I have been trying to output a yaml file using YAML::Emitter. For instance, I need something like this to be my yaml file.
annotations:
- run:
type: range based
attributes:
start_frame:
frame_number: 25
end_frame:
frame_number: 39
So far, using my code
for (auto element : obj)
{
basenode = YAML::LoadFile(filePath); //loading a file throws exception when it is not a valid yaml file
//Check if metadata is already there
if (!basenode["file_reference"])
{
writeMetaData(element.getGttStream(), element.getTotalFrames(), element.getFileHash());
}
annotationNode["annotations"].push_back(element.getGestureName());
annotationNode["type"] = "range based";
output << annotationNode;
attributesNode["attributes"]["start_frame"]["frame_number"] = element.getStartFrame();
attributesNode["attributes"]["end_frame"]["frame_number"] = element.getEndFrame();
output << typeNode;
output << attributesNode;
ofs.open(filePath, std::ios_base::app);
ofs << std::endl << output.c_str();
}
I am getting an output like this
annotations:
- run
type: range based
---
attributes:
start_frame:
frame_number: 26
end_frame:
frame_number: 57
I want the "type" and "attributes" under the recently pushed sequence item into the "annotations" and subsequently the same for all the following nodes.
I even tried using something like this
annotationNode[0][type] = "range based"
and the output was like this
0: type: "range based"
How do i get the recently pushed item in the sequence "annotations"?
If you're building up your root node, annotationNode, then just build it up and output it once. You wouldn't need to write either the typeNode or attributesNode to the emitter. For example, you might write
YAML::Node annotationNode;
for (auto element : obj) {
YAML::Node annotations;
annotations["name"] = element.getGestureName();
annotations["type"] = ...;
annotations["attributes"] = ...;
annotationNode["annotations"] = annotations;
}
output << annotationNode;
Related
I'm learning Avro & C++ (both together :) ) and what i'm trying to do is:
Load a schema.
Map the schema fields to key / value paris of name & type.
Then iterate the avro data according to the mapping.
From what I've found and did, I'm extracting the schema from the Avro data file, and handles it as GenricDatum.
When I try to iterate it's fields - I get the name ok, but the field type is null, where I would expect to get the actual type. any help would be appreciated.
My code:
const char *avroFilePathCstr = avroFilePath.c_str();
avro::DataFileReader<avro::GenericDatum> reader(avroFilePathCstr);
auto dataSchema = reader.dataSchema();
avro::GenericDatum datum(dataSchema);
ProcessAvroSchema(dataSchema);
void ProcessAvroSchema(avro::GenericDatum schema) {
const avro::GenericRecord& schemaRecord = schema.value<avro::GenericRecord>();
for(unsigned int i = 0 ; i < schemaRecord.fieldCount(); i++)
{
avro::GenericDatum fieldDatum = schemaRecord.fieldAt(i);
cout << "SCHEMA:: fieldName: " << schemaRecord.schema() -> nameAt(i) << " , fieldType: " << fieldDatum.type() << "\n";
}
}
I'm new to xml, and using the pugixml documentation I haven't been able to read a node attribute to the console. The core of the issue is that I don't understand how the node accessing structure works and I haven't been able to figure it out using my code.
The code provided is a lightly modified line from the actual pugixml manual, so I'm not sure why it isn't working.
XML FILE LOADED
<?xml version="1.0" encoding="utf-8"?>
<settings description="settings root description">
<!--settings for the options menu-->
<options description="game options">
<resolution description="resolution in 16:9 ratio">6</resolution>
<volume description="volume setting">0</volume>
</options>
</settings>
C++ CODE TRYING TO USE XML FILE
//set up and load settings xml doc
pugi::xml_document settingsXML;
pugi::xml_parse_result settingsResult = settingsXML.load_file("SFMLVania/include/Settings.xml");
std::cout << "Root description: " << settingsXML.root().attribute("description").as_string();
I'm expecting to see:
"Root description: settings root description"
in the console.
Instead, I'm getting:
"Root description: "
SECOND ATTEMPT -- to try and just get any data and find out where I am in the tree:
std::cout << "Second attempt: " << settingsXML.first_attribute().as_string();
All I got from the second attempt was the console spitting out: "Second attempt: "
It turns out, my load path didn't exist, I had forgotten to use ../ to go up a directory and out of the Debug folder where the .exe was stored. I figured this out by testing the load result that could be passed as a bool.
if (settingsResult)
{
std::cout << "returned true\n";
}
else
std::cout << "returned false\n";
if (!settingsResult)
{
std::cout << "also returned false\n";
}
I included some redundant returns in case the bool value didn't function as expected.
The result showed that there was no file loaded (it returned false), and when I reexamined my file structure and added the ../ as a test to the file path, it returned true.
