Foundset property type

Purpose of this property type

The 'foundset' property type can be used by web components to access/change a foundset's data/state directly from the browser.

The foundset typed property in the browser will work based on a 'viewport' of the server's foundset. The viewport is controlled directly by the component's code. Server will adjust foundset viewport bounds/contents only when needed due to data changes, deletes, inserts...

The foundset property also gives the possibility of knowing/changing the selection of the foundset.

For advanced uses, the foundset property can be linked to/interact with other property types (dataprovider, tagstring, component, ...), so that those other properties will provide a viewport as well - representing the same rows/records as in the foundset's viewport. The properties that support foundset view of data will allow the web component to specify a "forFoundset: "[foundsetPropertyName]" in their own property's description in the .spec file.

For foundset property types Servoy Developer allows (in properties view) one of the following:

• a (parent) form's foundset
• a related foundset
• a separate foundset (of any table; smilar to JSDatabaseManager.getFoundset()). When this option is chosen the user can also choose whether or not the separate foundset should load all records initially. (if not checked, contents can be loaded at any time from scripting)

Foundset property value in browser

In browser js, a foundset property value has the following content:

myFoundset: {
    serverSize: 44, // the size of the foundset on server (so not necessarily the total record count
                    // in case of large DB tables)
    viewPort: {
        // this is the data you need to have loaded on client (just request what you need via provided
        // loadRecordsAsync or loadExtraRecordsAsync)
        startIndex: 15,
        size: 5,
        rows: [ { _svyRowId: 'someRowIdHASH1', name: "Bubu", type: 2 },
                { _svyRowId: 'someRowIdHASH2', name: "Ranger", type: 1 },
                { _svyRowId: 'someRowIdHASH3', name: "Yogy", type: 2 },
                { _svyRowId: 'someRowIdHASH4', name: "Birdy", type: 3 },
                { _svyRowId: 'someRowIdHASH5', name: "Wolfy", type: 4 } ]
    },
    selectedRowIndexes: [16], // array of selected records in foundset; indexes can be out of current
                              // viewPort as well
    multiSelect: false, // the multiselect mode of the server's foundset; if this is false,
                        // selectedRowIndexes can only have one item in it
    hasMoreRows: false, // if the foundset is large and on server-side only part of it is loaded (so
                        // there are records in the foundset beyond 'serverSize') this is set to true;
                        // in this way you know you can load records even after 'serverSize' (requesting
                        // viewport to load records at index serverSize-1 or greater will load more
                        // records in the foundset)
    columnFormats: { name: (...), type: (...) }, // columnFormats is only present if you specify
                        // "provideColumnFormats": true inside the .spec file for this foundset property;
                        // it gives the default column formatting that Servoy would normally use for
                        // each column of the viewport - which you can then also use in the browser yourself

    /**
     * Request a change of viewport bounds from the server; the requested data will be loaded
     * asynchronously in 'viewPort'
     *
     * @param startIndex the index that you request the first record in "viewPort.rows" to have in
     *                   the real foundset (so the beginning of the viewPort).
     * @param size the number of records to load in viewPort.
     */
    loadRecordsAsync: function(startIndex, size),

    /**
     * Request more records for your viewPort; if the argument is positive more records will be
     * loaded at the end of the 'viewPort', when negative more records will be loaded at the beginning
     * of the 'viewPort' - asynchronously.
     *
     * @param negativeOrPositiveCount the number of records to extend the viewPort.rows with before or
     *                                after the current loaded records.
     */
    loadExtraRecordsAsync: function(negativeOrPositiveCount),
 
    /**
     * Sort the foundset by the dataproviders/columns identified by sortColumns.
     *
     * The name property of each sortColumn can be filled with the dataprovider name the foundset provides
     * or specifies. If the foundset is used with a component type (like in table-view) then the name is the
     * name of the component on who's first dataprovider property the sort should happen. If the foundset
     * is used with another foundset-linked property type (dataprovider/tagstring linked to foundsets) then
     * the name you should give in the sortColumn is that property's 'idForFoundset' value (for example a
     * record 'dataprovider' property linked to the foundset will be an array of values representing the
     * viewport, but it will also have a 'idForFoundset' prop. that can be used for sorting in this call).
     *
     * @param {JSONArray} sortColumns an array of JSONObjects { name : dataprovider_id,
     *                    direction : sortDirection }, where the sortDirection can be "asc" or "desc".
     */
    sort: function(sortColumns),
 
    /**
     * Request a selection change of the selected row indexes. Returns a promise that is resolved
     * when the client receives the updated selection from the server. If successful, the array
     * selectedRowIndexes will also be updated. If the server does not allow the selection change,
     * the reject function will get called with the 'old' selection as parameter. 
     *
     * If requestSelectionUpdate is called a second time, before the first call is resolved, the
     * first call will be rejected and the caller will receive the string 'canceled' as the value
     * for the parameter serverRows.
     * E.g.: foundset.requestSelectionUpdate([2,3,4]).then(function(serverRows){},function(serverRows){});
     */
    requestSelectionUpdate : function(selectedRowIdxs),
 
