I'm getting a JSON string from a curl request, like this:
[
{
"name": "P309",
"path": "P309",
"sha": "b9dbfa7ceb9db3b73c84ff326a418bdd50c1b227",
"type": "file",
"_links": {
"self": "https://api.github.com/repos//files/contents/P309?ref=main",
"git": "https://api.github.com/repos//files/git/blobs/b9dbfdd50c1b227",
"html": "https://github.com//files/blob/main/P309"
}
},
{
"name": "P310",
"path": "P310",
"sha": "b9dbfa7ceb9db3b73c84ff326a418bdd50c1b227",
"_links": {
"self": "https://api.github.com/repos//files/contents/P309?ref=main",
"git": "https://api.github.com/repos//files/git/blobs/b9dbfdd50c1b227",
"html": "https://github.com//files/blob/main/P309"
}
},
]
How can I parse/read it using the nlohmann::json lib?
I've found this example:
/*
"emulators": [
{
"general_info": {
"dev_id": "0123456789"
}
}
]
*/
for(json& o : data["emulators"]) {
json& gi = o["general_info"];
std::cout << gi["dev_id"] << '\n';
}
My JSON being parsed doesn't have any 'title/header', I'm confused about how to read it.
I tried:
using json = nlohmann::json;
json data = json::parse(downloaded_data);
for(json& o : data[0]) {
auto git = o["git"].get<std::string>();
auto name = o["name"].get<std::string>();
}
git outputs the value correctly, however, when reading name it throws an exception.
This is the value of data in the debugger
and this, of o.
Can I get any help on this?
Related
my resolver in schema.py looks like this
def resolve_areas(self, info, **kwargs):
result = []
dupfree = []
user = info.context.user
areas = BoxModel.objects.filter(client=user, active=True).values_list('area_string', flat=True)
In GraphiQL I am using this query:
{
areas {
edges {
node {
id
name
}
}
}
}
And get Output that starts like this:
{
"data": {
"areas": {
"edges": [
{
"node": {
"id": "QXJlYTpkZWZ",
"name": "default"
}
},
{
"node": {
"id": "QXJlYTptZXN",
"name": "messe"
}
},
{
"node": {
"id": "QXJlYTptZXN",
"name": "messe"
}
},
But i want distinct values on the name variable
(Using a MySQL Database so distinct does not work)
SOLVED:
distinct was not working. so i just wrote a short loop which tracked onlye the string names duplicates in a list and only appended the whole "area" object if it's name has not been added to the duplicates list yet
result = []
dupl_counter = []
for area in areas:
if area not in dupl_counter:
dupl_counter.append(area)
result.append(Area(name=area))
print(area)
I am ok using this syntax with the nlohmann library
{
"key1": {"subKey1": "value11",
"subKey2": "value12"},
"key2": {"subKey1": "value21",
"subKey2": "value22"}
}
But I have a new file, which is valid json too (I checked) and is written this way, it is made of a single array of repetitive objects. My code will require to look through those objects and check values inside them individually:
[
{"key1": "value11",
"key2": "value12"},
{"key1": "value21",
"key2": "value22"}
]
I used to read my json files this way:
#include "json.hpp"
nlohmann::json topJson;
nlohmann::json subJson;
if(topJson.find(to_string("key1")) != topJson.end())
{
subJson = topJson["key1"];
entity.SetSubKeyOne(subJson["subKey1"]);
}
But this won't work with my new file syntax. How can I access these repetitive objects and tell nlohmann that my objects are inside an array? More precisely, how would I be able to reach (for example) "value22" with this file syntax?
Thanks!
You can try this:
std::string ss= R"(
{
"test-data":
[
{
"name": "tom",
"age": 11
},
{
"name": "jane",
"age": 12
}
]
}
)";
json myjson = json::parse(ss);
auto &students = myjson["test-data"];
for(auto &student : students) {
cout << "name=" << student["name"].get<std::string>() << endl;
}
I have a below json data. I am using nlohmann json in C++.
{
"CompanyName": "XYZ Tech",
"Created": "2019-10-16T20:14:29Z",
"TxnId": "4509237",
"Tags": [
{
"ROIId": "Default",
"Time": 71,
"Tracker": "emp10"
},
{
"ROIId": "MC16",
"Time": 21,
"TrackerId": "emp10"
},
{
"ROIId": "Default",
"Time": 11,
"TrackerId": "emp11"
},
{
"ROIId": "MC18",
"Time": 10,
"TrackerId": "emp11"
}
],
"Type": "TxnData"
}
In above json data, inside Tags, we have data where the ROIId is Default. I want to delete it so that the data becomes:
{
"CompanyName": "XYZ Tech",
"Created": "2019-10-16T20:14:29Z",
"TxnId": "4509237",
"Tags": [
{
"ROIId": "MC16",
"Time": 21,
"TrackerId": "emp10"
},
{
"ROIId": "MC18",
"Time": 10,
"TrackerId": "emp11"
}
],
"Type": "TxnData"
}
How can I do it in c++. Thanks
I suggest iterating through the json::array stored in Tags and saving the Key of the matched elements. This way you can later validate the deletion and safely delete the elements.
Note that deleting is exactly like erasing with a STL vector - I prefer to delete from the end of the vector to avoid changing the keys while deleting multiple elements.
