syncfusion ej grid javascript method - syncfusion

I am very new to syncfusion controls for mvc. While exploring how to set dynamic datasource to grid, I came across this line of javascript code which I cannot understand. I have been through the javascript api docs for ej grid but couldn't find the meaning.
var obj = $("#Grid").ejGrid("instance");
If someone can explain the meaning and point out some reference documentation, I will be highly grateful.
The example I came across
https://help.syncfusion.com/aspnetmvc/grid/how-to
The javascript api I have been through
https://help.syncfusion.com/api/js/ejgrid#members:datasource
P.s: I know from a comment I came across that this has something to do with current instance of ej grid but I would like a solid understanding via a reference so I can understand.

From my little experience with Syncfusion controls the documentation explaining how to perform tasks is not well stated. If you have a license you can ask questions in their forum but I can tell you what little I learned perusing their forum.
In their JS 1 version
var obj = $("#Grid").ejGrid("instance");
and in their JS 2 version
var obj = document.getElementById('Grid').ej2_instances[0];
The variable obj appears to get an object reference to the grid identified by the id Grid. I am not sure what the instance value refers to other than the examples in the documentation show it and it works when it is used.
Not sure if I was much help.

In the Below code example Grid – Grid ID and you can take the Grid instance using the above code example. From the instance you can get the details regarding the column, dataSource, filterSettings, sortSettings etc currently applied to ejGrid. We have given support to customize the Grid using several public method. You can call those method by taking the Grid instance.
#(Html.EJ().Grid<EJGrid.Models.Order>("Grid")
.Datasource((IEnumerable<object>)ViewBag.datasource)
.AllowPaging()
.Columns(col =>
{ col.Field("OrderID").HeaderText("Order ID").TextAlign(TextAlign.Right).Width(75).Add();
col.Field("EmployeeID").HeaderText("Employee ID").TextAlign(TextAlign.Right).Width(90).Add();
col.Field("Freight").HeaderText("Freight").Format("{0:c}").TextAlign(TextAlign.Right).Width(90).Add();
col.Field("ShipCity").HeaderText("Ship City").Width(90).Add();
col.Field("Child.Test").HeaderText("TEst").Format("{0:c}").Width(90).Add();
col.Field("ShipCountry").HeaderText("Ship Country").Width(90).Add();
})
)
<script>
var obj = $("#Grid").ejGrid("instance");
var value = $("#colValue").val();
//Add custom parameter to the server
var query = new ej.Query().addParams("EmployeeID", value);
//Creating ejDataManager with UrlAdaptor
var dataManager = ej.DataManager({ url: "/Home/GetData", adaptor: new ej.UrlAdaptor() });
var promise = dataManager.executeQuery(query); promise.done(function (e) {
//Assign the result to the grid dataSource using "dataSource" method.
obj.dataSource(e.result);
</script>
To update the Grid, you can use dataSource() method. To call that method you need to take the Grid instance and call that method.
Refer the below API documentation for your reference
https://help.syncfusion.com/api/js/ejgrid#methods:datasource - used to update the Grid dataSource dynamically
https://help.syncfusion.com/api/js/ejgrid#members:datasource - returns the Grid dataSource.
Please get back to us if you have further queries.

Related

How to convert List<Objects> to an ObservableRangeCollection

I am using Xamarin Forms and their templates come with MvvMHelpers object to be used in the ViewModel as ObservableRangeCollections. I know ObservableCollections. If you try to do :
ObservableRangeCollection<Object> collection = new ObservableRangeCollection<Object>();
List<Object> objects = new List<Objects>();
collection.ReplaceRange(objects);
//error invalid type
Does anyone know how to use an ObservableRangeCollection? There is nothing on it in Google, Bing or StackOverflow.
Try the search you'll see Xamarin is promoting something so new that nobody knows what it is.
ObservableRangeCollection is a helper class by the Xamarin Evangelist James Montemagno.
The source is available in his github:
https://github.com/jamesmontemagno/mvvm-helpers
ObservableRangeCollection intends to help when adding/replacing Collections to a ObservableCollection.
In a "regular" ObservableCollection, for each new item added to the Collection, a OnCollectionChanged event would raise.
This is where ObservableRangeCollection gets in. It allows to replace/add elements to the Collection without firing an event for each element.
ObservableRangeCollection is subclassed from ObservableCollection.
So in your example, substitute your <T>, i.e:
ObservableRangeCollection<string> collection = new ObservableRangeCollection<string>();
List<string> objects = new List<string>();
collection.ReplaceRange(objects);
Consult the code here: https://github.com/jamesmontemagno/mvvm-helpers/blob/master/MvvmHelpers/ObservableRangeCollection.cs
This is not something that new. There's plenty of code using ObservableCollection.
What you are trying to achieve can be done like this:
List<Object> myList = new List<Objects>();
ObservableCollection<Object> myCollection = new ObservableCollection<Object>(myList);
Read more about ObservableCollection.
Check out my answer here, which is an enhanced version of ObservableRangeCollection optimized for less event raising and reuse of items in UI.

