Upgrade Rell

There are two kinds of breaking changes in Rell 0.10.x:

1. Rell Language:
   • Module System; include - deprecated and doesn't work.
   • Mount names: mapping of entities and objects to SQL tables changed.
   • class and record renamed to entity and struct, the code using old keywords doesn't compile.
   • Previously deprecated library functions are now unavailable; the code using them doesn't compile.
2. Configuration and tools:
   • Postchain blockchain.xml: now needs a list of modules instead of the main filename; module arguments are per-module.
   • Run.XML format: specifying module instead of main file; module arguments are per-module.
   • Command-line tools: accept a source directory path and main module name combination instead of the main .rell path.

Step-by-step upgrade

1. Read about the Module System.
2. Read about Mount Names.
3. Use the migrate-v0.10.sh tool to rename class, record, and deprecated function names (see below).
4. Manually update the source code to use the Module System instead of include.
5. Use @mount annotation to set correct mount names to entities, objects, operations, and queries (recommended to apply @mount to entire modules or namespaces, not to individual definitions).
6. Update configuration files if necessary (see the details below).
7. The Web IDE uses the root module as the main module, so ensure you have it and import all required modules there.

Details

migrate-v0.10.sh tool

The tool is in the postchain-node directory of a Rell distribution. It renames class, record, and most of the deprecated functions, e. g. requireNotEmpty() -> require_not_empty.

Usage: migrator [--dry-run] DIRECTORY
Replaces deprecated keywords and names in all .rell files in the directory (recursively)
      DIRECTORY   Directory
      --dry-run   Do not modify files, only print replace counts

Specify a Rell source directory as an argument, and the tool does renaming in all .rell files in that directory and its subdirectories.

UTF-8 encoding is always used by the tool. If files use a different encoding, some characters might get broken. It's recommended to not run the tool if there're uncommitted changes in the directory. After running it, review the changes it made.

blockchain.xml

New blockchain.xml Rell configuration looks like this (only changed parts shown):

<dict>
    <entry key="gtx">
        <dict>
            <entry key="rell">
                <dict>
                    <entry key="moduleArgs">
                        <dict>
                            <entry key="app.foo">
                                <dict>
                                    <entry key="message">
                                        <string>Some common message...</string>
                                    </entry>
                                </dict>
                            </entry>
                            <entry key="app.bar">
                                <dict>
                                    <entry key="x">
                                        <int>123456</int>
                                    </entry>
                                    <entry key="y">
                                        <string>Hello!</string>
                                    </entry>
                                </dict>
                            </entry>
                        </dict>
                    </entry>
                    <entry key="modules">
                        <array>
                            <string>app.foo</string>
                            <string>app.bar</string>
                        </array>
                    </entry>
                </dict>
            </entry>
        </dict>
    </entry>
</dict>

What's changed:

• gtx.rell.moduleArgs is now a dictionary, specifying module_args for multiple modules (in older versions, there was only one module_args for a Rell app, now, there can be one module_args per module).
• gtx.rell.modules is an array of module names.

run.xml

An example of a new run.xml file:

<run wipe-db="true">
    <nodes>
        <config src="node-config.properties" add-signers="false" />
    </nodes>
    <chains>
        <chain name="test" iid="1" brid="01234567abcdef01234567abcdef01234567abcdef01234567abcdef01234567">
            <config height="0">
                <app module="app.main">
                    <args module="app.bar">
                        <arg key="x"><int>123456</int></arg>
                        <arg key="y"><string>Hello!</string></arg>
                    </args>
                    <args module="app.foo">
                        <arg key="message"><string>Some common message...</string></arg>
                    </args>
                </app>
            </config>
        </chain>
    </chains>
</run>

What's changed:

• module tag replaced by app, which has module attribute.
• There can be multiple args elements, and each must have a module attribute.