From OpenEMR Project Wiki
Submitting Patches to Upstream
Overview of submitting code
- Code patches for review can be submitted via a Pull Request on github at https://github.com/openemr/openemr/pulls
- See here for further instructions.
- Please derive patches/code from the most current OpenEMR development version from either of below repositories:
- The 'master' branch from the git repository on github: http://github.com/openemr/openemr (quick howto documentation here)
- The 'master' branch from the git repository on sourceforge: git://openemr.git.sourceforge.net/gitroot/openemr/openemr
- The 'master' branch from the git repository on repo.or.cz: git://repo.or.cz/openemr.git
Creating A Patch
- (You should never need to do below and much better to instead use git/github)
Creating patches with diff
Using diff is simple whether you are working with single files or entire source directories. To create a patch for a single file, use the form:
diff -u original.c new.c > original.patch
To create a patch for an entire source tree, make a copy of the tree:
cp -R original new
Make any changes required in the directory new/. Then create a patch with the following command:
diff -rupN original/ new/ > original.patch
That's all you need to get started with diff and patch. For more information use:
man diff man patch
Notifying the Development Team
Carriage Returns / Line Feeds
All text files for the project should have Unix-style line endings (i.e. no carriage returns). Developers who use a Windows desktop should also use a suitable text editor that respects this (last checked, EditPad Lite and Notepad++ are free examples). Git can also nicely automatically handle this for Windows users: http://help.github.com/line-endings/
General Development Best Practices
Copyright and Licensing
Each file in the source tree should begin with a copyright declaration, and information about what license the file is released under.
In order to verify that code changes pass certification tests, contributors must execute the relevant test cases via the test mapping document. This document is currently being built up (http://open-emr.org/wiki/index.php/Manual_Tests) and lives here: https://github.com/openemr/openemr/blob/master/tests/certification/tests.md
When placing a string from the database inside of an html attribute, or placing it as the text content of an html object, one should call htmlspecialchars() to provide appropriate escaping.
Many of the practices at http://www.odi.ch/prog/design/php/guide.php appear to be good rules when working with the OpenEMR source.
Please note that PHP 5.4.0 is the minimum version required for OpenEMR. This is enforced here: https://github.com/openemr/openemr/blob/master/common/compatibility/checker.php#L30
When including a file, make sure to use 'require_once', or use 'include_once' and check the return!
All blocks of PHP code should start with '<?php', and end with '; ?>'. for example: <?php echo $testvar; ?>
Line comments (C++-style) should only be used for comments that (a) appear "after" (in reading order) the code the are documenting and (b) appear on the same line as the code they are documenting.
Block comments (C-style) should be used for comments that (a) require multiple lines OR (b) require their own line. Block comments should appear before the code they document. Block comments are also used for notices that are not code documentation, such as copyright and licensing notices.
Depending on the scope of your work, you may need one or both comment styles.
Comments should never be used to "preserve" old code or mark individual changes. This information should be available through our version control system, and is rarely that useful anyway. Comments shouldn't answer the "How?" of the code; that's the role of the source code. Comments should answer the "Why?" of the code, what issues are being address by this code.
Comments that are doxygen-ready are appreciated, but we currently do not use doxygen to generate documentation. Using doxygen with PHP appears to have some rough edges, but it might be useful in the future.
Please go to How to Document Your Code Properly to get a good idea on how to document properly.
The current OpenEMR source is inconsistent about indentation using spaces or tabs. Changes to existing code should preserve the indentation style of the changed lines. Changes to existing files should follow the indentation style of the rest of the file for new lines; if the indentation style is inconsistent you may use any style currently in the file. In new files, try to use a style that already exists in the source code.
Possible Future Guidelines
For most code:
- Use a single tab for an indentation level. Outside of literal HTML, having code at more than 4 indentation levels is a good indicator the code should be re-factored.
- Use spaces for alignment. Alignment is only done between two lines with the same indentation level. Tabs appear before the spaces. Alignment is rare, but may be used when breaking an overly long line.
- Use a single space for a "half-indent". While not common in PHP code, the "half-indent" is often used for "case $n:" labels in C/C++ and for "public:"/"private:" labels in C++.
- Tabs after spaces should be avoided. Tabs should be represented as "\t" in string literals.
- Unnecessary whitespace at the end of lines should be avoided.
For columnar/tabular data in a fixed-width font, when the width of each column is known or can be determined.
- Use spaces for left/right padding of data items and headers out to the fixed column width.
- Use a single tab for the gap between columns.
The above guidelines allow both you can all other developers of the code to choose any tab stop width greater than the width of a single space character and have the code align itself nicely. The allows each developer to choose how much horizontal whitespace they need to efficiently read the code.