    /**
     * Sets the preferred viewport size on the server for this foundset, so that the next (initial) load
     * will give back that viewport. Use this when the component resizes itself and doesn't know initially 
     * what it can show before hand.
     */
    setPreferredViewportSize: function(size)

}

• serverSize is controlled by the server; you should not change it

• viewPort initially has size 0, and startIndex 0. When the component detects that records are available (serverSize > 0) it care request viewPort contents using one of the two load async methods
  • viewPort.startIndex and viewPort.size will have the values requested by the async load methods. But if for example you are using data at the end of the foundset and records are deleted from there then viewport.size will be corrected/decreased from server (as there aren't enough records). A similar thing can happen to viewPort.startIndex. Do not modify these directly as that will have no effect. Use the load async methods instead.
  • viewPort.rows contains the viewPort data. Each item of the array represents data from a server-side record. Each item will always contain a "_svyRowId" ($foundsetTypeConstants.ROW_ID_COL_KEY in angular world) entry that uniquely identifies the record on server. Then there's one entry for every dataprovider that the component needs to use (how those are selected is described below). You should never change the "_svyRowId" entry, but it is possible to change the values of any of the other entries - the new values will be pushed back into the server side record that they belong to (if pushToServer is set on the foundset property to allow/shallow or deep; see "Data synchronization" section of https://wiki.servoy.com/display/public/DOCS/Specification).
• selectedRowIndexes is an array of selected foundset record indexes. This can get updated by the server if foundset selection changes server side. You can change the contents of this array to change foundset selection (new selection will be pushed to server). However, the preferred way of changing the record selection is by using "requestSelectionUpdate".
• multiselect represents the foundset multiselect state; do not change it as it will not be pushed to server.
• columnFormats represents the default column formats for the columns given in the viewport; do not change this - only server pushes this information to the client if asked to do so by the .spec file. It is only present if you specify "provideColumnFormats": true inside the .spec file for this foundset property.
• hasMoreRows true if the server side foundset has loaded only a part/chunk of it's records (in case of very large foundsets). In that case there are records even after 'serverSize'.  It is controlled and updated by the server; you should not change it.

Defining/using a foundset property with a random set of dataproviders

A web component might want to work with as many dataproviders available in the viewport as the developer wants. Servoy Developer will allow selecting any number of dataproviders of the foundset to be sent to browser web component property value (through the properties view for the foundset typed property; use sub-property 'dataproviders').

For example a component that shows graphical representation of data might allow adding as many 'categories' to it as the developer wants to (each category getting data from one viewport column/dataprovider) .

.spec file

"myFoundset": { "type": "foundset", "dynamicDataproviders": true }

So the component has a property called "myfoundset" that it wants linked to any foundset chosen in ServoyDeveloper, and it allows the developer to choose in properties view any number of dataproviders from the foundset.

browser js

Let's say the developer has chosen a foundset and 3 dataproviders (for example 3 database columns) from it. Those would generate for example a viewPort like this inside the browser property.

myFoundset: {
    (...)
    viewPort: {
        startIndex: 15,
        size: 2,
        rows: [ { _svyRowId: 'someRowIdHASH1', dp1: (...), dp2: (...), dp3: (...) },
                { _svyRowId: 'someRowIdHASH2', dp1: (...), dp2: (...), dp3: (...) } ],
        (...)
    },
    (...)
}

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

Defining/using a foundset property with a fixed set of dataproviders

A web component can specify in it's .spec file that it requires a foundset property and a fixed number of dataproviders from it. The foundset and required dataproviders are then selected by the developer when creating a solution (using the properties view, 'dataproviders' sub-property).

.spec file

"myFoundset": { "type": "foundset", "dataproviders": ["firstName", "lastName"] }

So the component has a property called "myfoundset" that it wants linked to any foundset chosen in ServoyDeveloper, and it needs two dataproviders from that foundset to be present in the foundset's property viewport.

browser js

Let's say the developer has chosen a foundset and selected for "firstName" a foundset dataprovider (for example a database column called parentFirstName) and for lastName another dataprovider (for example a database column called parentLastName). Those would generate for example a viewport like this inside the browser property:

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

In this way any foundset dataprovider/column can be mapped to one of the two dataproviders that the component requires. The actual foundset dataprovider name is not even used in browser js.

Defining/using a foundset property that provides default formatting information for columns

A web component can specify in it's .spec file that it requires the foundset property to provide default formatting information for it's columns. We will use a foundset property with fixed number of dataproviders as an example, but it will work the same for other ways of specifying the dataproviders.

