Running SUSHI
Note
This documentation assumes you have a SUSHI-compliant project structure and configuration as discussed in the previous sections.Running SUSHI
SUSHI is executed from the command line. The general form of the SUSHI execution command is as follows:
sushi {specification-directory} {options}
where options include the following (in any order):
-o, --out <out> the path to the output folder
-d, --debug output extra debugging information
-p, --preprocessed output FSH produced by preprocessing steps
-s, --snapshot generate snapshot in Structure Definition output (default: false)
-i, --init initialize a SUSHI project
-v, --version print SUSHI version
-h, --help output usage information
Tip
If you run SUSHI from your FSH project directory, and accept the defaults, the command can be shortened tosushi .
Note
By default, SUSHI only generates the profile differential, allowing the IG Publisher to create the profile snapshot. This is the approach recommended by HL7 FHIR leadership. If authors prefer, the-s option can be used to cause SUSHI to generate the snapshot without having to run the IG Publisher.
While SUSHI is running, it will print status messages as it processes your project files. When SUSHI has completed, you should receive a summary like the following:
╔════════════════════════ SUSHI RESULTS ══════════════════════════╗
║ ╭──────────┬────────────┬───────────┬─────────────┬───────────╮ ║
║ │ Profiles │ Extensions │ ValueSets │ CodeSystems │ Instances │ ║
║ ├──────────┼────────────┼───────────┼─────────────┼───────────┤ ║
║ │ 1 │ 1 │ 1 │ 1 │ 1 │ ║
║ ╰──────────┴────────────┴───────────┴─────────────┴───────────╯ ║
║ ║
╠═════════════════════════════════════════════════════════════════╣
║ O-fish-ally error free! 0 Errors 0 Warnings ║
╚═════════════════════════════════════════════════════════════════╝
Error Messages
In the process of developing your IG using FSH, you may encounter SUSHI error messages (written to the command console). Most error messages point to a specific line or lines in a .fsh file. If possible, SUSHI will continue, despite errors, to produce FHIR artifacts, but those artifacts may omit problematic rules. SUSHI should always exit gracefully. If SUSHI crashes, please report the issue using the SUSHI issue tracker.
Here are some general tips for debugging:
- Parsing (syntax) errors should be fixed first. A single syntax error can ballooon into many other errors, so you should always eliminate syntax errors first. Syntax error messages may include
extraneous input {x} expecting {y},mismatched input {x} expecting {y}andno viable alternative at {x}. These messages indicate that the line in question is not a valid FSH statement. - The order of keywords matters. The declarations must start with the type of item you are creating (e.g., Profile, Instance, ValueSet).
- The order of rules usually doesn’t matter, but there are exceptions. Slices and extensions must be created before they are constrained.
- Rules must contain valid paths. The
No element found at patherror means that although the overall grammar of the rule may be correct, SUSHI could not find the FHIR element you are referring to in the rule. Make sure there are no spelling errors, the element names in the path are correct, and you are using the path grammar correctly. - The community can help. If you are getting an error you can’t resolve, you can ask for help on the #shorthand chat channel.
SUSHI Outputs
Based on the inputs in FSH files, sushi-config.yaml, and the IG project directory, SUSHI populates the fsh-generated directory. For example, running SUSHI on the customized-ig project from the Project Structure section would add a fsh-generated folder as shown below:
customized-ig
├── fsh-generated
| └── resources
| ├── CodeSystem-myCodeSystem.json
| ├── Patient-myPatient-example.json
| ├── StructureDefinition-myExtension.json
| ├── StructureDefinition-myProfile.json
| ├── ValueSet-myValueSet.json
| └── ImplementationGuide-myIG.json
├── ig.ini
├── input
| ├── fsh
│ | └── (fsh files)
│ ├── ignoreWarnings.txt
│ ├── images
│ │ ├── myDocument.pdf
│ │ ├── myGraphic.png
│ │ └── mySpreadsheet.xlsx
│ ├── includes
│ │ └── menu.xml
│ ├── pagecontent
│ │ ├── index.md
│ │ ├── 2_mySecondPage.md
│ │ ├── 3_myThirdPage.md
│ │ └── 4_myFourthPage.md
├── package-list.json
└── sushi-config.json
SUSHI creates only the fsh-generated folder, but some of the files shown above are either processed by SUSHI to create the ImplementationGuide.json file, or can be generated by SUSHI if the author wishes. See the breakdown of files and directories below:
- fsh-generated*: Generated from the definitions in the input/fsh/*.fsh files.
