I have a page, which is used for building queries and running them against different entities (Kind of a query builder/generic search).
The results are displayed in JQGrid, so effectively the same grid will be used for rendering results from different entities.
This results grid has to support context menus, which will differ for each entity. So I need a way to change the context menu as per the entity. Each entity may have different number of menu items in context menu and each item may respond in a different manner (sometimes an alert, sometimes an action spawning in a different tab).
Rendering different menus (through li) is not an issue but attaching the methods to the li is proving to be a challenge. Any pointers will be highly appreciated.
I am using jquery.contextmenu-ui.js .
Following is from a sample that I picked from their (JQGrid) site
function initGrid() {
$("#EntityGrid").contextMenu('cMenu'
,{
bindings: { /* I would like to avoid this and pass all the actions to one method*/
'edit': function (t) {
editRow();
},
'add': function (t) {
addRow();
},
'del': function (t) {
delRow();
}
},
onContextMenu: function (event, menu) {
var rowId = $(event.target).parent("tr").attr("id")
var grid = $("#EntityGrid");
grid.setSelection(rowId);
return true;
}
}
);
}
Thanks,
Avinash
You can use onShowMenu callback of contextMenu instead of static binding using bindings. In the same way the menuId used as the first parameter of contextMenu could be the id of dynamically created div with empty <ul>. The onShowMenu has the form
onShowMenu: function (e, $menu) {
// here one can clear `<ul>` child of $menu
// and append it with "<li>" items
return $menu;
}
In the answer you will find an example of the code which build menu dynamically.
Related
Use Case 1 is answered below, Use Case 2 has been moved to a separate question (Vaadin Flow: Returning to a view, the view should not reload data from the backend)
I'd like to use a Vaadin Flow (v14 LTS/v19) grid component backed by a lazy DataProvider which does not automatically fetch data from the backend when the grid is shown.
There are at least two use cases:
showing grid data does not make sense unless the user provided filter parameters
returning to a #PreserveOnRefresh tagged view should not replace the shown data with current data. (further elaborated in update)
Being pretty new to Vaadin 14+, I could not figure out how to achieve this. Every time my GridView is displayed, the count and fetch callbacks of DataProvider are queried. The call originates from the DataCommunicator of the grid.
So for Use Case 1: How to stop the DataProvider from fetching data as long as it does not make sense?
And for Use Case 2: How to prevent overwriting the grid state when adding a grid to the UI for the second time?
Thanks a lot!
StackTrace to my fetch callback (Vaadin Flow 14):
at org.vaadin.example.GridView.fetch(GridView.java:46)
at org.vaadin.example.GridView.lambda$new$c4b2c115$1(GridView.java:23)
at com.vaadin.flow.data.provider.CallbackDataProvider.fetchFromBackEnd(CallbackDataProvider.java:137)
at com.vaadin.flow.data.provider.AbstractBackEndDataProvider.fetch(AbstractBackEndDataProvider.java:61)
at com.vaadin.flow.data.provider.DataCommunicator.fetchFromProvider(DataCommunicator.java:362)
at com.vaadin.flow.data.provider.DataCommunicator.activate(DataCommunicator.java:647)
at com.vaadin.flow.data.provider.DataCommunicator.collectKeysToFlush(DataCommunicator.java:589)
at com.vaadin.flow.data.provider.DataCommunicator.flush(DataCommunicator.java:461)
at com.vaadin.flow.data.provider.DataCommunicator.lambda$requestFlush$2f364bb9$1(DataCommunicator.java:425)
at com.vaadin.flow.internal.StateTree.lambda$runExecutionsBeforeClientResponse$2(StateTree.java:390)
at [java.util.stream] omitted
at com.vaadin.flow.internal.StateTree.runExecutionsBeforeClientResponse(StateTree.java:387)
at com.vaadin.flow.server.communication.UidlWriter.encodeChanges(UidlWriter.java:411)
at com.vaadin.flow.server.communication.UidlWriter.createUidl(UidlWriter.java:187)
at com.vaadin.flow.server.communication.UidlRequestHandler.writeUidl(UidlRequestHandler.java:122)
at com.vaadin.flow.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:91)
at com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40)