SAPUI5 bindAggregation complete for a Table

I am binding an aggregation to a table . I couldn't find an event which is triggered after the binding is complete . There is "updateFinished" event for sap.m.List , which is exactly what I am looking for in a Table (and a dropodown). I thought of using attachRequestCompleted() on the model , but the model is used at other places where I do not want this event to trigger.
Is there anyway to trigger a event once the databinding is complete on a Table (and a dropdown)?
Any help is appreciated.
Thanks in advance.
update: There is "updateFinished" event for table extended from ListBase. I am still not sure how I missed it before I posted this question. But, the question is still valid for a dropdown and TableSelectDialog controls.
I also stumbled upon that problem, but in a different Context.
I have a Grid layout in which I dynamically load Panels via an oData Model.
Therefore I have entered the path in my XML Grid-View element.
<l:Grid id="grid" content="{some path...}">...</l:Grid>
Now I wanted to set the grid view busy and when the data is loaded revert this.
Therefore I use the Binding of the grid view.
In the Controllers onInit method I have added:
this._oGrid = this.getView().byId("grid");
this.getRouter().attachRouteMatched(this._onRouteMatch.bind(this));
Please note that the bind method is not available in every browser. You need to apply a polyfill. (See https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/Function/bind)
Also Bind has nothing to do with the binding :D
I needed to do this because the Binding is not available in the onInit function.
The _onRouteMatched function:
var oContent = this._oGrid.getBinding("content");
oContent.attachDataReceived(function(oData) {
this._oGrid.setBusy(false);
}.bind(this));
Now when the data is received the busy option is set to false.
If you want to show a 'loading' indicator for your table while the data is still loading (and thus not bound), I think the best approach is the following:
Use a dedicated JSONModel which holds only UI-specific stuff, like toggling enabled/readonly/busy/etc properties of controls.
In your case, something like:
var oUIModelData = {
tableIsBusy : false,
//etc, things like :
btnSubmitEnabled : false,
someControlVisible : true
};
var oUIModel = new sap.ui.model.json.JSONModel();
oUIModel.setData(oUIModelData);
sap.ui.getCore().setModel(oUIModel, "UIModel");
In your table definition, bind the busy property to {UIModel>/tableIsBusy} and set the table's property busyIndicatorDelay to 0 to avoid any delays
Just before you do your OData service call, set the property tableBusy to true. This will immediately show the busy overlay to your table:
sap.ui.getCore().getModel("UIModel").setProperty(tableIsBusy, true);
//here your OData read call
In your OData service's requestCompleted (and if needed, also in requestFailed) event handlers, set the busy property of the UIModel back to false:
sap.ui.getCore().getModel("UIModel").setProperty(tableIsBusy, false);
The big benefit of this approach is (IMHO) instead of relying on each control to check whether the data has been loaded, simply do it during the actual load.
And by binding these UI-related things to a (separate) model saves you from writing lots of extra code ;-)
In general you could solve the problem by using batch processing on the OData service. According to https://sapui5.netweaver.ondemand.com/docs/guide/6c47b2b39db9404582994070ec3d57a2.html:
Use OData model v2.
var oModel = new sap.ui.model.odata.v2.ODataModel(myServiceUrl);
Define a set of deferred batch groups.
oModel.setDeferredBatchGroups(["myGroupId", "myGroupId2"]);
Add the batch group information to the corresponding bindings, e.g:
{
path:"/myEntities",
parameters: {
batchGroupId: "myGroupId"
}
}
All read/query actions on bindings in a certain batch group will be held back until a .submitChanges(.) call on the batch group is made.
oModel.submitChanges({
batchGroupId: "myGroupId",
success: mySuccessHandler,
error: myErrorHandler
});
Use the success/error handlers to execute actions.
This rather generic approach gives you additional control such as trigger actions, grouping and event handling on the OData model.

