JS Styleguide

These are merely guidelines. They should not be adhered to mechanically, especially if a deviation would make your code more readable.

General

1. Code SHOULD be indented with spaces only.
2. Each level of indentation SHOULD consist of 4 spaces.
3. Files SHOULD include the Apache License Version 2 notice and the OSAF copyright notice at the top.
4. Lines SHOULD be 80 characters max.

Naming

Overview

Notes

1. Variable/method names in all lowercase with underscores SHOULD NOT be used unless mimicking another API.
   • Incorrect:

     wizard_hat, vorpal_blade

   • Correct:

     wizardHat, vorpalBlade

2. Acronyms in variable/method names SHOULD NOT be upppercased.
   • Incorrect:

     bartenderNPC, newRPG

   • Correct:

     bartenderNpc, newRpg

3. Variable/method names SHOULD be written in English.
   • Incorrect:

     dekaiKatana

   • Correct:

     giganticSword

4. Variable/method names SHOULD NOT be abbreviated to the point of being unclear.
   • Incorrect:

     wndMnstr[3]

   • Correct:

     wanderingMonster[3]

Variables

1. Variables SHOULD be initialized where they are declared, if possible in a way that indicates what type of value they will hold. Null initializations are acceptable.
   • Incorrect:

     var magicItemCount;
     var wizardNpc;

   • Correct:

     var magicItemCount = 0;
     var wizardNpc = null;

2. Variable declarations SHOULD NOT include extra spaces before the equals sign to align the variable values.
   • Incorrect:

     var currentThiefLevel = 8;
     var canBackstab       = true;
     var isNpc             = true;

   • Correct:

     var currentThiefLevel = 8;
     var canBackstab = true;
     var isNpc = true;

3. Variable names SHOULD NOT include 'temp' or 'tmp'. -- all local variables are by definition temporary.
   • Incorrect:

     tempString, tmpDate

   • Correct:

     str, dt

4. Magic numbers SHOULD NOT be used. Use a constant instead.
   • Incorrect:

     42

   • Correct:

     ANSWER_TO_THE_QUESTION_OF_LIFE

Coding Style

Overview

1. Function declaration:

   function checkForTraps(dexterity, level) {
       // Do stuff to check for traps here
   }

2. If statements:

   if (gotInitiative) {
       attackDragon();
   }
   else if (speaksDragon) {
       tryNegotiating();
   }
   else {
       runAway();
   }

3. For statements:

   for (var i = 0; i < guards.length; i++) {
       rollTwentySided(guards[i]);
   }

4. While statements:

   while (charactersInjured) {
       castCureLightWounds();
       charactersInjured = checkCharacterHealth();
   }

5. Switch statements:

   switch (characterClass) {
       case 'ranger':
           // Ranger special stuff here
           // Fallthrough
       case 'fighter':
           // Do fighter stuff
           break;
       case 'magicUser':
           // Do mage-specific stuff
           break;
       default:
          // do nothing
   }

6. Try-catch-finally statements:

   try {
       pickPocket();
   }
   catch(e) {
       lookInconspicuous();
       reportBack(e);
   }
   finally {
       runLikeHell();
   }

1. Object literal:

   var obj = {
       spellName: 'Invisible Stalker',
       numberOfFighters: 3,
       checkForTraps = function() {
           // Do trap checking
       } 
   }
   
   var obj = { staff: 'Staff of the Magi', wand: 
       'Wand of Negation', misc: 'Boots of Elvenkind' }
   

Notes

1. If-else statements (also while, et al) MAY be written on a single line, but MUST use brackets.
   • Incorrect:

     if (isUndead) grabFire();

   • Correct:

     if (isUndead) { grabFire(); }

2. Parenthesis in conditional statements (if, while, for, etc.) SHOULD have a space before them.
   • Incorrect:

     if(isNpc) { 
         ignoreTalk(); 
     }

   • Correct:

     if (isNpc) { 
         ignoreTalk(); 
     }

3. Parenthesis in function declarations SHOULD NOT have a space before them.
   • Incorrect:

     function getArmorClass (armorType, dexterity) {
         // Get AC stuff here
     }

   • Correct:

     function getArmorClass(armorType, dexterity) {
         // Get AC stuff here
     }

4. Commas SHOULD be followed by spaces.
   • Incorrect:

     getExperiencePoints(monster,hitPoints);

   • Correct:

     getExperiencePoints(monster, hitPoints);

5. The colon in object literal notation SHOULD have no space in front of it, and be followed by a single space.
   • Incorrect:

     var newCharacter = {
         race:'gnome',
         class:'figheter'
         isNpc:false;
     }

   • Also incorrect:

     var newCharacter = {
         race : 'gnome',
         class : 'figheter'
         isNpc : false;
     }

   • Correct:

     var newCharacter = {
         race: 'gnome',
         class: 'figheter'
         isNpc: false;
     }

6. The conditional operator (?) and the colon used with it SHOULD both have a space before and after.
   • Incorrect:

     var message = speaksDrow? getMessageinDrow():'You do not speak Drow.'

   • Correct:

     var message = speaksDrow ? getMessageinDrow() : 'You do not speak Drow.'

7. Lengthy DOM element IDs or other string parameters SHOULD be placed into variables before using.
   • Incorrect:

     var elem = document.getElementById('charClass-' + charClass + 
         + '_combatStats-' + armorClass + '-' + toHitBonus);

   • Correct:

     var char = 'charClass-' + charClass;
     var combat = 'combatStatus-' + armorClass + '-' + toHitBonus;
     var elem = document.getElementById(char + '_' + combat);