utilizing both p:remoteCommand (as mentioned in a comment) and the use of namespace

http://xmlns.jcp.org/jsf/passthrough

, which enables you to incorporate native HTML event attributes into JSF components.

To implement this solution:

Begin by adding a new namespace to your page

xmlns:pt="http://xmlns.jcp.org/jsf/passthrough"

Next, modify p:inputText and include p:remoteCommand

<p:inputText id="surnamefilterfield" 
          value="#{customerLController.surnameFilterConstraint}" 
          pt:onkeyup="onKeyUpFilterKeyCode(event)" />
<p:remoteCommand delay="300" name="onFilteredKeyUp" 
              actionListener="#{customerLController.focusSurname}" />

Add the JavaScript function

function onKeyUpFilterKeyCode(event){
        var keyCode=event.keyCode;
        console.log("Key code = " + keyCode);
        //if key is not ENTER and not cursor/arrow keys
        if ((keyCode != 13) && !((keyCode >= 37) && keyCode <= 40)){
            //call remoteCommand
            onFilteredKeyUp();
        }
    }

(since this JS function contains "special" XML chars follow BalusC recommendations about how to add it to JSF/XML web page)

This approach offers the advantage of being able to ajaxify any native HTML event supported by the component (and web browser), all while still using JSF/Primefaces components in building web pages in the traditional "JSF way".

Leveraging PrimeFaces and the p:ajax component, trigger Ajax within an inputText field only when keystrokes lead to changes in the field

Answer №1

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