For anyone that comes across this, you can prevent this error by adding a minimal parse check after the assigning of settingsResult like this:
pugi::xml_document settingsXML;
pugi::xml_parse_result settingsResult = settingsXML.load_file("SFMLVania/include/Settings.xml");
// Catch parsing error
if (!settingsResult )
{
std::cout << "ERROR: " << settingsResult.description() << '\n';
return -1;
}
This will catch a bad parse and log the error to the console.
I am developing a quick DICOM viewer using DCMTK library and I am following the example provided in this link.
The buffer from the API always returns null for any tag ID, eg: DCM_PatientName.
But the findAndGetOFString() API works fine but returns only the first character of the tag in ASCII, is this how this API should work?
Can someone let me know why the buffer is empty the former API?
Also the DicomImage API also the same issue.
Snippet 1:
DcmFileFormat fileformat;
OFCondition status = fileformat.loadFile(test_data_file_path.toStdString().c_str());
if (status.good())
{
OFString patientName;
char* name;
if (fileformat.getDataset()->findAndGetOFString(DCM_PatientName, patientName).good())
{
name = new char[patientName.length()];
strcpy(name, patientName.c_str());
}
else
{
qDebug() << "Error: cannot access Patient's Name!";
}
}
else
{
qDebug() << "Error: cannot read DICOM file (" << status.text() << ")";
}
In the above snippet name has the ASCII value "50" and the actual name is "PATIENT".
Snippet 2:
DcmFileFormat file_format;
OFCondition status = file_format.loadFile(test_data_file_path.toStdString().c_str());
std::shared_ptr<DcmDataset> dataset(file_format.getDataset());
qDebug() << "\nInformation extracted from DICOM file: \n";
const char* buffer = nullptr;
DcmTagKey key = DCM_PatientName;
dataset->findAndGetString(key,buffer);
std::string tag_value = buffer;
qDebug() << "Patient name: " << tag_value.c_str();
In the above snippet, the buffer is null. It doesn't read the name.
NOTE:
This is only a sample. I am just playing around the APIs for learning
purpose.
The following sample method reads the patient name from a DcmDataset object:
std::string getPatientName(DcmDataset& dataset)
{
// Get the tag's value in ofstring
OFString ofstring;
OFCondition condition = dataset.findAndGetOFString(DCM_PatientName, ofstring);
if(condition.good())
{
// Tag found. Put it in a std::string and return it
return std::string(ofstring.c_str());
}
// Tag not found
return ""; // or throw if you need the tag
}
I have tried your code with your datasets. I just replaced the output to QT console classes to std::cout. It works for me - i.e. it prints the correct patient name (e.g. "PATIENT2" for scan2.dcm). Everything seems correct, except for the fact that you apparently want to transfer the ownership for the dataset to a smart pointer.
To obtain the ownership for the DcmDataset from the DcmFileFormat, you must call getAndRemoveDataset() instead of getDataset(). However, I do not think that your issue is related that. You may want to try my modified snippet:
DcmFileFormat file_format;
OFCondition status = file_format.loadFile("d:\\temp\\StackOverflow\\scan2.dcm");
std::shared_ptr<DcmDataset> dataset(file_format.getAndRemoveDataset());
std::cout << "\nInformation extracted from DICOM file: \n";
const char* buffer = nullptr;
DcmTagKey key = DCM_PatientName;
dataset->findAndGetString(key, buffer);
std::string tag_value = buffer;
std::cout << "Patient name: " << tag_value.c_str();
It probably helps you to know that your code and the dcmtk methods you use are correct, but that does not solve your problem. Another thing I would recommend is to verify the result returned by file_format.loadFile(). Maybe there is a surprise in there.
Not sure if I can help you more, but my next step would be to verify your build environment, e.g. the options that you use for building dcmtk. Are you using CMake to build dcmtk?
I am using jsonc-libjson to create a json string like below.
{ "author-details": {
"name" : "Joys of Programming",
"Number of Posts" : 10
}
}
My code looks like below
json_object *jobj = json_object_new_object();
json_object *jStr1 = json_object_new_string("Joys of Programming");
json_object *jstr2 = json_object_new_int("10");
json_object_object_add(jobj,"name", jStr1 );
json_object_object_add(jobj,"Number of Posts", jstr2 );
this gives me json string
{
"name" : "Joys of Programming",
"Number of Posts" : 10
}
How do I add the top part associated with author details?
To paraphrase an old advertisement, "libjson users would rather fight than switch."
At least I assume you must like fighting with the library. Using nlohmann's JSON library, you could use code like this:
nlohmann::json j {
{ "author-details", {
{ "name", "Joys of Programming" },
{ "Number of Posts", 10 }
}
}
};
At least to me, this seems somewhat simpler and more readable.
