Version 3.17.2

Example: DataSource.Function

DataSource.Function allows the implementer to define a JavaScript function that returns data values, for maximum customizeability. A DataSchema plugin is used to normalize incoming data into a known format for consistency of usage by other components.

Array

Data
[
    {name:"abc",id:123},
    {name:"def",id:456},
    {name:"ghi",id:789}
]
Schema
{
    resultFields: ["name","id"]
}
Normalized data

JSON

Data
{
    "profile":{
        "current":160,
        "target":150
    },
    "reference": [
        {
            "category":"exercise",
            "type":"expenditure",
            "activities":[
                {"name":"biking", "calories":550},
                {"name":"golf", "calories":1000},
                {"name":"running", "calories":650},
                {"name":"swimming", "calories":650},
                {"name":"walking", "calories":225}
            ]
        },
        {
            "category":"nutrition",
            "type":"intake",
            "fruit":[
                {"name":"apple", "calories":70},
                {"name":"banana", "calories":70},
                {"name":"orange", "calories":90},
            ],
            "vegetables":[
                {"name":"baked potato", "calories":150},
                {"name":"broccoli", "calories":50},
                {"name":"green beans", "calories":30}
            ]
        }
    ],
    "program": [
        {
            "category":"exercise",
            "schedule":[
                {"day":"sunday", "activity":"swimming"},
                {"day":"monday", "activity":"running"},
                {"day":"tuesday", "activity":"biking"},
                {"day":"wednesday", "activity":"running"},
                {"day":"thursday", "activity":"swimming"},
                {"day":"friday", "activity":"running"},
                {"day":"saturday", "activity":"golf"}
            ]
        },
        {
            "category":"diet",
            "schedule":[
            ]
        }
    ]
}
Schema
{
    resultListLocator: "reference[1].fruit",
    resultFields: ["name","calories"]
}
Normalized data

Your custom function can return arbitrary data, so use the appropriate schema plugin to normalize the data into a consistent format. Array data would use a DataSourceArraySchema plugin:

YUI().use("datasource-function", "datasource-arrayschema", function(Y) {
    var myFunction = function(request) {
        return [
            {name:"abc",id:123},
            {name:"def",id:456},
            {name:"ghi",id:789}
        ];
    },
    myDataSource = new Y.DataSource.Function({source:myFunction}),
    myCallback = {
        success: function(e){
            alert(e.response);
        },
        failure: function(e){
            alert("Could not retrieve data: " + e.error.message);
        }
    };

    myDataSource.plug(Y.Plugin.DataSourceArraySchema, {
        schema: {
            resultFields: ["name","id"]
        }
    });

    myDataSource.sendRequest({callback:myCallback});
});

Whereas JSON data would use a DataSourceJSONSchema plugin:

YUI().use("datasource-function", "datasource-jsonschema", function(Y) {
    var myFunction = function(request) {
        return {
            "profile":{
                "current":160,
                "target":150
            },
            "reference": [
                {
                    ...
                },
                {
                    "category":"nutrition",
                    "type":"intake",
                    "fruit":[
                        {"name":"apple", "calories":70},
                        {"name":"banana", "calories":70},
                        {"name":"orange", "calories":90},
                    ],
                    "vegetables":[
                        {"name":"baked potato", "calories":150},
                        {"name":"broccoli", "calories":50},
                        {"name":"green beans", "calories":30}
                    ]
                }
            ],
            "program": [
                ...
            ]
        };
    },
    myDataSource = new Y.DataSource.Function({source:myFunction}),
    myCallback = {
        success: function(e){
            alert(e.response);
        },
        failure: function(e){
            alert("Could not retrieve data: " + e.error.message);
        }
    };

    myDataSource.plug(Y.Plugin.DataSourceJSONSchema, {
        schema: {
            resultListLocator: "reference[1].fruit",
            resultFields: ["name","calories"]
        }
    });

    myDataSource.sendRequest({callback:myCallback});
});