.spec file

"myFoundset": { "type": "foundset", "dataproviders": ["image", "age"], "provideColumnFormats": true }

So the component has a property called "myfoundset" that it wants linked to any foundset chosen in ServoyDeveloper, and it needs two dataproviders from that foundset to be present in the foundset's property viewport. For each of the two columns it will also receive default formatting information.

browser js

Let's say the developer has chosen a foundset and selected for "image" a foundset dataprovider (for example a database column called 'photo') and for age another dataprovider (for example a database column called 'estimatedStructureAge'). Those would generate a viewport and formatting information similar to the following inside the browser property (note that the column format actual contents might change as needed - this is what Servoy default components receive as well for their component properties):

myFoundset: {
    (...)
    viewPort: {
        startIndex: 15,
        size: 2,
        rows: [ { _svyRowId: 'someRowIdHASH1', image: (...), age: (...) },
                { _svyRowId: 'someRowIdHASH2', image: (...), age: (...) } ],
        (...)
    },
    columnFormats: {
        image: {
            placeHolder: null,
            maxLength: 2147483647,
            isNumberValidator: false,
            edit: null,
            isMask: false,
            display: null,
            type: "MEDIA",
            allowedCharacters: null
        },

        age: {
            placeHolder: null,
            percent: "%",
            isNumberValidator: false,
            edit: null,
            isMask: false,
            display: "#,#00.###",
            type: "NUMBER",
            allowedCharacters: null
        }
    }
}

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).

Linking other "foundset aware" property types to a foundset property

Other property types can have content that is 'linked' to foundset records in some way. These property types can be configured in the .spec file as shown below - linking to any other property they have defined with 'foundset' type. When they are linked to a foundset, their javascript value in the browser is no longer only one value, but a viewPort of values (or it will also contain a viewPort of values - the exact content is property type specific) - corresponding to the records loaded in the linked foundset property's viewPort.

In this scenario, the viewPort of the foundset value only contains '_svyRowId' if it's own .spec property configuration doesn't list a dynamic or static list of dataproviders ("dataproviders" : [...] or "dynamicDataproviders": true), and the "foundset aware" property type value will have the viewPort contents in it (check each "foundset aware" type to see how that works, as it could differ from type to type).

Component type (child components that are linked to a foundset - for tables, lists, ...) or custom object types built of/containing other "foundset aware" property types (let's call them 'configurations' - can be used to build lightweight pure HTML tables, lists, ...) are the most common uses in this area.

Examples of foundset aware types are 'component', 'dataprovider', 'tagstring'.

.spec file

One child component linked to the foundset:

"myFoundset": "foundset",
"childElement" : { "type" : "component", "forFoundset": "myFoundset" }

Multiple child components (array of them, notice 'elementConfig' that specifies a config value for each contained element) linked to the foundset. This type of linking is currently used by Servoy's tableviews, listviews and portals:

"myFoundset": "foundset",
"childElements" : { "type" : "component[]", "elementConfig" : {"forFoundset": "myFoundset"} }

Have a look at 'component' page to see how these two properties above will look like in browser js.

'Configuration' object for sending other "foundset aware" types as viewPorts follows. In this case the value of those properties - so for example 'myconfigurations[0].mydataprovider' or 'myconfiguration.mydataprovider' will be arrays representing the foundset's viewport, not simple values. If the property is really linked to the record (so not global/form variables but record DP/column) then it will get a special 'idForFoundset' value - for example 'myconfiguration.mydataprovider.idForFoundset' - in it as well; that can be used with the foundset property's sort API. (Note: that "forFoundset" usage for "dataprovider" does not yet allow changing the value, but there is a case for making that work)

"myFoundset": "foundset",
"myconfiguration": "MyConfig", // or:
"myconfigurations": "MyConfig[]"
(...)
"types": {
    "MyConfig": { 
        "mydataprovider" : { "type" : "dataprovider", "forFoundset": "myFoundset"}
        "mytagstring" : { "type" : "tagstring", "forFoundset": "myFoundset"}
    }
}

Runtime property access

At runtime, the foundset property is accessible in (server-side) javascript. If a bean named "myFoundsetBasedBean" has a foundset property named "myFoundset" it can be accessed like this:

elements.myFoundsetBasedBean.myFoundset

That property gives access in scripting to the real underlying foundset as well as to the dataproviders that the property will send to the client webcomponent (dataproviders contains key-value pairs where key is the name of the column used in web component client side scripting and value is the name of the foundset column attached to that). Both foundset  and dataproviders are read-write values. Examples:

// elements.myFoundsetBasedBean.myFoundset.foundset gives access to the
// underlying Servoy foundset used by this property
application.output(elements.myFoundsetBasedBean.myFoundset.foundset.getSelectedIndex())
elements.myFoundsetBasedBean.myFoundset.foundset.loadRecords(someQBSelect)

// elements.myFoundsetBasedBean.myFoundset.dataproviders gives access to the
// configured dataproviders of the Servoy foundset property; probably most useful
// in combination with dynamicDataproviders: "true"
elements.myFoundsetBasedBean.myFoundset.dataproviders = {
	dp1: "userNickname",
	dp2: "userReviewRating",
	dp3: "numberOfPurchasedItems"
}
if (!elements.myFoundsetBasedBean.myFoundset.dataproviders.rating)
	elements.myFoundsetBasedBean.myFoundset.dataproviders.rating = "userReviewRating";