Avoid adding unnecessary empty lines.
Below is WRONG
echo "</br>\n"; ?>
To ensure consistent interpretation of scripts in HTML and XHTML, any script which might contain the ampersand ('&') or left-angle-bracket ('<') characters must begin with
on a line by itself and must end with
When need to encode variables, use the encodeURIComponent() function instead of using the escape() function (to ensure compatibility with utf-8 characters).
Each page in OpenEMR should be valid HTML 4.0, XHTML 1.0, or XHTML 1.1. the validator at http://validator.w3.org/ is useful for ensuring compliance.
For textual data that should not be interpreted as markup, use htmlspecialchars(). Using a second ("quote_style") argument of ENT_NOQUOTES minimizes the length of the resulting string and is safe for non-markup.
For (parts of) attribute values, use htmlspecialchars() and provide a second ("quote_style") argument of ENT_QUOTES. XHTML requires either single- or double-quote characters around all attribute values, and using ENT_QUOTES allows either of those characters to be used.
To ensure (X)HTML validity, element names and attribute names but be drawn from the standards, instead of any outside data source. Because of this no special processing should be required -- just make sure they are spelled correctly in the PHP code.
<?php $user_data = $_REQUEST['foo']; $db_data = sqlQuery('some SQL statement'); echo "<p class='$db_data'>$user_data</p>\n"; ?>
<?php $user_data = $_REQUEST['foo']; $db_data = sqlQuery('some SQL statement'); $para_class = htmlspecialchars($db_data, ENT_QUOTES); $para_content = htmlspecialchars($user_data, ENT_NOQUOTES); echo "<p class='$para_class'>$para_content</p>\n"; ?>
The basic rule of thumb is to use it on just code that is getting outputted to the screen (in html). So, not a good idea to do it to variables at the top of the file; need to do htmlspecialchars on them when you echo them onto the screen.
$date = $POST_['date'] ... echo htmlspecialchars($date)
$date = htmlspecialchars($POST_['date']) ... echo $date
Although sometimes you will build a variable just for output, then it's ok to hemlspecialchars that variable:
$string = "<b>".htmlspecialchars($string)."</b>" echo $string
The key is to realize that htmlspecialchars() function is altering that string specifically for html output, thus using this altered string in other ways (such as php, mysql, pdf output, network exchange) can break things.
it is preferred that CSS stylesheets contain all style related contents of our html forms. css stylesheets should also validate.
OpenEMR Specific Development Best Practices
All of your MySQL calls need to go through openemr/library/sql.inc or you will break the encoding (utf8). See that file for details and the large amount of example throughout code. NEVER, NEVER, NEVER use the native mysql_* calls.
PHP Sessions and Browser Windows
- The main php function used for translation is xl(), basically all of labels and messages have to go through this function. To learn about this function definition, parameters, and general use, please read this wiki page, and ensure you understand it.
- These things are what I consider the tenets of the xl() function:
- For coding new xl functions:
- 1. No trailing or leading whitespace.
- Below is WRONG
- Below is CORRECT
xl('Demographics') . ' ';
- Below is WRONG
- 2. No variables.
- Below is WRONG
xl('please type $name here');
- Below is CORRECT
xl('please type') . ' ' . $name . ' ' . xl('here');
- Below is WRONG
- 1. No trailing or leading whitespace.
- For previously coded xl functions:
- To be safe, just leave them be (the above rules do not apply).
- For previously coded xl functions:
- For example:
alert("Please type letters only");
- Should be:
alert("<?php echo xl('Please type letters only'); ?>");
- Do not use the text or values of your buttons or controls in your coding algorithm. For example, if you have a 'submit' button and use the 'submit' string(the 'value' of the button) in your algorithm, then it will not work if it's translated to another word.
For good examples, look through the code. If any questions don't hesitate to ask them on the sourceforge developer forums.
SQL Table Name Conventions
- Creating new SQL tables names with uppercase letters is NOT allowed. This is because these table names are difficult to support in both Windows and Linux. There are times, however, when this needs to be supported in the the following settings:
- Older code (aka the form_CAMOS module)
- Code that is beyond OpenEMR's control (for example, the RxNORM tables that are imported into OpenEMR).
