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Updated README.md

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Benoît Blanchon
2014-07-23 12:14:59 +02:00
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JsonGenerator/README.md
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@ -15,7 +15,7 @@ Features
* Elegant API, very easy to use
* Fixed memory allocation (no malloc)
* Small footprint
* Implements Arduino's Printable interface
* Implements Arduino's `Printable interface
* MIT License
@ -26,7 +26,7 @@ Example
array.add<6>(48.756080);
array.add<6>(2.302038);
JsonHashTable<3> root;
JsonObject<3> root;
root.add("sensor", "gps");
root.add("time", 1351824120);
root.add("data", array);
@ -50,12 +50,19 @@ Just add the following lines at the top of your `.ino` file:
#include <JsonGenerator.h>
using namespace ArduinoJson::Generator;
> ##### Having a namespace conflict?
> To be able to use both `ArduinoJson::Generator` and `ArduinoJson::Parser` in the same file, you need to do one of the followings:
>
> * Put the `using` statements into different functions
> * `using namespace ArduinoJson`, then prefix the type names by `Generator::` or `Parser::`
> * Create aliases for the namespaces or the types (C++11 only)
### 3. Create object tree
In order to generate a JSON string, you need to build the equivalent object tree. You usually start by the root which can be either an array or an hash-table.
In order to generate a JSON string, you need to build the equivalent object tree. You usually start by the root which can be either a JSON Array or a JSON Object.
#### Array
#### JSON Array
You create an array with the following line:
@ -91,22 +98,22 @@ Finally you can add nested object to the array:
or
JsonHashTable<8> nestedHash;
array.add(nestedHash);
JsonObject<8> nestedObject;
array.add(nestedObject);
#### Hash-table
#### JSON Object
You create a hash-table with the following line:
You create a JSON object (ie hash-table/dictionary) with the following line:
JsonHashTable<8> hash;
JsonObject<8> object;
Like with the array class, there is a template parameter that gives the capacity of the hash-table.
Like with the array class, there is a template parameter that gives the capacity of the object.
Then you can add strings, integer, booleans, etc:
hash.add("key1", "bazinga!");
hash.add("key2", 42);
hash.add("key3", true);
object.add("key1", "bazinga!");
object.add("key2", 42);
object.add("key3", true);
As for the arrays, there are two syntaxes for the floating point values:
@ -116,12 +123,12 @@ As for the arrays, there are two syntaxes for the floating point values:
Finally you can add nested objects:
JsonArray<8> nestedArray;
hash.add("key6", nestedArray);
object.add("key6", nestedArray);
or
JsonHashTable<8> nestedHash;
hash.add("key7", nestedHash);
JsonObject<8> nestedObject;
object.add("key7", nestedObject);
### 4. Get the JSON string
@ -133,7 +140,7 @@ Both ways are the easy way :-)
#### Use a classic `char[]`
Whether you have a `JsonArray` or a `JsonHashTable`, simply call `printTo()` with the destination buffer, like so:
Whether you have a `JsonArray` or a `JsonObject`, simply call `printTo()` with the destination buffer, like so:
char buffer[256];
array.printTo(buffer, sizeof(buffer));
@ -149,7 +156,7 @@ or
array.printTo(Serial);
> ##### About the Printable interface
> `JsonArray` and `JsonHashTable` implement Arduino's `Printable` interface.
> `JsonArray` and `JsonObject` implement Arduino's `Printable` interface.
> This is why you can call `Serial.print()` like in the example above.
> You can do the same with any other implementation of `Print`: `HardwareSerial`, `SoftwareSerial`, `LiquidCrystal`, `EthernetClient`, `WiFiClient`...
@ -161,7 +168,7 @@ Here are the size of the main classes of the library.
This table is for an 8-bit Arduino, types would be bigger on a 32-bit processor.
| Type | Size in bytes |
| ---------------------- | ------------- |
| JsonArray&lt;N&gt; | 8 + 6 x N |
| JsonHashTable&lt;N&gt; | 8 + 8 x N |
| Type | Size in bytes |
| --------------------| ------------- |
| JsonArray&lt;N&gt; | 8 + 6 x N |
| JsonObject&lt;N&gt; | 8 + 8 x N |