Difference between revisions of "Dev Finding Things"

Revision as of 05:43, 31 January 2009

Grepping through code

In the directory you want to search:

rgrep -i [search term] *

To output the results of that search into a file in your home directory:

rgrep -i [search term] * > ~/filename.txt

Managing the database schema

The database schema is managed by editing update-db-general.pl. Update-db-general.pl is organized roughly like this so:

• mark which tables are clustered (versus global)
• table creation, post-create table population, table deletion
• table alteration

Functions you may need to use:

• creating a new table

register_tablecreate( "tablename", <<'EOC');
CREATE TABLE tablename (
  ....
)
EOC

• drop a table
  • remove the relevant register_tablecreate code
  • drop the table if it exists already (for older installations)

register_tabledrop( "tablename" );

• adding a column to an existing table
  • add the column to the register_tablecreate code, for new installations
  • add this to the bottom of register_alter, for existing installations

# check that the column does not yet exist
unless ( column_type( "tablename", "columname" ) ) {
   do_alter("tablename", "ALTER TABLE tablename ADD ..." );
}

• modifying a column in an existing table / modifying data in an existing table

Similar to adding a column, but instead of checking whether a table exists, you may want to check against index_name, table_relevant, column_type, e.g.,

 if ( index_name( ... ) ) {}

• initialize a table with data from another table on table creation

post_create( "tablename", /*sql statements/code. Look at other examples in the file */ );

To update your database with your changes, run

$LJHOME/bin/upgrading/update-db.pl -r --innodb

Properties

Properties are listed in bin/upgrading/proplists.dat, broken down into three sections and listed alphabetically within those sections:

1. userproplist (user properties)
2. talkproplist (comment properties)
3. logproplist (entry properties)

When removing, remove the property from the file, and also do a grep over the codebase to remove any code which uses this prop.

Translation strings

Translation strings are defined in a few different files:

• bin/upgrading/en.dat - central location for strings for the backend code, e.g., things in cgi-bin, hooks, widgets
• htdocs/page.bml.text - scattered throughout htdocs; partner to htdocs/page.bml

When removing a string, transfer it to deadphrases.dat. Deadphrases.dat lists phrases that are no longer in use, so that other installations can deactivate these strings as well when they update their code.

If the string you removed was from en.dat, put it into deadphrases as:

general prop.name.blah

If the string you removed is from a page, put it into deadphrases as:

general /page.bml.prop.name.blah

After making your changes, run

$LJHOME/bin/upgrading/texttool.pl load

to actually load the new/modified strings into your live environment.

Hooks

Hook implementations can be found in

Some hook documentation can be found in doc/raw/hooks.txt, but it is very outdated and incomplete, and probably should be ignored right now.

Memcache

A list of memcache keys can be found in doc/raw/memcache-keys.txt. You should update this if you add new memcache keys or change existing behavior.

Styles

• dw-free/bin/upgrading/s2layers.dat, dw-nonfree/bin/upgrading/s2layers-local.dat

Defines system layers + layer types + layer parents

• bin/upgrading/s2layers/$themename/layout.s2, bin/upgrading/s2layers/$themename/themes.s2

Contains actual layout layers, list of themes

• dw-free/cgi-bin/LJ/S2Themes.pm, dw-nonfree/cgi-bin/LJ/S2Themes-local.pm

Handles some logic surrounding themes, contains list of default themes for each layout

• cgi-bin/S2Themes/$layout

Contains logic for /customize/ and /customize/options.bml pages. Arranges properties into propgroups, puts themes into categories, contains designer