This topic includes some examples of using File Watchers.

• Example: Dataset Creation and Import
• Example: Named Capture Groups
• Example: Capture the Dataset Name
• Example: Capture both the Folder Destination and the Dataset Name
• Example: Using the Parameter Function

Example: Dataset Creation and Import

Suppose you want to create a set of datasets based on Excel and TSV files, and load data into those datasets. To set this up, do the following:

• In the File web part create a directory named 'watched'. (It is important that you do this before saving the File Watcher configuration.)
• Prepare your Excel/TSV files to match the expectations of your study, especially, time point-style (date or visit), ParticipantId column name, and time column name. The name of your file should not include any numbers, only letters.
• Upload the file into the study's File Repository.
• Create a trigger to Import/reload study datasets using data file.
• Location to Watch: enter 'watched'.
• File Pattern: Leave blank. The default file pattern will be used, which is (^\D*)\.(?:tsv|txt|xls|xlsx) Note that this file pattern will not match file names which include numbers.
• When the trigger is enabled, datasets will be created and loaded in your study.

Example: Named Capture Group <study>

Consider a set of data with original filenames matching a format like this:

sample_2017-09-06_study20.tsv
sample_2017-09-06_study21.tsv
sample_2017-09-06_study22.tsv

An example filePattern regular expression that would capture such filenames would be:

sample_(.+)_(?<study>.+)\.tsv

Files that match the pattern are acted upon, such as being moved and/or imported to tables in the server. Nothing happens to files that do not match the pattern.

If the regular expression contains named capturing groups, such as the "(?<study>.+)" portion in the example above, then the corresponding value (in this example "study20") can be substituted into other property expressions. For instance, a Move to container setting of:

/studies/${study}/@pipeline/import/${now:date}

would resolve into:

/studies/study20/@pipeline/import/2017-11-07 (or similar)

This substitution allows the administrator to determine the destination folder based on the name, ensuring that the data is uploaded to the correct location.

Example: Capture the Dataset Name

A File Watcher that matches .tsv/.xls files with "StudyA_" prefixed to the file name. For example, "StudyA_LabResults.tsv". Files are moved, and the data imported, to the StudyA folder. The <name> capture group determines the name of the dataset, so that "StudyA_LabResults.tsv" becomes the dataset "LabResults".

Example: Capture both the Folder Destination and the Dataset Name

To distribute files like the following to different study folders:

StudyA_Demographics.tsv
StudyB_Demographics.tsv
StudyA_LabResults.tsv
StudyB_LabResults.tsv

Example: Using the Parameter Function

The Parameter Function is a JavaScript function which is executed during the move. In the example below, the username is selected programmatically:

var userName = sourcePath.getNameCount() > 0 ? sourcePath.getName(0) : null;
var ret = {'pipeline, username': userName }; ret;

Related Topics

• File Watchers