Files with newlines cannot be opened

[prmr]

Description JetUML writes out a diagram in json format as a single line and expects to read it back in as a single line. This is unnecessarily brittle, especially when one wants to automatically format a diagram file to look at it. We should tolerate files with line breaks.

Steps to reproduce

1. Create a diagram
2. Save the diagram in a file
3. Open the file with a text editor and add a few line breaks that don't invalidate the json syntax or schema, e.g., between values and keys. Save the file.
4. Try to open the file with JetUML and a syntax error will be reported.

Screenshots

Configuration

• JetUML Release: 3.6