Update grid using NotifyChange

asked 2019-04-12 07:58:48 +0800

FrankV427 gravatar image FrankV427
5 2

In my code, I have a textbox in which you can insert text and a button to 'publish' that text. Beneath there is a grid, in which all the previously published posts appear. The issue is that, using the @NotifyChange doesn't work, or I dont know how it works well enough to make it update the grid. Here is the .zul:

    <borderlayout id="main" apply="org.zkoss.bind.BindComposer" viewModel="@id('vm') @init('pojos.PostController')">

    <!--Skipping code-->

    <center style="padding:15px;" border="none">


            <window title="Crear Publicacion " border="normal">

                <textbox id="publish" placeholder="Make a post" 
                         height="40px" width="67%" multiline="true">
                    <attribute name="onChanging">
                        String value = event.value;     
                        publSize.setValue("" + value.length() + "/300");
                <space width="1%"/>
                <textbox id="publSize" height="40px" width="6%" style="text-align:center" disabled="true" placeholder="0/300"/>    
                <space width="1%"/>
                <button id="publicaBttn" label="Publicar" height="40px" width="25%" onClick="@command('addNewPost', p=publish)"/>


            <separator bar="false"/>

            <grid id="postGrid" height="550px" model="@init(vm.posts)" emptyMessage="Nothing in Posts.">

                <template name="model">


                        <window border="normal">

                            <caption id="userName" label="@load(each.username)"/> 
                            <textbox id="infoPost" readonly="true" value="@load(each.info)" multiline="true" rows="4" width="100%" mold="rounded"/>
                            <separator bar="true"/> 
                                    <button label="Like" onClick="@command('addLike', index=each.index)"/>
                                <div hflex="true">
                                    <textbox id="likeTB" disabled="true" width="3%" style="text-align:center" value="@load(each.likes)"/>
                                <div style="padding-right">



Here is the java controller:

public void addPost(@BindingParam("p") Textbox tbx) {
    String text = tbx.getValue();
    if (text == "") {
        Messagebox.show("¡No se puede crear una publicacion sin texto!", null, 0, Messagebox.ERROR);
    if (text.length() > 300) {
        Messagebox.show("¡La publicaciones deben de ser menores a los 300 caracteres!", null, 0, Messagebox.ERROR);
    } else {

public void addLike(@BindingParam("index") String index) {

When I either add a like or make i new post, the grid doesnt update to show the new like or the new post added. How can i solve this?

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1 Answer

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answered 2019-04-17 10:33:52 +0800

hawk gravatar image hawk
2320 1 5
http://hawkphoenix.blogsp... ZK Team

The first problem is you specify model="@init(vm.posts) which tells ZK load vm.posts just once and no reload in the future. So @NotifyChange doesn't take effect. replace it with @load(vm.posts). please refer to http://books.zkoss.org/zk-mvvm-book/8.0/data_binding/initialization.html

Another problem is you specify vm.posts on the Grid, but you notify hConn. I don't see any relationship between these 2 objects. Normally, if you specify vm.posts, you should notify the same property, e.g. @NotifyChange("posts").

If you assign a ListModelList to a Grid's model, when you call any API to modify the ListModelList, it will notify the Grid automatically. No need to add @NotifyChange. So if you call ListModelList.add(newText) then Grid will render the new text.

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Asked: 2019-04-12 07:58:48 +0800

Seen: 6 times

Last updated: Apr 17

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