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getData method

Information noteSTABLE.

This API is reliable and breaking changes are unlikely.

backendApi.getData(qPages)

Gets data from Qlik associative engine for this object.

Version history

Version history
Version state Details
Introduced 1.0

Parameters

qPages

Type: Array

An array of NxPage objects.

Returns

A promise of qDataPages.

Tip noteFor more information regarding a promise, see The Promise API.

Examples

Example:  

var self = this, requestPage = [{
		qTop : i + this.currpos,
		qLeft : 0,
		qWidth : 10, 
		qHeight : this.displayrows
	}];

this.backendApi.getData(requestPage).then(function(dataPages) {
	self.paint($element);
});

Example:  

In this example, the getData function get the cells defined by requestpage and returns them in the parameter dataPages. It also updates the layout buffer used by eachDataRow, so when the paint function is called again it will have all rows. This way, the visualization is build up gradually.
paint: function ( $element ) {
     var lastrow = 0, me = this;
     //loop through the rows we have and render
     this.backendApi.eachDataRow( function ( rownum, row ) {
                lastrow = rownum;
                //do something with the row..
     });
     if(this.backendApi.getRowCount() > lastrow +1){
             //we havent got all the rows yet, so get some more, 1000 rows
              var requestPage = [{
                    qTop: lastrow + 1,
                    qLeft: 0,
                    qWidth: 10, //should be # of columns
                    qHeight: Math.min( 1000, this.backendApi.getRowCount() - lastrow )
                }];
               this.backendApi.getData( requestPage ).then( function ( dataPages ) {
                        //when we get the result trigger paint again
                        me.paint( $element );
               } );
     }
 
}

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