List<JsonObject> about arduinojson

[bblanchon]

Hi,

To generate the following JSON:

[{"key1":"value1"},{"key2":"value2"}]

you need to create a JsonArray with two nested JsonObject:

StaticJsonBuffer<200> jsonBuffer;

JsonArray& array = jsonBuffer.createArray();

JsonObject& obj1 = array.createNestedObject();
obj1["key1"] = "value1";

JsonObject& obj2 = array.createNestedObject();
obj2["key2"] = "value2";

array.printTo(Serial);

Please keep in mind that this is a serialization library, not a high performance collection library.

In particular, there is no way to remove an element from an array.
Although this particular feature could easily be added, it would not be efficient in term of memory management because the library was not designed for that in the first place.

If you need to manipulate collection in you program, you should consider std::vector, then use ArduinoJson only for the serialization.

Regards,
Benoit

[tiagotaz]

Thank you for answering my questions is working perfectly this way, only my questions about the removal of an array item that does not yet found a way to do.

[bblanchon]

Glad I could help.

I can easily add JsonArray::removeAt(int index) to remove an element in a array.
However, you must understand that the memory in the JsonBuffer will not be released.
It can be OK if you just remove one or two elements.
But if you need to remove elements repeatedly, it would be extremely inefficient.

Do you think that would be suitable for you?

[tiagotaz]

Got it, really think that would be complicated, my idea was to create a temporary list that would be allocated objects and through the iterator they would be removed. now do not know what would be better option to dynamically work objects

Enviado do meu iPhone

Em 21/12/2014, às 15:01, Benoît Blanchon [email protected] escreveu:

It can be OK if you just remove one or two elements.
But if you need to remove elements repeatedly, it would be extremely inefficient.

Do you think that would be suitable for you?

[bblanchon]

Again, ArduinoJson is a library to serialize arrays and objects in JSON, I'm not sure it's really suitable for your needs.
If I were you, I would store that "temporary list" in a native array or a STL container like std::list or std::vector.

Can you disclose a little more information about your project?
I could try to give you better advices.

[tiagotaz]

Hi,i need To implement the function remove can You help me ?

[bblanchon]

I added issue #58, I'll try to do that ASAP.

[bblanchon]

@tiagotaz: I added the JsonArray::removeAt() in the master branch. Sorry for the delay.

[tiagotaz]

Great!!!!!!!!! very thank's

Tiago de Almeida
(11)9-8204-4454

2015-05-02 10:17 GMT-03:00 Benoît Blanchon [email protected]:

@tiagotaz https://github.com/tiagotaz: I added the
JsonArray::removeAt() in the master branch. Sorry for the delay.

—
Reply to this email directly or view it on GitHub
#38 (comment)
.