Reading JSON Using fastn
get-data processor is used to get data from a JSON files in the package.-- import: fastn/processors as pr
-- string foo:
$processor$: pr.get-data
file: foo.json
Lang:
ftd
This will read the key
foo from foo.json and store it in the variable named
foo.Key
By default, the name of the variable or list where the data is being store is
used as the key. You can overwrite the key using
key attribute:-- import: fastn/processors as pr
-- string foo:
$processor$: pr.get-data
key: some-other-key-instead-of-foo
file: foo.json
Lang:
ftd
Default Value
If the data is not found, we use the body as default value if body is available.
-- import: fastn/processors as pr
-- string foo:
$processor$: pr.get-data
"hello world"
Lang:
ftd
The body must be valid json, compatible with the data type on which we are
using the
get-data processor.Default Value in Caption For Primitive Types
For primitive types like
integer,
boolean, string etc, the default value can also be provided in the caption.
E.g.-- import: fastn/processors as pr
-- string foo: hello world
$processor$: pr.get-data
Lang:
ftd
Providing both
body and caption when using get-data is an error.Tutorial
We will be reading the data from JSON file and injecting the value to the caller
of the processor (caller could be variable or component).
Creating index.ftd
We need to make two files i.e. one file should be
index.ftd and another
file should be foo.jsonindex.ftd-- import: fastn/processors as pr
-- record person:
caption name:
integer age:
string gender:
-- person arpita:
$processor$: pr.get-data
file: foo.json
-- ftd.text: $foo.name
-- ftd.text: $foo.age
-- ftd.text: $foo.gender
Lang:
ftd
NOTE:
file must point to a valid json file with extension .json.Creating foo.json
{
"name": "arpita",
"age": 15,
"gender": "female"
}
Lang:
json
Running
Run
fastn serve and view 127.0.0.1:8000 (use whatever port reported by
fastn serve), and you should see something like this:arpita
15
female
Lang:
txt
