Once you start developing an application you’ll want to launch it in different contexts: in a production context the configuration must be optimized for speed and security while in a development context debugging capabilities and convenience are more important. Flow supports the notion of contexts which allow for bundling configuration for different purposes. Each Flow request acts in exactly one context. However, it is possible to use the same installation on the same server in distinct contexts by accessing it through a different host name, port or passing special arguments.
Why do I want contexts?
Imagine your application is running on a live server and your customer reports a bug. No matter how hard you try, you can’t reproduce the issue on your local development server. Now contexts allow you to enter the live application on the production server in a development context without anyone noticing – both contexts run in parallel. This effectively allows you to debug an application in its realistic environment (although you still should do the actual development on a dedicated machine …).
An additional use for context is the simplified staging of your application. You’ll want almost the same configuration on your production and your development server - but not exactly the same. The live environment will surely access a different database or might require other authentication methods. What you do in this case is sharing most of the configuration and define the difference in dedicated contexts.
Flow provides configuration for the Production and Development context. In the standard distribution a reasonable configuration is defined for each context:
- In the Production context all caches are enabled, logging is reduced to a minimum and only generic, friendly error messages are displayed to the user (more detailed descriptions end up in the log).
- In Development context caches are active but a smart monitoring service flushes caches automatically if PHP code or configuration has been altered. Error messages and exceptions are displayed verbosely and additional aids are given for effective development.
If Flow throws some strange errors at you after you made code changes,
make sure to either manually flush the cache or run the application in
Development context - because caches are not flushed automatically
The configuration for each context is located in directories of the same name:
|Configuration/||Global configuration, for all contexts|
|Configuration/Development/||Configuration for the
|Configuration/Production/||Configuration for the
Setting Up Context with Virtual Host and change Context from «Development» to «Production» is explained in the previous chapter «Installation».
One thing you certainly need to adjust is the database configuration. Aside from that Flow should work fine with the default configuration delivered with the distribution. However, there are many switches you can adjust: specify another location for logging, select a faster cache backend and much more.
The easiest way to find out which options are available is taking a look at the default
configuration of the Flow package and other packages. The respective files are located in
Packages/Framework/<packageKey>/Configuration/. Don’t modify these files directly but
rather copy the setting you’d like to change and insert it into a file within the global
or context configuration directories.
Flow uses the YAML format  for its configuration files. If you never edited a YAML file, there are two things you should know at least:
- Indentation has a meaning: by different levels of indentation, a structure is defined.
- Spaces, not tabs: you must indent with exactly 2 spaces per level, don’t use tabs.
More detailed information about Flow’s configuration management can be found in the Reference Manual.
If you’re running Flow on a Windows machine, you do have to make some
adjustments to the standard configuration because it will cause problems
with long paths and filenames. By default Flow caches files within the
whose absolute path can eventually become too long for Windows.
To avoid errors you should change the cache configuration so it points to a
location with a very short absolute file path, for example
Do that by setting the
FLOW_PATH_TEMPORARY_BASE environment variable -
For example in the virtual host part of your Apache configuration:
<VirtualHost ...> SetEnv FLOW_PATH_TEMPORARY_BASE "C\\:tmp\\" </VirtualHost>
Parsing the YAML configuration files takes a bit of time which remarkably slows down the initialization of Flow. That’s why all configuration is cached by default when Flow is running in Production context. Because this cache cannot be cleared automatically it is important to know that changes to any configuration file won’t have any effect until you manually flush the respective caches.
To avoid any hassle we recommend that you stay in Development context throughout this tutorial.
Before you can store anything, you need to set up a database and tell Flow how to access it. The credentials and driver options need to be specified in the global Flow settings.
You should make it a habit to specify database settings in context-specific configuration files. This makes sure your functional tests will never accidentally truncate your production database. The same line of thought makes sense for other options as well, e.g. mail server settings.
After you have created an empty database and set up a user with sufficient access
rights, copy the file
Configuration/Development/Settings.yaml. Open and adjust the file to your needs -
for a common MySQL setup, it would look similar to this:
Neos: Flow: persistence: backendOptions: dbname: 'gettingstarted' user: 'myuser' password: 'mypassword'
For global settings and Production context, the relevant files would be directly
Configure your MySQL server to use the
utf8_unicode_ci collation by default if possible!
If you configured everything correctly, the following command will create the initial table structure needed by Flow:
$ ./flow doctrine:migrate Migrating up to 2011xxxxxxxxxx from 0 ++ migrating 20110613223837 -> CREATE TABLE flow_resource_resourcepointer (hash VARCHAR(255) NOT NULL, PRIMARY -> CREATE TABLE flow_resource_resource (persistence_object_identifier VARCHAR(40) ... ------------------------ ++ finished in 4.97 ++ 5 migrations executed ++ 28 sql queries
|||YAML Ain’t Markup Language http://yaml.org|