DW CLI allows to execute queries and generate data directly from the command line.

Supported Data Formats are:

DW CLI is compiled with Graal AOT for fast bootstrap so download the one for your target os.

1. Download the zip Mac | Linux
2. Unzip the file on your <home_directory>/.dw
3. Add <home_directory>/.dw/bin to your PATH

If the directory containing the dw executable is in your PATH, you can run dw from anywhere. If it is not, go to the bin directory referenced in the installation instructions and run dw from there.

dw

.........................................................................
.%%%%%....%%%%...%%%%%%...%%%%...%%...%%..%%%%%%...%%%%...%%..%%..%%%%%%.
.%%..%%..%%..%%....%%....%%..%%..%%...%%..%%......%%..%%..%%..%%..%%.....
.%%..%%..%%%%%%....%%....%%%%%%..%%.%.%%..%%%%....%%%%%%..%%..%%..%%%%...
.%%..%%..%%..%%....%%....%%..%%..%%%%%%%..%%......%%..%%...%%%%...%%.....
.%%%%%...%%..%%....%%....%%..%%...%%.%%...%%%%%%..%%..%%....%%....%%%%%%.
.........................................................................


Usage:

dw [-p <weavePath>]? [-i <name> <path>]* [-v]? [-o <outputPath>]? [[-f <filePath>] | [-m <nameIdentifier>] | <scriptContent>]

Arguments Detail:

 --path or -p    | Path of jars or directories where weave files are being searched.
 --input or -i   | Declares a new input.
 --verbose or -v | Enable Verbose Mode.
 --output or -o  | Specifies output file for the transformation if not standard output will be used.
 --main or -m    | The full qualified name of the mapping to be execute.

 Examples

 dw -i payload <fullpathToUser.json> "output application/json --- payload filter (item) -> item.age > 17"

 Documentation reference:

 https://docs.mulesoft.com/mule-runtime/4.2/dataweave

Input file users.json

[
  {
    "name": "User1",
    "age": 19
  },
  {
    "name": "User2",
    "age": 18
  },
  {
    "name": "User3",
    "age": 15
  },
  {
    "name": "User4",
    "age": 13
  },
  {
    "name": "User5",
    "age": 16
  }
]

Let's query users old enough to drink alcohol:

dw -i payload <fullpathToUsers.json> "output application/json --- payload filter (item) -> item.age > 17"

cat <fullpathToUser.json> | dw "output application/json --- payload filter (item) -> item.age > 17"

dw "output application/xml --- users: {( 1 to 100 map (item) -> {user: "User" ++ item} )}" >> out.xml

• DW_HOME = The directory where the home will be found if not defined ~/.dw will be used
• DW_LIB_PATH = The directory where libraries are going to be search by default. If not defined ${DW_HOME}/libs will be used
• DW_DEFAULT_INPUT_MIMETYPE = The default mimeType that is going to be used for the standar input. If not defined application/json will be used
• DW_DEFAULT_OUTPUT_MIMETYPE = The default output mimeType that is going to be if not defined. If not defined application/json will be used

This specifies the path where to search it will also search on the DW_LIB_PATH env directory path.

DIRECTORY=<pick a directory>

cd $DIRECTORY

echo '%dw 2.0
fun addUnderscore(s: String): String = s ++ "_"' > utils.dwl

dw --path $DIRECTORY 'output application/json import * from utils --- {underscored: addUnderscore("hello")}'

An interesting use case for the CLI is to combine it with curl

We can use the Github API to query commits of a repo.

We can easily get the first commit by doing:

curl "https://api.github.com/repos/mulesoft/mule/commits?per_page=5" | dw "payload[0]"

or we can get the message by doing:

curl "https://api.github.com/repos/mulesoft/mule/commits?per_page=5" | dw "{message: payload[0].commit.message}"

This example will create a really big csv and it will stream it to the HTTP server on localhost.

dw "output application/csv --- (1 to 10000000000000000000000) map (item) -> {name: 'User \$(item)'}" | curl -X POST -T "/dev/stdin" http://localhost:8081/

For more info about the language see the docs site