{dialog.object}getFromDataCache Method
Syntax
Arguments
- UXClientSideDataCacheItem
A comma delimited list of data items to get. Can also be '*all' to get all data items.
- onSuccess
A javascript function that is called when the data is successfully retrieved.
- onFail
Optional. A javascript function that is called if the data cannot be retrieved. EG, if an ajax callback must be made to a server to fetch the data but no network connection is available.
- filter
Optional. A Javascript expression that returns true/false. The expression can reference data in the array using this syntax: data.fieldname (case-sensitive.) filter can also be a Javascript function that takes 'data' as an input parameter and return true/false.
- order
Optional. Can be a Javascript object that defined the sort order, or a Javascript function. See example below.
- optionsObject
Optional. A JSON object containing additional options. The object can contain these properties:
- columns
array of columns to return from the data cache item
- distinct
true/false - indictates if distinct values should be returned
- distinctColumn
The name of the column to check for distinct values. If omitted, first column in the data is assumed to be the distinct column.
Description
Reads an item in the client-side data cache. Makes an ajax callback to the server to download the data if it isn't already in the cache.
Discussion
The getFromDataCache method reads an item in the client-side data cache. Once the data has been read, the onSuccess function is called. If data hasn't been loaded in the client-side cache, an ajax callback is made to the server to retrieve the data. You can specify an optional filter and/or order to apply to the data before the onSuccess function is called. The onSuccess function is passed an array of objects representing the data in the data cache.
//read data from a data-cache item called 'customer'
var _onSuccess = function(data) {
alert('Rows in data item: ' + data.length);
};
var _onFail = function() {
};
//filter expression references the 'Country' field in the data item. If expression
//returns true, the row is include in the output array
var _filter = 'data.Country == "USA" || data.Country = "France"';
//no sorting
var _order = '';
{dialog.object}.getFromDataCache('customers',_onSuccess,_onFail,_filter,_order);
//examples of more complex filter and order definitions
//a filter function
var _filter = function(data) {
if(data.City == 'Boston') return true;
else return false;
}
//sort by City in ascending order
var _order = {'City' : 1};
//sort by City, then by Lastname (descending)
var _order = {'City' : 1, 'Lastname': -1};
//an order function that sorts by Lastname, then by DOB ( a date field with a format of MM-dd-yyyy) in descending order
var _order = function(a,b) {
if(a.Lastname > b.Lastname) return 1;
else if(a.Lastname < b.Lastname) return -1;
else {
if(new Date().fromFormat(a.DOB:date:MM-dd-yyyy,'') > new Date().fromFormat(b.DOB:date:MM-dd-yyyy,'')) return 1;
else return -1;
}
}
{dialog.object}.getFromDataCache('customers',_onSuccess,_onFail,_filter,_order);
//only get distinct 'Country' field
var obj = {columns: ['Country'], distinct: true, distinctColumn: 'Country'};
{dialog.object}.getFromDataCache('customers',_onSuccess,_onFail,_filter,_order,obj);