I am struggling to select a property from a JSON array that I've stored in a variable (as an array). I receive the following error:
The execution of template action 'Select' failed: The evaluation of 'query' action >'where' expression '{
"Response": "#variables('UserEvents').responseStatus.response",
"trest": ""
}' failed: 'The template language expression >'variables('UserEvents').responseStatus.response' cannot be evaluated because property >'responseStatus' cannot be selected. Array elements can only be selected using an > integer index. Please see https://aka.ms/logicexpressions for usage details.'.
The JSON is below:
[
{
"value": [
{
"responseStatus": {
"response": "notResponded",
"time": "0001-01-01T00:00:00Z"
}
}
]
}
]
I'm trying to select the 'response' property only by using the following expression:
#variables('UserEvents').responseStatus.response
I have tried adding [0] to various parts of the above expression but it doesn't seem to make any difference. I am sure it's pretty simple and I'm just getting the syntax wrong, but am completely stuck!
Any help appreciated - thanks.
Adrian
#{
variables('UserEvents') ? ['value'] ? [0] ? ['response']
}
Try that. The integer index mentioned in the error is the way around this. May need to play around with the structure to make it match your data but [0] will make it select the first object within your value array.
There are 2 ways to get the properties inside a nested JSON
WAY - 1 (Try to get properties using For-each loop)
For this we need to use 2 for-each loops to retrieve the property inside the nested JSON After Parsing the JSON. Below is the screenshot of my logic app for your reference.
WAY - 2 (Using Dynamic Expression)
Here is the Expression that worked for me.
body('Parse_JSON')?[0]?['value']?[0]?['responseStatus']?['response']
Since it is in Array of Array format we need to mention the index of the array. Below is the screenshot of my logic app for your reference :
output :
Related
My aim is to use Azure Data Factory to copy data from one place to another using REST API.
The first part of the copying is using the ForEach activity to select parameters from a nested JSON/array. I have had problems with this nested JSON because of various error messages in the ForEach activity.
My JSON is of the following form:
(
{
"key_1": "value_1",
"key_2": [
"value_2_1",
"value_2_2"
]
}
)
and first I'm setting the #json conversion function in front of it:
#json(
'{
"key_1": "value_1",
"key_2": [
"value_2_1",
"value_2_2"
]
}'
)
Here you can see the Execute Pipeline object and its parameters:
I am setting this JSON as a parameter in the Execute Pipeline object. I am setting its type as an "Array". (For the record, I have still had similar error messages even though I have tried to change the parameter type to "String" or "Object".)
The ForEach activity is used to select an item from the nested JSON, which is written into a parameter.
This immediately produces the following error in the Execute Pipeline activity:
Operation on target... ...failed: The function 'length' expects its parameter to be an array or a string. The provided value is of type 'Object'.
So, even though I set the JSON parameter type to "Array", it is changed into "Object" when I debug the pipeline activity. See the error below:
Next, I tried to use the ADF #createArray function before my JSON text.
#createArray(
'{
"key_1": "value_1",
"key_2": [
"value_2_1",
"value_2_2"
]
}'
)
When debugging, the forEach activity throws me an error in the first Copy data activity:
The expression 'concat(item().SELECTING_key_1_FROM_MY_JSON))' cannot be evaluated because property 'key_1' cannot be selected. Property selection is not supported on values of type 'String'.
Please help me, what I am doing wrong in my attempts of converting the JSON to an array? What should I change in my code?
So far I have tried changing the parameter type and using various functions in the JSON dynamic content but with no luck.
update:
If you want change the filename in Copy Data --> Sink.
You can key in the dynamic content #concat(pipeline().parameters.Pip_Object.key_1,'.json') to rename the file.
Please correct me if I understand you wrong.
First, we should use Parameters to store the Json array as follows. Because Variables are not support to store the Json array. Variables are only support to store simple data type such as ["1","2","3"...].
Json array format should as follows:
[{"key_1": "value_1"},{"key_2": ["value_2_1","value_2_2"]}]
I created a simple test here. Then ForEach the Json array:
Inside ForEach1 activity, pass #item() to the object type parameter Pip_Object.
The Input is as follows:
Add dynamic content above using any combination of expressions, functions and system variables at for each settings
#activity('Get Metadata1').output.childItems
We ended up using two pipelines: a generic one and a specific one.
The generic one has the JSON as a parameter (JSON_PARAMETER), and we set it a default value in the following form
[{"key_1":"value_1","key_2":["value_2"]},{"key_1":"value_3","key_2":["value_2"]}, ...etc. ...}]
The generic pipeline has a forEach loop, in which that mentioned JSON parameter is called in Settings -> Items:
#JSON(pipeline().parameters.JSON_PARAMETER)
In the specific pipeline, there is an Execute Pipeline activity, where the JSON_PARAMETER is found in Settings -> Parameters. If the default value of JSON_PARAMETER is used, the field is left blank. If we want to change the parameter, before Execute Pipeline, we put a Set Variable activity where we change the Variables -> Value to:
#concat('
[
{"key_1":"value_1",
"key_2":
["value_2",
"value_3"
]
},
{"key_1":"value_3",
...and so on...
