Page History

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Purpose of this property type

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This was added in order to improve performance by removing the need for angular watches. You no longer need to add lots of angular watches, deep or collection watches in order to be aware of incoming server changes to the foundset property. Each such watch would slow down the page - as watches are triggered a lot for all kinds of user actions or socket traffic. Also the listener can give more detailed information in order to do more granular updates to the UI easier.

Look at this change listener from the client side foundset property's point of view, not from the server's point of view. For example a NOTIFY_FULL_VALUE_CHANGED does not necessarily mean that the server side foundset has changed by reference. It actually means that all client side contents of the foundset property did change - or might have changed. So it is meant to notify about changes in client side property value.

To add an incoming server change listener to this property type just call:

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myFoundset: {
    (...)
    viewPort: {
        startIndex: 15,
        size: 2,
        rows: [ { _svyRowId: 'someRowIdHASH1', dp1dp0: (...), dp2dp1: (...), dp3dp2: (...) },
                { _svyRowId: 'someRowIdHASH2', dp1dp0: (...), dp2dp1: (...), dp3dp2: (...) } ],
        (...)
    },
    (...)
}

Notice the fixed column names: dp0, dp1, dp2, ... dp[N-1] where N is the number of foundset dataproviders that the developer has chosen.

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The formatting information is similar to what default Servoy components get for their format properties, so it could be used in a similar way (for example through $formatterUtils; for more details check out the source code - servoyformat.js, textfield.js).

Defining initial load and listener options for a foundset property

A web component can specify in it's .spec file that initially, at first show or each time the foundset gets completely refreshed it wants to automatically receive a number of rows in the viewport. This is useful to avoid some round trips between client and server and send data directly. It is configurable because some components may want to send no records initially while others might need to send many. This is done via the initialPreferredViewPortSize option. Default value is 50.

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