Django combine two json objects to form a new array - json

Question

I have two json objects as follow
Id:1
{"points":[{"x":109,"y":286,"r":1,"color":"black"},{"x":108,"y":285,"r":1,"color":"black"},{"x":106,"y":282,"r":1,"color":"black"},{"x":103,"y":276,"r":1,"color":"black"},],"lines":[{"x1":109,"y1":286,"x2":108,"y2":285,"strokeWidth":"2","strokeColor":"black"},{"x1":108,"y1":285,"x2":106,"y2":282,"strokeWidth":"2","strokeColor":"black"},{"x1":106,"y1":282,"x2":103,"y2":276,"strokeWidth":"2","strokeColor":"black"}]}
Id-2
{"points":[{"x":524,"y":343,"r":1,"color":"black"},{"x":523,"y":342,"r":1,"color":"black"},{"x":521,"y":339,"r":1,"color":"black"},{"x":520,"y":334,"r":1,"color":"black"},{"x":514,"y":319,"r":1,"color":"black"}],"lines":[{"x1":524,"y1":343,"x2":523,"y2":342,"strokeWidth":"2","strokeColor":"black"},{"x1":523,"y1":342,"x2":521,"y2":339,"strokeWidth":"2","strokeColor":"black"},{"x1":521,"y1":339,"x2":520,"y2":334,"strokeWidth":"2","strokeColor":"black"},{"x1":520,"y1":334,"x2":514,"y2":319,"strokeWidth":"2","strokeColor":"black"}]}
I am trying to merge these two data onto a canvas
I am able to retrieve a single file but combining them i am not able to do
def loadDrawing(request):
""" Function to load the drawing with drawingID if it exists."""
try:
# Getting JSON object string of saved drawing.
drawingJSONData = Drawing.objects.get(id = 1).drawingJSONText
# drawingJSONData1 = Drawing.objects.get(id=1).drawingJSONText
# drawingJSONData2 = Drawing.objects.get(id=2).drawingJSONText
# Seding context with appropriate information
context = {
"loadIntoJavascript" : True,
"JSONData" : drawingJSONData
}
# Editing response headers and returning the same
response = modifiedResponseHeaders(render(request, 'MainCanvas/index.html', context))
return response
My model in django
class Drawing(models.Model):
drawingJSONText = models.TextField(null = True)
My .js file to load the drawing and parsing it from server to JSON object and pushing the loaded points into an array
// Checking if the drawing to be loaded exists
if (document.getElementById('JSONLoadData') != null)
{
// Parsing the loaded drawing from server to a JSON Object
var loadedData = JSON.parse(JSONLoadData.value)
// Iterating through all the points in the loaded drawing
for(let i = 0; i < loadedData['points'].length; i++)
{
// Saving the point and drawing the same in the svg canvas
const point = svg.append('circle')
.attr('cx', loadedData['points'][i]['x'])
.attr('cy', loadedData['points'][i]['y'])
.attr('r', loadedData['points'][i]['r'])
.style('fill', loadedData['points'][i]['color']);
// Pushing the point inside points array
points.push(point);
}
// Iterating through all the lines in the loaded drawing
for(let i = 0; i < loadedData['lines'].length; i++)
{
// Saving the line and drawing the same in the svg canvas
const line = svg.append('line')
.attr('x1', loadedData['lines'][i]['x1'])
.attr('y1', loadedData['lines'][i]['y1'])
.attr('x2', loadedData['lines'][i]['x2'])
.attr('y2', loadedData['lines'][i]['y2'])
.attr('stroke-width', loadedData['lines'][i]['strokeWidth'])
.style('stroke', loadedData['lines'][i]['strokeColor']);
// Pushing the line inside lines array
lines.push(line);
}
}
});
Edited :
If my model is as follows
class Drawing(models.Model):
drawingJSONText = models.TextField(null=True)
project = models.CharField(max_length=250)
How can i filter data based on project
Lets say i have three datasets
1st one contains project = a
2nd one contains project = b
3rd one contains project = a
4th one contains project = a
How can i add datapoints like above by filtering data Drawing.objects.filter(project=a)
then based on the queryset i have three data points and corresponding data are plotted on canvas as above

Answer 1

I'm not entirely sure this is what you want, but are you trying to combine id-1 and id-2? If I think I understand what you are trying to do, will using the + operator work for you in this case?
drawingJSONData1 = json.loads(Drawing.objects.get(id=1).drawingJSONText)
drawingJSONData2 = json.loads(Drawing.objects.get(id=1).drawingJSONText)
drawingJSONData = dict()
drawingJSONData["points"] = drawingJSONData1["points"]+drawingJSONData1["points"]
drawingJSONData["lines"] = drawingJSONData2["lines"]+drawingJSONData2["lines"]
With your example above, you'd end up with:
{'points': [{'x': 109, 'y': 286, 'r': 1, 'color': 'black'},
{'x': 108, 'y': 285, 'r': 1, 'color': 'black'},
{'x': 106, 'y': 282, 'r': 1, 'color': 'black'},
{'x': 103, 'y': 276, 'r': 1, 'color': 'black'},
{'x': 524, 'y': 343, 'r': 1, 'color': 'black'},
{'x': 523, 'y': 342, 'r': 1, 'color': 'black'},
{'x': 521, 'y': 339, 'r': 1, 'color': 'black'},
{'x': 520, 'y': 334, 'r': 1, 'color': 'black'},
{'x': 514, 'y': 319, 'r': 1, 'color': 'black'}],
'lines': [{'x1': 109,
'y1': 286,
'x2': 108,
'y2': 285,
'strokeWidth': '2',
'strokeColor': 'black'},
{'x1': 108,
'y1': 285,
'x2': 106,
'y2': 282,
'strokeWidth': '2',
'strokeColor': 'black'},
{'x1': 106,
'y1': 282,
'x2': 103,
'y2': 276,
'strokeWidth': '2',
'strokeColor': 'black'},
{'x1': 524,
'y1': 343,
'x2': 523,
'y2': 342,
'strokeWidth': '2',
'strokeColor': 'black'},
{'x1': 523,
'y1': 342,
'x2': 521,
'y2': 339,
'strokeWidth': '2',
'strokeColor': 'black'},
{'x1': 521,
'y1': 339,
'x2': 520,
'y2': 334,
'strokeWidth': '2',
'strokeColor': 'black'},
{'x1': 520,
'y1': 334,
'x2': 514,
'y2': 319,
'strokeWidth': '2',
'strokeColor': 'black'}]}
EDIT: added the gets wrapped in json.loads to convert string to Python object as I don't know what kind of field that is and given the error being seen.