javajsonreportingbirtbirt-deapi

Nested loop in birt report

I'm using Eclipse Birt to generate report from a JSON File.

My JSON file look like this : 

{  
"cells":[  
  {  
     "type":"basic.Sensor",
     "custom":{  
     "identifier":[  
           {  
              "name":"Name1",
              "URI":"Value1"

           },
           {  
              "name":"Name4",
              "URI":"Value4"
           }
        ],
        "classifier":[  
           {  
              "name":"Name2",
              "URI":"Value2"
           }
        ],
        "output":[  
           {  
              "name":"Name3",
              "URI":"Value3"
           }
        ],

     },
           "image":{  
           "width":50,
           "height":50,
           "xlink:href":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAIAAAACACAYAAADDPmHLAAAABHNCSVQICAgIfAhkiAAAAAlwSFlzAABEJAAARCQBQGfEVAAAABl0RVh0U29mdHdhcmUAd3Vi8f+k/EREURQtsda2Or/+nFLqP6T5Ecdi0aJFL85msz2Qxyf4JIumMAx/ClmWt23GmL1kO54CXANAVH+WiN4Sx7EoNVkU3Z41BDHMeXAxjvOxNr7RJjzHX7S/jAflwBxkJr/RwiOpWZ883Nzd+Wpld7tkBr/SJr7ZHZbHZeuVweSnPfniocMAWYwcGBafH0OoPamFGAaY4ZBZjmmFGAaY4ZBZjmmFGAaY4ZBZjmmFGAaY7/B94QnX08zxKLAAAAAElFTkSuQmCC"
        }
     }
  },
  {  
     "type":"basic.Sensor",

     "custom":{  
        "identifier":[  
           {  
              "name":"Name1",
              "URI":"Value1"

           },
           {  
              "name":"Name4",
              "URI":"Value4"
           }
        ],
        "classifier":[  
           {  
              "name":"Name2",
              "URI":"Value2"
           }
        ],
        "output":[  
           {  
              "name":"Name3",
              "URI":"Value3"
           }
        ],

     },

        "image":{  
           "width":50,
           "height":50,
           "xlink:href":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAgAAAAIACAYAAAD0eNT6AAAACXBIWXMAAAsTAAALEwEAmpwYAAAKT2lDQ1BQaG90b3Nob3AgSUNDIHByb2ZpbGUAAHjanVNnVFPpFj333vRCS4iAlEtvUhUIIFJCi4AUkSYqIQkQSoghodkVUcERRUUEG8igiAOOjoCMFVEsDIoK2AfkIaKOg6OIisr74Xuja9igAQAAAgAIoAEAAAIACKABAAACAAigAQAAAgAIoAEAAAIACKABAAACAAigAQAAAgAIoAEAAAIADqhvprADeSsau00l5NAAAAAElFTkSuQmCC"
        }
     }
  },
  {  
     "type":"basic.Platform",

     "custom":{  
        "identifier":[  
           {  
              "name":"Name1",
              "URI":"Value1"

           }
        ],
        "classifier":[  
           {  
              "name":"Name2",
              "URI":"Value2"
           }
        ],
        "output":[  
           {  
              "name":"Name3",
              "URI":"Value3"
           }
        ],

        "image":{  
           "width":50,
           "height":50,
           "xlink:href":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAQAAAA6TH0jqtg6U8EsCdnm3SpevSK7Pb85xABEMBuLAn2hxjRve7SFzYEaB/HhytLQ4ABRwCWBPvBKnRk6U8EkBeOD9f7iwAGHAGEYEmwDxLvzNKfCCDP8NGLQd3lY7D0JwI4kmlwfHhX6dTSXxsRAAHsWR7aUjc7uM5Wg=="
        }
     }
  }
]
 }

i have 3 cells and each one contains 1 Image 1 Name 1 Type and 3 Tables , this is what i have done so far :enter image description here

what i'm struggling to do is a nested loop, i want to have for each object( Cell) in my JSON a paragraph numerated like this :

So to do this i need to itterate on each cell and then itterate on each table Output, identifier and classifier and i have no idea how can i do this, a nested loop. like a List which represent the number of cells, that contains 3 tables, one image , one name.

**Edit : ** this is the open method for the data set

// Grab the JSON file and place it in a string
fisTargetFile = new FileInputStream(new File("C:/Users/Sample Reports/moe.json"));
input = IOUtils.toString(fisTargetFile, "UTF-8");

// Store the contents in a variable
jsonData = input;

// Convert the String to a JSON object
myJSONObject = eval( '(' + jsonData + ' )' );

// Get the length of the object
len = myJSONObject.cells.length;

// Counter
count = 0;

Fetch method :

if(count < len) {
var name     = myJSONObject.cells[count].attrs.text["text"];
var type    = myJSONObject.cells[count].type;
var icon =myJSONObject.cells[count].attrs.image["xlink:href"];



icon = icon.split(",");

icon= icon[1];
imageDataBytes = icon;

row["name"]     = name;
row["type"]    = type;
row["icon"]    = Base64ToBlob.toBytes(icon);



Logger.getAnonymousLogger().info( row["icon"]);
count++;
return true;
}

return false;
Solution

  • You want to use nested tables, there is a good tutorial showing how to link nested tables to an outer table: please watch carefully this demo first, in particular see how the sub-table is linked to the outer table through a dataset parameter.

    Of course your case is more challenging because you need to do this with scripted datasets and multiple sub-tables. I already did something similar, you have to create one scripted dataset for each sub-table. Key-points are:

    That's it, it won't be easy but these elements should help to achieve this report.