GWT-OpenLayers and OpenLayers.Format.WMSCapabilities

I am working with the Google Web Toolkit wrapper for OpenLayers. I'm attempting to add a WMS layer to a map, but I need to parse a Capabilities document in order to get the available layer names. I see that a WMSCapabilities class is available in OpenLayers http://dev.openlayers.org/releases/OpenLayers-2.12/doc/apidocs/files/OpenLayers/Format/WMSCapabilities-js.html, but I can't seem to find the implementation in GWT. Is this feature not yet available, or is it hiding, undocumented somewhere? Thanks in advance!
I still don't know if the GWT implementation is available, but it's actually rather easy to wrap native javascript code in Java. Here is my solution:
import com.google.gwt.core.client.JsArrayString;
native JsArrayString getLayerNames(String capDoc) /*-{
var toReturn = [];
var parser = new $wnd.OpenLayers.Format.WMSCapabilities();
var doc = parser.read(capDoc);
for (var i in doc.capability["layers"]) {
toReturn.push(doc.capability["layers"][i].name);
}
return toReturn;
}-*/;
You can then access them using:
JsArrayString layers = getLayerNames(getMyCapabilitiesDocumentAsString());
for (int i = 0; i < layers.length(); i++) {
Window.alert("A layer name is " + layers.get(i));
}
The variable doc is a javascript array containing the entire contents of the capabilities document, so it's possible to access more than just the layer names; simply pull out what you need. Also, it's probably better to create a single parser rather than create a new one each time the method is called, but that's a different exercise ;)

YUI3 DOM is undefined?

I am newcomer to Javascript and have been tasked with migrating our product's UI from YUI2 to YUI3.
It doesn't look like there's a migration guide anywhere, so I'm browsing internet posts and the yui docs for now.
In my global scope, I've temporarily added something like var Y = YUI().use('*',function(Y){});
I've encountered a YAHOO.util.Dom.get(...) elsewhere which doesn't work with YUI3, and it looks like Y.DOM.byId(...) is the recommended migration. But, I'm getting the error that "Y.DOM" is undefined!
Whoever's using Y.DOM.(...), how did this get resolved?
I don't know where you found the idea of Y.DOM.byId
Try
var node = Y.one('#elementID');
or if you want to use classes:
var nodes = Y.all('.className');
For more information on how to get nodes in YUI3, see their documentation
EDIT:
<script>
YUI().use('node', function (Y) {
var node = Y.one('#elementID');
});
</script>

GXT (Ext-GWT) + Pagination + HTTP GET

I'm trying to populate a GXT Grid using data retrieved from an online API (for instance, going to www.example.com/documents returns a JSON array of documents). In addition, I need to paginate the result.
I've read all the various blogs and tutorials, but most of them populate the pagination proxy using something like TestData.GetDocuments(). However, I want to get that info using HTTP GET.
I've managed to populate a grid, but without pagination, using a RequestBuilder + proxy + reader + loader. But it seems as though the actual loading of the data is "put off" until some hidden stage deep inside the GXT code. Pagination requires that data from the start, so I'm not sure what to do.
Can someone provide a simple code example which does what I need?
Thank you.
I managed to get this going, here is what I did:
First I defined the proxy and loader for my data along with the paging toolbat:
private PagingModelMemoryProxy proxy;
private PagingLoader<PagingLoadResult<ModelData>> loader;
private PagingToolBar toolBar;
Next is the creation of each one, initializing with an empty ArrayList.
proxy = new PagingModelMemoryProxy(new ArrayList<EquipmentModel>());
loader = new BasePagingLoader<PagingLoadResult<ModelData>>(proxy);
loader.setRemoteSort(true);
toolBar = new PagingToolBar(100);
toolBar.bind(loader);
loader.load(0, 100);
Last, I have a set method in my view that gets called when the AJAX call is complete, but you could trigger it anywhere. Here is my entire set method, Equipment and EquipmentModel are my database and view models respectively.
public void setEquipmentData(List<Equipment> data)
{
Collections.sort(data);
// build a list of models to be loaded
List<EquipmentModel> models = new ArrayList<EquipmentModel>();
for (Equipment equipment : data)
{
EquipmentModel model = new EquipmentModel(equipment);
models.add(model);
}
// load the list of models into the proxy and reconfigure the grid to
// refresh display.
proxy.setData(models);
ListStore<EquipmentModel> equipmentStore = new ListStore<EquipmentModel>(loader);
equipmentGrid.reconfigure(equipmentStore, equipmentColumnModel);
loader.load(0, 100);
}
The key here for me was re-creating the store with the same loader, the column model was pre-created and gets reused.