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view on: demo kit nightly build | demo kit latest release

Suspend and Resume

A suspended binding does not send data service requests nor does it fire change events. You can resume a suspended list or context binding with its resume method.

You can suspend a list binding or context binding with its suspend method. You can only suspend absolute bindings or bindings which are quasi-absolute. A quasi-absolute binding is a relative binding with a context which is not a sap.ui.model.odata.v4.Context. You can only suspend a binding which is not yet suspended. For a relative binding having a V4 context, you may suspend the root binding of its binding hierarchy which is the (quasi-) absolute ancestor binding of this binding. The binding's method getRootBinding provides the root binding; for (quasi-) absolute bindings it returns the binding itself.

Typical use cases for suspend and resume are:

  1. Initiate read requests for controls in the view later; not when the view is initialized:

    In some situations you may want to suppress OData requests and change events initiated by an OData V4 binding for a certain period of time. This is useful for value help dialogs, such as the value help for the /BusinessPartnerList when creating a sales order in the SalesOrders OData V4 sample.

  2. Avoid intermediate request when modifying the binding multiple times

    You want to add a filter and change the sorting of a list binding. If the binding is not suspended, it will initiate a request after calling the filter method, and a second request after calling the sort method. If it is suspended, only one request with the updated filter and sort criteria is sent on resume.

The code below shows a snippet from the SalesOrders OData V4 sample which delays the request to /BusinessPartnerList until the Create Sales Order dialog is displayed.

Note:

The suspended flag in the binding info initiates a call to the suspend method of the corresponding binding once it is created.

Example:

View

<Dialog id="CreateSalesOrderDialog" title="Create New Sales Order">
...
    <Input id="NewBuyerID" suggestionItems="{path : '/BusinessPartnerList', suspended : true}">
        <suggestionItems>
            <core:ListItem key="{BusinessPartnerID}" additionalText="{CompanyName}"  text="{BusinessPartnerID}"/>
        </suggestionItems>
    </Input>
...
</Dialog>

The controller code to open the dialog resumes the list binding on /BusinessPartnerList and thus initiates the request.

Example:

Controller

var oBPListBinding = this.byId("NewBuyerID").getBinding("suggestionItems");
 
if (oBPListBinding.isSuspended()) {
    oBPListBinding.resume();
}

When a binding is suspended, all methods which may initiate CRUD requests for this binding, for example ODataListBinding.create, throw an error. This is also true for dependent bindings of a suspended binding. However methods that cause the binding to be refreshed completely are allowed. These methods are:

Caution:

It is not allowed to suspend operation bindings.