Here is a quick and dirty demo
And here is the code:
#include <iostream>
#include <vector>
#include "json3.6.1.hpp"
unsigned removeDefaultROIID(nlohmann::json& jsonObject, const std::string& value) {
std::vector<int> toremove;
//Loop through the `tags` json::array and create a vector of indexes to delete:
for (auto &it : jsonObject["Tags"].items()) {
//`.get<std::string>()` is the best way to make sure we are getting the value as std::string
if (it.value().at("ROIId").get<std::string>() == value)
toremove.push_back(stoi(it.key()));
}
//sort it before erase - we want to delete first biggest index:
std::sort(toremove.rbegin(), toremove.rend());
//delete using `.erase()` method:
for (int &it : toremove)
jsonObject["Tags"].erase(jsonObject["Tags"].begin() + it);
return toremove.size();
}
int main()
{
//Create the JSON object:
nlohmann::json jsonObject = R"({"CompanyName":"XYZ Tech","Created":"2019-10-16T20:14:29Z","TxnId":"4509237","Tags":[{"ROIId": "Default","Time": 71,"Tracker": "emp10"},{"ROIId":"MC16","Time": 21,"TrackerId": "emp10"},{"ROIId":"Default","Time":11,"TrackerId":"emp11"},{"ROIId":"MC18","Time": 10,"TrackerId":"emp11"}],"Type":"TxnData"})"_json;
std::cout << "JSON nested object value conditional erase:" << std::endl;
std::cout << "JSON object TAGS count - BEFORE deletion:" << jsonObject["Tags"].size() << std::endl;
//Call the method -> jlson is passed by ref
unsigned removed = removeDefaultROIID(jsonObject, "Default");
std::cout << "JSON object TAGS count - AFTER deletion:" << jsonObject["Tags"].size() << std::endl;
return 0;
}
I am using nlohmann json to create ans save some json values. But when I look at the file, I get null values in between the json. Below is how it looks like:
{
"Created": "2019-07-03T13:54:32Z",
"DataId": "BHI-201-U8",
"Data": [
{
"Name": "Andrew",
"Attended": "Yes"
},
{
"Name": "John",
"Attended": "Yes"
},
null, <-- unexpected null
{
"Name": "Ronny",
"Attended": "No"
},
null, <-- unexpected null
null, <-- unexpected null
{
"Name": "Mathew",
"Attended": "Yes"
}
],
"Type": "Person"
}
As you can see in the above json data, I am getting some unexpected null. Below is how I am saving it:
#include "nlohmann/json.hpp"
using nlohmann::json;
int main()
{
json outJson;
//some code
string outFile = "output.json";
for (const auto &data : trackedData->Detections())
{
//some code
outJson["Data"][data.id]["Name"] = data.name;
outJson["Data"][data.id]["Attended"] = data.status;
}
outJson["Created"] = created;
outJson["DataId"] = "BHI-201-U8";
outJson["Type"] = "Person";
std::ofstream output_file(outFile);
output_file << outJson.dump(4 , ' ', false);
output_file.close();
}
How can I remove these extra null from the code.
trackedData->Detections() returns a list of objects or structures and some of them are null-valued, hence nulls in the json. Try to do null-checking before adding data entry into json.
for (const auto &data : trackedData->Detections())
{
//some code
if (data != NULL)
{
outJson["Data"][data.id]["Name"] = data.name;
outJson["Data"][data.id]["Attended"] = data.status;
}
}
I'm using gatsby to create a simple blog. When I try to search for an specific image, I get an error from graphql. I have the following configs:
installed "gatsby-image": "^1.0.55"
graphql`
query MainLayoutQuery {
heroImage: imageSharp(id: { regex: "/hero.jpg/" }) {
id
sizes(quality: 100) {
base64
tracedSVG
aspectRatio
src
srcSet
srcWebp
srcSetWebp
sizes
originalImg
originalName
}
}
}
`
when I run that query in graphql ui I get:
{
"errors": [
{
"message": "Cannot read property 'id' of undefined",
"locations": [
{
"line": 31,
"column": 3
}
],
"path": [
"heroImage"
]
}
],
"data": {
"heroImage": null
}
}
But, if I run the same query without the regex, it works fine:
{
heroImage: imageSharp {
id
sizes(quality: 100) {
base64
tracedSVG
aspectRatio
src
srcSet
srcWebp
srcSetWebp
sizes
originalImg
originalName
}
}
}
Of course, it brings the first image it has access to
"data": {
"heroImage": {
"id": "/Users/marcosrios/dev/workspace/atravesando-todo-limite/src/posts/2018-08-25-tengo-miedo/cover.png absPath of file >> ImageSharp"
}
}
Which version of Gatsby are you using? If v2 you need to edit your query as there has been changes:
https://next.gatsbyjs.org/docs/migrating-from-v1-to-v2/#dont-query-nodes-by-id
Your query then would look like that:
graphql`
query MainLayoutQuery {
heroImage: imageSharp(fluid: { originalName: { regex: "/hero.jpg/" } }) {
id
fluid(quality: 100) {
base64
tracedSVG
aspectRatio
src
srcSet
srcWebp
srcSetWebp
sizes
originalImg
originalName
}
}
}
`