topic Re: How to display an evaluated expression? in Integration, Extension & APIs

How to display an evaluated expression?

nicolas_martin — Fri, 23 Jan 2015 09:41:53 GMT

Hello,

In an extension, the rendering is done in the "paint" function.

For instance:

paint : function($element, layout) { 
  $element.html("Hello World!") ; 
}

will display "Hello World!".

I would like to know how I can evaluate the string as a QlikView expression, something like that:

paint : function($element, layout) { 
  $element.html("=today()") ; 
}

paint : function($element, layout) { 
  $element.html("='you have ' & count(DISINTCT Element) & ' elements'") ; 
}

Thank you.

Re: How to display an evaluated expression?

ErikWetterberg — Fri, 23 Jan 2015 10:23:14 GMT

Hi,

You could set up an expression in your initial properties. Somthing like:

initialProperties : {
      version : {
                    qStringExpression : "=QlikViewVersion ()"
      },
      fields : {
                    qValueExpression : "=Count (DISTINCT $Field)"
                }
,......

this will give you version in the field layout.version and number of fields in layout.fields. If the values change, your paint method will be called again with the new values.

Erik

Re: How to display an evaluated expression?

nicolas_martin — Fri, 23 Jan 2015 11:08:22 GMT

I tried to add this lines in my "initialProperties", but I cannot access to the new "layout.fields" and "layout.version".

(I'm using Firebug to explore the object "layout")

I'm trying to modify the "HTML Box" object, so it could compute the string:

define(["jquery","./com-itelligence-htmlBox-properties"], function($,properties) {


  return {
  type : "it.HTML Box",
  //Refer to the properties file
  definition : properties,


  initialProperties : {
  version: 1.0,
  qHyperCubeDef : {
  qDimensions : [],
  qMeasures : [],
  qInitialDataFetch : [{
  qWidth : 0,
  qHeight : 0
  }]
  },
  fontSize : {
  min : 8,
  max : 24
  },
  test : {
  qStringExpression : "=QlikViewVersion ()"
  }
  },
  snapshot : {
  canTakeSnapshot : false
  },
  paint : function($element, layout) { 

  //$element.html("$(" + layout.qDef['HTML'] + ")") ; 
  $element.html(layout.test) ; 
  //$element.html(layout.qDef['HTML']) ; 
  }
  };
});

I've added a "test" property --> I can't access it with "layout.test".

My aim is to be able to set

='you have <b>' & count(DISTINCT $Field) & '</b> fields in your application'

in my HTML parameter, instead of a simple static string.

Re: How to display an evaluated expression?

ErikWetterberg — Fri, 23 Jan 2015 12:30:13 GMT

Since the initialProperties is used when you create the object, you need to recreate it.

Re: How to display an evaluated expression?

nicolas_martin — Fri, 23 Jan 2015 13:01:53 GMT

It works better for a static value.

However, if the value is hard-coded, the user can't change it.