Getting Request Data
`request-data` processor can be used to find the data from the HTTP request.
Query string and [named-path parameters](/dynamic-urls/) or from request body.
⚠️
Static Vs Dynamic
This feature works better with dynamic hosting. If you are using `fastn` in
[static site mode](/deploy/), then how the page looked when `fastn build` was
called will be shown to everyone. But if you are using [dynamic
mode](/deploy/) then this page would be regenerated on every page load.
Reading Individual Fields
Say the request was:
curl 'http://127.0.0.1:8000/test/?message=hello%20world'
Lang:
sh
And you wanted to extract the value of `message`, you can do it like this:
-- import: fastn/processors as pr
-- string message:
$processor$: pr.request-data
-- ds.markdown: $message
Lang:
ftd
Note that the field must be present or else this will give an error.
Using Default Value As Fallback
If you expect the message to be optional, maybe the user made a request like
this:
curl 'http://127.0.0.1:8000/test/'
Lang:
sh
without passing `message`, the earlier code will return HTTP 500 Error ([this
is a bug, should return 404](https://github.com/fastn-stack/fastn/issues/1103)),
one way to avoid that is to specify a default value:
-- import: fastn/processors as pr
-- string message: hello
$processor$: pr.request-data
-- ds.markdown: $message
Lang:
ftd
In this case we have provided a default value of `hello`, so if `message` is not
found the HTTP request, the variable `message` be assiged the default value,
`hello`.
Reading Multiple Bits In One Go
You can use a record to read multiple data from request.
curl 'http://127.0.0.1:8000/test/?message=hello%20world&flag=true'
Lang:
sh
In above example url contains query parameter `message` with value `hello
world` and `flag` with value `true`. We can access them `ftd` file by using
`request-data` processor.
-- import: fastn/processors as pr
-- record r-data:
string message: default value of message
boolean flag:
-- r-data data:
$processor$: pr.request-data
-- ds.markdown: $data.message
Lang:
ftd
Please note that all the parameters defined in the record must be present, or
they must have a default value.
Key Values In Dynamic URLs And Sitemap
When using [dynamic URLs](/dynamic-urls/) or the
[sitemap](/understanding-sitemap/-/build/), the key value parameters can also
be extracted using the same method:
-- fastn.dynamic-urls:
# RD Test:
url: /rd-test/<string:message>/
document: ftd-host/r.ftd
flag: false
Lang:
ftd
Here we have specified `flag: false` in the dynamic URL configuration, and it
will be picked up.
JSON Body
If the request body is not empty, and has content type `application/json`, the
body is parsed as JSON and the fields in your record are looked in the JSON as
well.
Note On Priority
If a field is present in more than one places, this is the order of preference:
- data in `FASTN.ftd` is highest priority
- then comes data in JSON body
- then the data in the named parameter
- and finally the GET query parameter is lowest priorty