}
]
')
I'm making API requests to a service which returns a JSON object within the body.
I can't seem to get the value of a key called "properties" within groovy.
Everytime I call obj.properties i get the following back
{
"class": "org.json.JSONObject"
}
but if I call just the obj I get the expected JSON object
{
"dummy1": ,
"dummy2": false,
"dummy3": etsad,
"dummy4": asdfw,
"dummy5": qweqwe,
"dummy6": 123123,
"properties": {
"country": UK,
}
}
Likewise if I obj.dummy2 i get false it's only when I obj.properties do I get the above mentioned response
Notice groovy have a special handling for Object's properties, for example for number:
def y = 25
print y.properties
It will print [class:class java.lang.Integer]
So it's part of basic groovy object
See also an answer about getting non-synthetic properties from groovy object
As #daggett comment, you can use
obj.get('properties')
Check out this answer here on how to access the properties of objects.
The reason obj.properties isn't working is most likely due to the fact that every object will have properties, and in your case obj.properties is getting the properties of the JSON object and not the value associated with the key.
Instead of obj.properties, consider obj['properties']
I have a json which I am reading in R and converting to a list object. For a key "metrics", there is an array of multiple objects of the same type.
Json structure:
{"metrics":[{"metricName":"abc",
"metricType":"def"
},
{"metricName":"ghi",
"metricType":"jkl"
}]
}
This is how my list object looks like:
$metrics
$metrics[[1]]
$metrics[[1]]$metricName
[1] "abc"
$metrics[[1]]$metricType
[1] "def"
$metrics[[2]]
$metrics[[2]]$metricName
[1] "ghi"
$metrics[[2]]$metricType
[1] "jkl"
I want to apply a function (someFunc) to each object of the array. $metrics[[1]],$metrics[[2]]. How can this be done using apply family of functions?
somefunc(x){return(list(x$metricName,x$metricType)}
I tried concatenating like this:
lapply(lapply(metrics,"["),someFunc)
This does not throw an error but gives empty lists as output. The someFunc expects x$metricName,x$metricType objects to process. But using "[" does not render that kind of object I guess. Can this be handled using the apply functions?
Can you explici what your function someFunc is doing (and its parameters)?
This is working for me
someFunc=function(metricName,metricType){
return(paste(metricName,metricType))
}
metrics=list(list(metricName="abc",metricType="m"),
list(metricName="gg",metricType="L"))
lapply(metrics,FUN=function(el){someFunc(el$metricName,el$metricType)})
(use sapply eventually if you want to have a vector.
[
{
"type": "spline",
"name": "W dor\u0119czeniu",
"color": "rgba(128,179,236,1)",
"mystring": 599,
"data": ...
}
]
I am trying to access this json as json['W doręczeniu']['mysting'], and I get no value why is that?
You're trying to access the index "W doręczeniu" but that's not an index it's a value. Also, what you seem to have is an array of JSON objects.
The [ at the start marks the array, the first element of which is your JSON object. The JSON obj begins with the {
You're also trying to use a [ ], but JSON values are accessed with the dot operator.
I'm not sure which index you're actually trying to access, but try something like this:
var x = json[0].mystring;
The value of "W doręczeniu" is not a key, so you cannot use it to get a value. Since your json string is an array you'll have to do json[0].nameto access the first (and only) element in the array, which happens to be the object. Of course, this is assuming json is the variable you store the array into.
var json = [{"type":"spline","name":"W dor\u0119czeniu","color":"rgba(128,179,236,1)","mystring":599}];
console.log(json[0].mystring); //should give you what you want.
EDIT:
To get the last element in a js array, you can simply do this:
console.log( json[json.length -1].mystring ); // same output as the previous example
'length - 1' because js arrays are indexed at 0. There's probably a million and one ways to dynamically get the array element you want, which are out of the scope of this question.
I have the following JSON and I need to get the plain name value using JSONPath:
{
"single" : {
"id" : 1,
"name" : "Item name"
}
}
Expression that I used is $.single.name but I always get an array:
[ "Item name" ]
instead of a string value ("Item name").
but I always get an array:
That is meant to happen. As you can read in this documentation, under 'Result' (almost at the bottom):
Please note, that the return value of jsonPath is an array, which is
also a valid JSON structure. So you might want to apply jsonPath to
the resulting structure again or use one of your favorite array
methods as sort with it.
So basically it will always return an array. If you need the data as an other type, e.g. a String in this case, you will have to do the conversion yourself I'm afraid.
I was using the Java implementation of JSONPath and got to the very same issue. What worked for me was to add '[0]' to the json path string. So in your case:
$.single.name[0]
I think, it depends of language implementation.
For example in nodejs there is a npm module : https://www.npmjs.com/package/jsonpath
Which have a method called value, which does exactly what we need
jp.value(obj, pathExpression[, newValue])
Returns the value of the first element matching pathExpression. If newValue is provided, sets the value of the first matching element and returns the new value.
I tried it and worked!
In case you got this error
"Unable to get a scalar value for expression $.yourfield"
You have just to configure the EvaluateJsonPath processor by changing the return type property value to 'json' instead of 'auto-detect'