Configuring User File Uploads
Overview
Users can upload their own files into PhixFlow using actions. This can be done using either a Table-action which links to a File Collector, or an Actionflow containing a file upload node. This will allow users to:
- Upload images/files and store the details of where to access them as a record.
- Upload files to be used in an analysis model. These files can be made available for users to download.
Example
In a simple contacts application, it is possible using file uploads to:
- Allow an application user to upload their own image against a contact:
- Bulk upload Excel files containing multiple contacts to appear within an application.
- Download files stored on the server. These could be previous file uploads.
Solution
Images and files are stored on the server when uploaded by a file collector. These files are placed into a standard directory and need to be moved into an appropriate directory which can be accessed by the front end. See your system administrator for help creating these directories.
Once the new directory has been created, the following is required:
- an action configured to upload a file
- an analysis model containing a file collector and a table
- a task plan that runs the analysis model
This is a worked example to set up a model that collects an uploaded file, moves it, and all the upload subdirectories, to the required new directory using an archive location on a file collector, to tell the collector where to move the file once it has been processed.
When files are uploaded via an action, they are initially stored under the default upload directory, this is specified in your system configuration. For example:
/opt/phixflow/data/phixflow/upload
A subdirectory is created for each uploaded file, in the form:
/opt/phixflow/data/phixflow/upload/[tag]/in/[uploadDate]/[uploadID]/[filename]
where
- [tag] is the tag specified by the action or file collector,
- [uploadDate] is the date of upload represented in a numerical string,
- [uploadID] is a unique string used to identify each file, and
- [filename] is the name of the uploaded file.
When uploading files through the front end we aim to move the files to a location under (either directly or via soft link) the below directory while preserving these subdirectories in order to uniquely reference each file.
/opt/phixflow/data/phixflow/datalink
1. Creating the Action to Upload a File
- In the File Upload section, tick File Upload and enter a Tag Expression (e.g. "contact").
- The exact tag used does not matter but needs to be used later to reference the upload location.
- Ticking File Upload means that running the action will trigger a file upload prompt, allowing the user to select a file to upload:
2. Creating the Analysis Model
- Create a new analysis model and create a File Collector. Apply the following settings:
2. Next create a Calculate Table from the File Collector.
3. On the new table, create 4 attributes with the following settings:
Attributes | ||||
---|---|---|---|---|
Property | 1 | 2 | 3 | 4 |
Name | UploadDate | UploadID | FileName | FileLocation |
Type | String | String | Bigstring | String |
Length | 10 | 50 | 1000 | |
Expression | toString(today(), "YYYYMMdd") | _context._fileUploadId | in._fileName | 'url("https:datalink/[dir]/" + _out.UploadDate + "/" + _out.UploadID + "/" + _out.FileName + '")' where _[dir] is the directory used to store the uploaded files |
Purpose | Converts today's date into a string | uses context variable to return the upload ID string. | The internal variable _fileName is available when running a file collector, and returns the name of the file that has been uploaded. It must be prefixed with a pipe name. | Example 'url("https:datalink/ContactImages/" + _out.UploadDate + "/" + _out.UploadID + "/" + _out.FileName + '")' This expression uses the upload date, upload ID and file name to build the URL containing the directory path of the uploaded file after it has been moved by the file collector. The URL is what is referenced by CSS properties to display the image. |
3. Creating the Task Plan
- Create a new task plan
- Create an analysis task which runs the above table
- On the created action, in the Run Task Plan section tick Run Selected Task Plan, and add the new task plan.
This means that after the action prompts the user to upload a file
- the table will be run,
- which in turn runs the file collector
- the file collector finds the file in the upload location and moves it to the new directory used to store the files
- the table then pulls through the file details generating its new location in the attribute FileLocation. This attribute can then be used whenever the file needs to be referred to.
4. Referencing Images on the Server
Once the user has identified the correct directory to store the file, it can be referenced using a URL. This URL must be in the format:
url("[File Location]") For example: url("https:datalink/MyProject/MyImage.png")
This URL is the value that needs to be stored and is referenced to display the image using CSS properties. Using the above example, the user stores the url of an image against each user in an attribute called 'ContactImage'. You can display this image on an area inside a card container using the following style settings:
- Name: background-image
- Expression: _form.ContactImage
- Name: background-repeat
- Expression: no-repeat
- Name: background-size
- Expression: choose size – could be 100%, 20px, auto (see Adding Images)
Changing Images on the Server
To change the image displayed in PhixFlow, upload a replacement image with the same name. The new image overwrites the original image. The existing URL continues to work and displays the new image. If the image name changes on the server, you need to update all the URLs that point to it.
Browsers cache images, if this happens the image will not change on the front end. To resolved this clear your browser cache and refresh the screen to display the updated image.