at com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1547)
at com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:247)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
update 20210430
Here's the code of my GridView which also fakes the backend DataProvider:
#Route(value = "grid", layout = MainView.class)
public class GridView extends VerticalLayout {
public GridView() {
final Grid<Person> g = new Grid(Person.class);
g.setColumns("name");
g.setDataProvider(DataProvider.fromCallbacks(q -> fetch(q), q -> count(q)));
add(g);
// filter omitted
final Button refresh = new Button("refresh");
refresh.addClickListener(e -> {
System.out.println("refresh clicked");
g.getDataProvider().refreshAll();
});
add(refresh);
add(new TextField("State check"));
}
// fake DataProvider
private int count(Query<Person, Void> q) { return 3; }
private Stream<Person> fetch(Query<Person, Void> q) {
q.getLimit(); //vaadin checks these have been called
q.getOffset(); //vaadin checks these have been called
System.out.println("fetching again");
new Exception().printStackTrace(); //figure out who called
return Arrays.asList(new Person("1"), new Person("2"), new Person("3")).stream();
}
}
My MainView is used to switch between GridView and EmptyView
#PreserveOnRefresh
public class MainView extends AppLayout {
private Component emptyBView;
private Component gridBView;
public MainView() {
final Button emptyB = new Button("Btn empty");
emptyB.addClickListener(e -> {
if (emptyBView == null) { emptyBView = new EmptyView();}
setContent(emptyBView);
});
addToNavbar(emptyB);
final Button gridB = new Button("Btn grid");
gridB.addClickListener(e -> {
if (gridBView == null) gridBView = new GridView();
setContent(gridBView);
});
addToNavbar(gridB);
}
}
MainView is an AppLayout used to switch the contents of the AppLayout from GridView to EmptyView and back.
Use Case 2 is: When returning to GridView, the GridView should be exactly same state as before (which works fine with the TextField).
open GridView -> grid should not be filled with data
enter filter params (not shown in code)
click "refresh" to populate the grid
enter "Spiderman" in TextField "stateCheck"
switch to EmptyView
in the real app: do something in EmptyView and potentially other views
return to GridView -> the grid should not reload the data, it should just stay as it was - just like the TextField still displays "Spiderman", the grid should display the same data as before without reloading it.
For Case 1: In the callback check if you have filter parameters, return an empty set if not. Using the new V17+ API it would look like this:
grid.setItems(query -> {
if(filterParameters.isEmpty()) {
// Return an empty stream
} else {
// Fetch from backend
}
});
You can read more in the docs here: https://vaadin.com/docs/latest/flow/binding-data/data-provider (V19) or https://vaadin.com/docs/v14/flow/binding-data/tutorial-flow-data-provider (V14)
I would need more info on what you're currently doing to help out with Case 2. How are you constructing the view, what does your code look like? A full stack trace with the "Caused by" would also help.
I would recommend only setting the DataProvider to the Grid once the first filter parameter is set. The client-side Grid expects to receive the number of items it requires from the fetch query; it might work in some corner case if you don't provide the requested numbers of items from fetch, but it's not designed to behave like that.
Note that this applies specifically to using DataProviders with filters in Vaadin 14 series - Vaadin 17 introduced a new optional simplified way of fetching items, which changes this equation a bit. It's not backported to Vaadin 14 yet (currently planned for 14.7).
I have two lists which are rendered by my directive. The requirement is that user can move an item from one list to another. I have a simplified implementation of this below:-
http://jsfiddle.net/yK7Lt/
The above shows a demo of how it should behave. Notice in this I manipulate the model and the DOM auto-syncs with it.
However, the problem is I am using jquery-ui-sortable plugin. So, the user can drag and drop the item from one list to another. Since jQuery is unaware of AngularJs so it modified the DOM. Now in my directive I have placed the code to sync the underlying model with the changed DOM.