Parsing is about equally straightforward. For example, let's assume we had a file named somefile.json that contained the JSON data shown above. To read and parse it, we could do something like this:
nlohmann::json j;
std::ifstream in("somefile.json");
in >> j; // Read the file and parse it into a json object
// Let's start by retrieving and printing the name.
std::cout << j["author-details"]["name"];
Or, let's assume we found a post, so we want to increment the count of posts. This is one place that things get...less tasteful--we can't increment the value as directly as we'd like; we have to obtain the value, add one, then assign the result (like we would in lesser languages that lack ++):
j["author-details"]["Number of Posts"] = j["author-details"]["Number of Posts"] + 1;
Then we want to write out the result. If we want it "dense" (e.g., we're going to transmit it over a network for some other machine to read it) we can just use <<:
somestream << j;
On the other hand, we might want to pretty-print it so a person can read it more easily. The library respects the width we set with setw, so to have it print out indented with 4-column tab stops, we can do:
somestream << std::setw(4) << j;
Create a new JSON object and add the one you already created as a child.
Just insert code like this after what you've already written:
json_object* root = json_object_new_object();
json_object_object_add(root, "author-details", jobj); // This is the same "jobj" as original code snippet.
Based on the comment from Dominic, I was able to figure out the correct answer.
json_object *jobj = json_object_new_object();
json_object* root = json_object_new_object();
json_object_object_add(jobj, "author-details", root);
json_object *jStr1 = json_object_new_string("Joys of Programming");
json_object *jstr2 = json_object_new_int(10);
json_object_object_add(root,"name", jStr1 );
json_object_object_add(root,"Number of Posts", jstr2 );
I'm using the mongocxx driver and I am considering keeping the query results given in BSON as a data holder in a couple of objects instead of parsing the BSON to retrieve the values and then discard it.
This would make some sense "if" I can edit the BSON on the fly. I couldn't find anything in the bsoncxx driver documentation besides the builder that would allow me to manipulate a bsoncxx document/value/view/element after it's been constructed.
As an example, imagine that I have something like this
fruit["orange"];
where fruit is a bsoncxx::document::element
I can get the value by using one of the .get_xxx operators.
What I can't find is something like
fruit["orange"] = "ripe";
Is there a way of doing this, or the idea behind the builder is "just" to create a query to give to the database?
There was a question with same theme, see here
So, bsoncxx objects seem to be immutable, and we have to re-create them if we need to edit them.. :(
I've written a really bad solution which re-creates document from scratch
But this is a solution, I guess.
std::string bsoncxx_string_viewToString(core::v1::string_view gotStringView) {
std::stringstream convertingStream;
convertingStream << gotStringView;
return std::move(convertingStream.str());
}
std::string b_utf8ToString(bsoncxx::types::b_utf8 gotB_utf8) {
return std::move(bsoncxx_string_viewToString(core::v1::string_view(gotB_utf8)));
}
template <typename T>
bsoncxx::document::value editBsoncxx(bsoncxx::document::view documentToEdit, std::string keyToEdit, T newValue, bool appendValueIfKeyNotExist = true) {
auto doc = bsoncxx::builder::stream::document{};
std::string currentKey;
for (auto i : documentToEdit) {
currentKey = bsoncxx_string_viewToString(i.key());
if (currentKey == keyToEdit) {
doc << keyToEdit << newValue;
appendValueIfKeyNotExist = false;
} else {
doc << currentKey << i.get_value();
}
}
if (appendValueIfKeyNotExist) // Maybe this would be better with documentToEdit.find(key), but I don't know how to check if iterator is past-the-end
//If there is a way to check if bsoncxx contains key, we can achieve ~o(log(n)) [depending on 'find key' implementation] which is better than o(n)
doc << keyToEdit << newValue;
return doc.extract();
}
Usage:
auto doc = document{} << "foo0" << "bar0" << "foo1" << 1 << "foo2" << 314 << finalize;
std::cout << bsoncxx::to_json(doc) << std::endl << std::endl;
doc = editBsoncxx<std::string> (doc.view(), "foo1", "edited"); //replace "foo1" with string "edited"
doc = editBsoncxx<int>(doc.view(), "baz_noappend", 123, false); //do nothing if key "baz_noappend" is not found. <- if key-existance algorythm will be applied, we'd spend about o(lob(n)) here, not o(n)
doc = editBsoncxx<int>(doc.view(), "baz_append", 123, true); //key will not be found => it'll be appended which is default behaviour
std::cout << bsoncxx::to_json(doc) << std::endl;
Result:
{
"foo0" : "bar0",
"foo1" : 1,
"foo2" : 314
}
{
"foo0" : "bar0",
"foo1" : "edited",
"foo2" : 314,
"baz_append" : 123
}
So, in your case you can use
fruit = editBsoncxx<std::string>(fruit.view(), "orange", "ripe");
But, again, see already-mentioned related question you're right when saying that
the idea behind the builder is "just" to create a query to give to the database?
I think, the solution will be "do not edit documents".
also you can write something like type-converter from bsoncxx to other json storing fomat (for example, rapidjson)
Beware of {value:"valid_json"}: bsoncxx::to_json does not add backslashes to quote signs in values => injection can be made.