- ig.ini: Specified by the author and unchanged by SUSHI.
- input/ignoreWarnings.txt: Specified by the author and unchanged by SUSHI.
- input/images/*: Specified by the author and unchanged by SUSHI.
- input/includes/menu.xml: Specified by the author and unchanged by SUSHI, but can alternately be specified via the
menuproperty in sushi-config.yaml. If themenuconfiguration property is used, the output is generated to fsh-generated/includes/menu.xml. - input/pagecontent/*: Specified by the author, numeric prefixes are used by SUSHI in generating the ImplementationGuide-myIG.json file.
- package-list.json: Specified by the author and unchanged by SUSHI.
Downloading the IG Publisher Scripts
To run the IG Publisher, we recommend downloading the _updatePublisher.bat|sh and _genonce.bat|sh scripts provided by the sample-ig project. To get these scripts, download the sample-ig project, unzip it, and copy all of the .bat and .sh files to the directory above the fsh-generated directory (customized-ig in the example above).
Downloading the IG Publisher
After copying these, change directories in the command prompt to the directory above the fsh-generated directory. At the command prompt, enter:
_updatePublisher
./_updatePublisher.sh
This will download the latest version of the HL7 FHIR IG Publisher tool into the /input-cache directory. This step can be skipped if you already have the latest version of the IG Publisher tool in input-cache.
Tip
If you are blocked by a firewall, or if for any reason_updatePublisher fails to execute, download the current IG Publisher jar file here. When the file has downloaded, move it into the input-cache directory (which you may need to create as a sibling to the input directory).
Running the IG Publisher
Warning
If you have never run the IG Publisher, you may need to install Jekyll first. See Installing the IG Publisher for details.After the IG Publisher has been successfully downloaded, execute the following command to run it:
_genonce
./_genonce.sh
This will run the HL7 IG Publisher, which may take several minutes to complete. After the publisher is finished, open the file /output/index.html in a browser to see the resulting IG.
Tip
When running SUSHI, the IG Publisher will look for an optional fsh.ini control file in the root directory of the project (the same directory that contains ig.ini). This file should have [FSH] on the first line, and can include a sushi-version property, used to specify which version of SUSHI the IG Publisher should use, and a timeout property, used to set a timeout for SUSHI (in seconds). The default timeout is 60 seconds. An example fsh.ini file is provided below.
[FSH]
sushi-version = 0.16.0
timeout = 120
Preprocessed FSH
When running SUSHI, the -p or --preprocessed flag can be used to to create a _preprocessed folder in SUSHI’s output folder (customized-ig/_preprocessed in the example above). This folder will contain representations of the input FSH after several preprocessing steps have taken place. These steps include resolution of Alias values, insertion of RuleSet rules, and resolution of soft indexing. This is mainly provided as a debugging tool, for the author to verify that SUSHI is preprocessing the input FSH in an expected way, and to help trace errors in the output of SUSHI back to their source. For example, if the IG Publisher reports an error on element Bundle.entry[56].resource, it may be difficult to identify the problematic entry in your FSH source if you used soft-indexing. It is much easier, however, to identify the problematic element in the preprocessed FSH that contains explicit indices.
The example below shows a FSH snippet and a preprocessed version of that snippet. In this snippet, a Profile is defined using a RuleSet and an Alias, and below an Instance is defined which uses soft indexing.
Alias: CAT = http://hl7.org/fhir/ValueSet/observation-category
Profile: ObservationProfile
Parent: Observation
* insert Metadata
* category from CAT (required)
RuleSet: Metadata
* ^version = "1.2.3"
* ^publisher = "Example publisher"
Instance: PatientInstance
InstanceOf: Patient
* name.given[+] = "John"
* name.given[+] = "Q"
The preprocessed version of the above FSH is shown below. The CAT alias has been resolved to its full URL, the rules contained in the RuleSet have been inserted onto the ObservationProfile, and the RuleSet itself has been removed, and the rules on the PatientInstance have been resolved to fully specified paths, which do not use soft indexing.
Alias: CAT = http://hl7.org/fhir/ValueSet/observation-category
// Originally defined on lines 3 - 6
Profile: ObservationProfile
Parent: Observation
Id: ObservationProfile
* ^version = "1.2.3"
* ^publisher = "Example publisher"
* category from http://hl7.org/fhir/ValueSet/observation-category (required)
// Originally defined on lines 12 - 15
Instance: PatientInstance
InstanceOf: Patient
Usage: #example
* name.given[0] = "John"
* name.given[1] = "Q"