- There is a method to support this (as of OpenEMR 4.1.2), so that these table are supported in both Linux and Windows. In order for this to work, you need to surround the table name with the mitigateSqlTableUpperCase() function. For example, it will look like this:
$query1 = "select id, category from ".mitigateSqlTableUpperCase("form_CAMOS_category");
- (You may wonder, what the heck does this do; this function will actually look up the table in mysql in a case insensitive manner and return the table name from mysql)
Access Control Objects
If you add a new Access Control Object to the OpenEMR codebase, then also add it to the following three sites:
- Header notes of the library/acl.inc file
- acl_setup.php file
- acl_upgrade.php file
We have a standardized method for sending emails. Please see here for details : Sending Email
Database Table Changes
Changes to the database schema are now versioned. Please increment the value of $v_database in version.php, so that we can know automatically when a database upgrade is required. This is checked in admin.php and if the versions differ, a manual upgrade is required.
Updates also need to be included in the database.sql and ####-to-####-upgrades.sql META files. See below for notes on using these files to support upgrades.
Upgrade SQL META Language
Comment Meta Language for sql upgrades (via the sql_upgrade.php script):
While these lines are as enigmatic as they are functional, there is a method to the madness. Let's take a moment to briefly go over proper comment meta language use. The best way to learn this is to look at examples in current/previous scripts.
-- The #If* sections have the behavior of functions and come complete with arguments supplied command-line style -- -- Your Comment meta language lines cannot contain any other comment styles such as the nefarious double dashes "--" lest your lines be skipped and the blocks automatcially executed with out regard to the existing database state. -- -- Comment Meta Language Constructs: -- -- #IfNotTable -- argument: table_name -- behavior: if the table_name does not exist, the block will be executed -- #IfTable -- argument: table_name -- behavior: if the table_name does exist, the block will be executed -- #IfMissingColumn -- arguments: table_name colname -- behavior: if the colname in the table_name table does not exist, the block will be executed -- #IfNotColumnType -- arguments: table_name colname value -- behavior: If the table table_name does not have a column colname with a data type equal to value, then the block will be executed -- #IfNotRow -- arguments: table_name colname value -- behavior: If the table table_name does not have a row where colname = value, the block will be executed. -- #IfNotRow2D -- arguments: table_name colname value colname2 value2 -- behavior: If the table table_name does not have a row where colname = value AND colname2 = value2, the block will be executed. -- #IfNotRow3D -- arguments: table_name colname value colname2 value2 colname3 value3 -- behavior: If the table table_name does not have a row where colname = value AND colname2 = value2 AND colname3 = value3, the block will be executed. -- #IfNotRow4D -- arguments: table_name colname value colname2 value2 colname3 value3 colname4 value4 -- behavior: If the table table_name does not have a row where colname = value AND colname2 = value2 AND colname3 = value3 AND colname4 = value4, the block will be executed. -- #IfNotRow2Dx2 -- desc: This is a very specialized function to allow adding items to the list_options table to avoid both redundant option_id and title in each element. -- arguments: table_name colname value colname2 value2 colname3 value3 -- behavior: The block will be executed if both statements below are true: -- 1) The table table_name does not have a row where colname = value AND colname2 = value2. -- 2) The table table_name does not have a row where colname = value AND colname3 = value3. -- #EndIf -- all blocks are terminated with and #EndIF statement.
Creating a list in list_options
Lists are a nice way to build customizable lists that support standardized output formatting and internationalization. See Administration->Lists for details and check out the list_options mysql table.
- Example of placement of new list in database.sql:
INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('lists','proc_specimen','Procedure Specimen Types', 1,0); INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('proc_specimen','blood' ,'Blood' ,10,0); INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('proc_specimen','saliva','Saliva',20,0); INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('proc_specimen','urine' ,'Urine' ,30,0); INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('proc_specimen','oth' ,'Other' ,90,0);
- Example of placement of new list in the upgrade sql file:
#IfNotRow2D list_options list_id lists option_id proc_specimen INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('lists','proc_specimen','Procedure Specimen Types', 1,0); INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('proc_specimen','blood' ,'Blood' ,10,0); INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('proc_specimen','saliva','Saliva',20,0); INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('proc_specimen','urine' ,'Urine' ,30,0); INSERT INTO list_options ( list_id, option_id, title, seq, is_default ) VALUES ('proc_specimen','oth' ,'Other' ,90,0); #EndIf
Note as demonstrated above that the seq entries increment in 10's, and that the option_id entry should not contain any blanks or caps.
These lists can be used to configuration of layouts in Administration->layouts, and can also use the functions in options.inc.php within scripts.
- Example of generating a item selector using the list(note the input variable will be $POST['form_proc_specimen']):
- Example of generating the title of the list from the option_id:
Creating a global configuration setting
As of version 4.0, these can be added to library/globals.inc.php . Then the variable can be called in code as so : $GLOBALS['yourVariableName'] . It can also then be configured by the user in Adminstration->Globals screen.