Add better documentation for Model

1 files changed, 88 insertions, 5 deletions

diff --git a/README.md b/README.md
index 40d7e62..3ddea35 100644
--- a/README.md
+++ b/README.md
@@ -1094,12 +1094,95 @@ The following objects exist in Oxidized.
  * 'sql', 'csv' and 'http' (supports any format with single entry per line, like router.db)
 
 ## Model
- * lists commands to gather from given device model
- * can use 'cmd', 'prompt', 'comment', 'cfg'
- * cfg is executed in input/output/source context
- * cmd is executed in instance of model
- * 'junos', 'ios', 'ironware' and 'powerconnect' implemented
+### At the top level
+A model may use several methods at the top level in the class. `cfg` is
+executed in input/output/source context. `cmd` is executed within an instance
+of the model.
 
+#### `cfg`
+`cfg` may be called with a list of methods (`:ssh`, `:telnet`) and a block with
+zero parameters.  Calling `cfg` registers the given access methods and calling
+it at least once is required for a model to work.
+
+The block may contain commands to change some behaviour for the given methods
+(e.g. calling `post_login` to disable the pager).
+
+#### `cmd`
+Is used to specify commands that should be executed on a model in order to
+gather its configuration. It can be called with:
+
+* Just a string
+* A string and a block
+* `:all` and a block
+* `:secret` and a block
+
+The block takes a single parameter `cfg` containing the output of the command
+being processed.
+
+Calling `cmd` with just a string will emit the output of the command given in
+that string as configuration.
+
+Calling `cmd` with a string and a block will pass the output of the given
+command to the block, then emit its return value (that must be a string) as
+configuration.
+
+Calling `cmd` with `:all` and a block will pass all command output through this
+block before emitting it. This is useful if some cleanup is required of the
+output of all commands.
+
+Calling `cmd` with `:secret` and a block will pass all configuration to the
+given block before emitting it to hide secrets if secret hiding is enabled. The
+block should replace any secrets with `'<hidden>'` and return the resulting
+string.
+
+Execution order is `:all`, `:secret`, and lastly the command specific block, if
+given.
+
+#### `comment`
+Called with a single string containing the string to prepend for comments in
+emitted configuration for this model.
+
+If not specified the default of `'# '` will be used (note the trailing space).
+
+#### `prompt`
+Is called with a regular expression that is used to detect when command output
+ends after a command has been executed.
+
+If not specified, a default of `/^([\w.@-]+[#>]\s?)$/` is used.
+
+#### `expect`
+Called with a regular expression and a block. The block takes two parameters:
+the regular expression, and the data containing the match.
+
+The passed data is replaced by the return value of the block.
+
+`expect` can be used to, for example, strip escape sequences from output before
+it's further processed.
+
+### At the second level
+The following methods are available:
+
+#### `comment`
+Used inside `cmd` invocations. Comments out every line in the passed string and
+returns the result.
+
+#### `password`
+Used inside `cfg` invocations to specify the regular expression used to detect
+the password prompt. If not specified, the default of `/^Password/` is used.
+
+#### `post_login`
+Used inside `cfg` invocations to specify commands to run once Oxidized has
+logged in to the switch. Takes one argument that is either a block (taking zero
+parameters) or a string containing a command to execute.
+
+#### `pre_logout`
+Used to specify commands to run before Oxidized closes the connection to the
+switch. Takes one argument that is either a block (taking zero parameters) or a
+string containing a command to execute.
+
+#### `send`
+Usually used inside `expect` or blocks passed to `post_login`/`pre_logout`.
+Takes a single parameter: a string to be sent to the switch.
 
 # Help Needed