The below jsfiddle code is a simplified version of my code.
http://jsfiddle.net/5Xuz2/1/
The relevant code snippet is:-
$('#btn').on('click', function () {
var li = $('#left li').first().detach();
$('#right').prepend(li);
console.log('moved top DOM to right list');
angular.element('#left').scope().$apply(function () {
// The moment this code runs, the DOM related to i is
// marked with $$NG_REMOVED, and is removed from page.
// Also somehow the DOM related to item D too is removed.
i = itemsl.shift(); // i is global variable.
});
angular.element('#right').scope().$apply(function () {
itemsr.unshift(i);
console.log('synced data with DOM');
});
});
The problem I am facing with my implementation is that the right list empties out as soon as I sync my left list model.
What is wrong with my implementation?
Is there a better approach?
the problem here is you are manipulating DOM with both Angular and jQuery... if you remove this piece of code
var li = $('#left li').first().detach();
$('#right').prepend(li);
it is working as expected
btw. I suggest trying angular-UI instead of jQueryUI
edit: OR you can try to refactor your code to something like this
var itemsl, itemsr, i, move;
function Model(name) {
this.name = name;
}
function Ctrl($scope) {
itemsl = $scope.itemsl = [new Model('A'), new Model('B'), new Model('C')];
itemsr = $scope.itemsr = [new Model('D')];
move = function() {
$scope.$apply(function() {
i = itemsl.slice(0,1);
itemsl.splice(0,1);
itemsr.unshift(i[0]);
i = null;
});
}
}
$(function () {
$('#btn').on('click', function () {
console.log('moved top DOM to right list');
move();
});
});
Couple of days ago I found this interesting post at http://www.smartjava.org/content/drag-and-drop-angularjs-using-jquery-ui and applied it into my website. However when I progressively using it there is a bug I identified, basically you can not move an item directly from one div to another's bottom, it has to go through the parts above and progress to the bottom. Anyone can suggest where does it goes wrong? The example is at http://www.smartjava.org/examples/dnd/double.html
Troubling me for days already.....
I did this a bit differently. Instead of attaching a jquery ui element inside the directive's controller, I instead did it inside the directive's link function. I came up with my solution, based on a blog post by Ben Farrell.
Note, that this is a Rails app, and I am using the acts_as_list gem to calculate positioning.
app.directive('sortable', function() {
return {
restrict: 'A',
link: function(scope, elt, attrs) {
// the card that will be moved
scope.movedCard = {};
return elt.sortable({
connectWith: ".deck",
revert: true,
items: '.card',
stop: function(evt, ui) {
return scope.$apply(function() {
// the deck the card is being moved to
// deck-id is an element attribute I defined
scope.movedCard.toDeck = parseInt(ui.item[0].parentElement.attributes['deck-id'].value);
// the id of the card being moved
// the card id is an attribute I definied
scope.movedCard.id = parseInt(ui.item[0].attributes['card-id'].value);
// edge case that handles a card being added to the end of the list
if (ui.item[0].nextElementSibling !== null) {
scope.movedCard.pos = parseInt(ui.item[0].nextElementSibling.attributes['card-pos'].value - 1);
} else {
// the card is being added to the very end of the list
scope.movedCard.pos = parseInt(ui.item[0].previousElementSibling.attributes['card-pos'].value + 1);
}
// broadcast to child scopes the movedCard event
return scope.$broadcast('movedCardEvent', scope.movedCard);
});
}
});
}
};
});
Important points
I utilize card attributes to store a card's id, deck, and position, in order to allow the jQuery sortable widget to grab onto.
After the stop event is called, I immediately execute a scope.$apply function to get back into, what Misko Hevery call,s the angular execution context.
I have a working example of this in action, up in a GitHub Repo of mine.
I want to be able to get a reference to the menu object that autocomplete builds, (so I can get the .attr("id") for example), but I'm not very familiar with jQuery/javascript. In the source, I found this:
https://github.com/jquery/jquery-ui/blob/1-9-stable/ui/jquery.ui.autocomplete.js#L182
so there is an object flying around, I just can't seem to find how to get hold of it.
