Hello! I have a JSON datasource in this format:
{
"data": [
{
"id": 0,
"images": ["IMAGE_0", "IMAGE_2"]
},
{
"id": 1,
"images": ["IMAGE_1"]
},
{
"id": 2,
"images": null
}
]
}I create subreport for each value in images array and assign this value to a field named "node". So I have subreports 0 with node = "IMAGE_0", 1 with node = "IMAGE_2", 2 with node = "IMAGE_1" and 3 with node = null. These subreports contains image elements. I am using parameters IMAGE_0, IMAGE_1, ..., IMAGE_N to pass byte data of images from my Java code. I want first subreport to use $P{IMAGE_0} and $P{IMAGE_2} as source expressions for image content. How can I create expressions like this given "node" fields? Something like $P{$F{node}} which would be evaluated to $P{IMAGE_0} for node = "IMAGE_0"
2 Answers:
I'm not sure it's possible the way you described - Parameters in JRS are like variables in Java - they are defined at the beginning of report processing and Fields are not available until after the Report is processed and a result (from the dataset/query) is obtained. So you can't change the names of Parameters after it's run the report. However you CAN pass your Field values to a subreport AS a Parameter in that subreport. Wouldn't that accomplish what you want?
