Javascript to return value from client side data cache

[Julian Baker]

I have a FormView control using an EditorSet and and Editor-List to select values. I need to use the Lookup function to return the description for the corresponding ID that is selected in the Editor.

The Lookup feature gives the option of using a list or a javascript function:

alpha1.png


Using the list option works but some of the lists are quite large and slow the form down. Also as I have the information in the Client Side Data Cache for other purposes so I would like to use that instead. The problem is that I cannot work out how to write the Javascript function to return a value from the client side data cache for use by the FormView.

The getFromDataCache function works but is asynchronous so my function completes before any value is returned. I cannot work how to get the value and return it to the function used by the FormView to perform the lookup.

I have tried variations around the following with no success as there is nothing to return after the call to getFromDataCache:


alpha2.png

[alexc]

Re: Javascript to return value from client side data cache

hey Julian

You basically have it :) , only two changes would be to not have the return statement at the end and the filter. The return causes the lookup event function to end. This will almost always return nothing. Move the return line into the _onSuccess function then it should wait for the getFromDataCache function to do its thing and return data to the _onSuccess function which in turn will return the data to the Lookup event handler.

I also noticed your filter is not a function. I used a function as per the documentation i then received results in the success function.

The chrome debugger is your friend in these situations

getFromDataCache.PNG

[alexc]

Re: Javascript to return value from client side data cache

function ReadSeverity (e) {
 
    //alert('here:' + e);

	var _onSucess = function(data) {
		//debugger;
	    if (0 < data.length) {
			//handle empty array case
		} else {
			out = data[0].Country;
		    return out;
		}
	};
	
	var _filter = function(data) { 
	//debugger;
	if(data.Country == 'Germany') return true;
	else return false;
	}
	
	var _onFail = function() {
		//debugger;
	};

	if (e != ''){
	    var _filter = 'data.Country==' + e;
	    var _order = '';
		{dialog.object}.getFromDataCache('countries',_onSucess,_onFail,_filter);
	};
}

[Julian Baker]

Re: Javascript to return value from client side data cache

Hi Alex

Many thanks for your help on this.

Using your example I have got it to the point where the onSuccess function gets the value but this is not passed up to the main function. Although I have removed the return at the end of the main function it still seems to complete the function before any result is returned from the _onSuccess function and always returns blank.

function ReadSeverity (e) { 

var _onSuccess = function(data) {
		//debugger;
	    if (data.length<0) {
	      //handle empty array case
		} else {
			out = data[0].SevDescr;
			alert('found: ' + out);
		    return out;
		}
	};


var _onFail = function() { 
  out ='fail';
	       return out;
};

//var _filter = function(data) { 
//	//debugger;
//	if(data.SevID == 3) return true;
//	else return false;
//	}



if ( e != '') {
  var _filter='data.SevID=='+e ;
  {dialog.object}.getFromDataCache('Severity',_onSuccess,_onFail,_filter);
};


}

(Out of interest I have tried the filter as a function and a string and it seems to work the same way with either approach).

[alexc]

Re: Javascript to return value from client side data cache

Hey, Julian i will look at this again for you later and will let you know. in regards to the filter its weird it was always returning an empty array for me rather then the information expected in data. Can you send me a screen shot of how you are expecting the data to be seen on screen. Help me build out my test Formview UX i had built. This function fires a lot in the background.

[Julian Baker]

Re: Javascript to return value from client side data cache

Hey, Julian i will look at this again for you later and will let you know. in regards to the filter its weird it was always returning an empty array for me rather then the information expected in data. Can you send me a screen shot of how you are expecting the data to be seen on screen. Help me build out my test Formview UX i had built. This function fires a lot in the background.

I have a Formview that is designed for vehicle checks as follows:

alpha3.png

Most of the fields use an Editor-List to allow the user to pick the value from a list. The lists are based on tables that have a numeric ID and a description field (e.g. LocationID (int) and LocationDescr (varchar)). I have set these up in the Client Side Data Cache.

In the editor configuration genie I have the lists displaying the description field and returning the ID field. This all works well but I want to display the description field rather than the ID on the formview.

alpha4.png

I am therefore trying to use the Lookup feature within the form builder. This gives the option to lookup the description from a list or a Javascript function. As I already have the data in the Client Side Data Cache I am trying to use the javascript function from the previous post to perform this look up and return the description.

alpha5.png

The problem seems to be returning a value from the function as the call to get the data from the client side data cache is asynchronous and the function returns before the _onsuccess function does (the _onsuccess function does return a value so the call to get the data is working - it just does not return a value to the main function).

I am beginning to wonder if I am taking the wrong approach to this and maybe there is an easier solution!

Thanks