So, for example, if I've got an input with an autocomplete bound to it like this:
// input = reference to the input text box on the form
input.autocomplete({
select: function(event, ui) {
// how to get the reference here?
// some things I've tried
// return input.menu
// return input.data("menu")
// and a few others but they didn't work either
}
});
I tried looking at the data object itself, but there were so many options I could spend all day looking at it and still not find what I'm looking for.
You can get the widget's reference by looking into dataset assigned to its root element (input). Then fetching menu property (and its underlying element) is kinda trivial. )
select: function(event, ui) {
// that's how get the menu reference:
var widget = $(this).data('ui-autocomplete'),
menu = widget.menu,
$ul = menu.element,
id = $ul.attr('id'); // or $ul[0].id
}
... as this within select function refers to the <input> when this function called as an event handler.
A simpler way to do this:
$(this).autocomplete('widget');
It does the same as:
select: function(event, ui) {
// that's how get the menu reference:
var widget = $(this).data('ui-autocomplete'),
menu = widget.menu,
$ul = menu.element,
id = $ul.attr('id'); // or $ul[0].id
}
It gives the ul list
$(this).autocomplete('widget').attr('id');
I'm stuck on one particular part of my project which consists of the components mentioned in the title.
I currently have a proof of concept that works the way I want it to work:
Sammy is integrated into the knockout viewmodels (as per the tutorial
on the knockout site)
the views are loaded on demand by a controller
(so I don't have to define every single view on the application page)
In my current situation I instance the viewmodels when the application starts (if I don't instance them, Sammy will not handle the routing). The problem is where the view is loaded and swapped by Sammy. I have to make a call to ko.applyBindings for KO to bind to the view. But its bad practice to repeatedly call applybingings.
My question, how do I bind to my views that are loaded on demand? I can't call ko.applybindings since that would create a memoryleak when the view is loaded more than once.
Here is an example VM with the offending ko.applyBindings:
function serviceInfoVm() {
var self = this;
self.ObjectKey = ko.observable();
self.Service = ko.observable();
self.LoadService = function () {
$.get('ServiceData/Detail', { serviceId: self.ObjectKey() }, function (data) {
self.Service(data);
});
};
$.sammy('#content', function () {
this.get('#/service/:id', function (context) {
var ctx = context;
self.ObjectKey(this.params['id']);
self.LoadService();
$.get('Content/ServiceInfo', function (view) {
ctx.app.swap(view);
ko.applyBindings(self);
});
});
}).run();
};
Anyone with some pointers and/or solutions to this problem?
You have the Sammy code in the viewmodel, which can work great if that viewmodel will be present and you want sub viewmodels and views to be loaded. So I assume that is what you are trying to do. Food for thought ... separate the sammy code into its own module (I call mine router in router.js) and let it manage the navigation separate from any viewmodel.
But back to your code ... you could set up your subviews and subviewmodels and use applybindings on them prior to the sammy.get being called. Basically, you are registering your routes in advance. Then the sammy.get just navigates to the new view, which is already data bound.
Not a solution but another approach:
Ended up abandoning the idea of loading the views dynamically.
Now my views are always present in the page and the visibility is triggered by this code:
var app = function () {
var self = this;
self.State = ko.observable('home');
self.Home = ko.observable(new homepageVm());
self.User = ko.observable(new userInfoVm());
$.sammy(function () {
this.get('#/', function (context) {
self.State('home');
});
this.get('#/info/:username', function (context) {
self.State('user');
self.User().UserName(context.params['username']);
self.User().LoadInfo();
});
}).run();
};
And the div visibility is triggered this way:
<div id="homeView" data-bind="with: Home, visible: State() === 'home'">
This way the ko.applyBindings only needs to be called once when the app starts.
The viewmodel above is bound to our shell page.
More on this here
Calling applyBindings on the specific element in the returned template is an option:
ko.applyBindings(viewModel, htmlNode)
Also see this question with regard to lazy loading templates: knockout.js - lazy loading of templates
And docs here for applyBindings: http://knockoutjs.com/documentation/observables.html