Complete Magento2 Theme Development ( HTML to Magento2 Theme )

Source: http://unitedwebsoft.in/blog/complete-magento2-theme-development-html-to-magento2-theme/

Magento 2.0 Has a different theme structure than Magento 1.x. Like Magento Module ,Magento 2.0 it must have a Namespace/Vendor name to create a theme. Lets take a look app/design/frontend in the folder we will find a folder Name Magento which is the vendor name. Now we will create our theme in our Vendor Name. Lets create a directory name 'United' which is our vendor name under 'app/design/frontend'. under the 'United' directory create the theme that you want . lets create our theme name 'mytheme'. So, we will create our theme 'mytheme' under 'United' directory. Under 'mytheme' directory we will create theme.xml, registration.php, comopser.json, web and media directory. So, our theme folder structure will same as following.

app/design/frontend/United/mytheme/
—-theme.xml
—-web
—-etc
—-registration.php
—-composer.json
—-media

Lets describe the theme structure. If you see the root directory there is no 'skin' folder. so the web directory will work as 'skin' where we will place css,js,images folders. lets open the theme.xml and add the following code

    
    Magento/blank
    
        media/preview.jpg
    

 
 

Lets describe the code . 'title' tag is the title of our new theme and the parent them will play as base them in magento 1.x. if we go pub/static/frontend/Magento we will find a folder name blank which we will use as our parents theme. (note : if not located on above folder do find under vendor/magento/theme-frontend-blank) The new feature of Magento 2.0 is we can use any theme as our parents theme. after complete the theme mytheme we can create our another them mytheme2 using mytheme as a parents. add a preview.jpg image in media directory for theme preview. Now in the compser.json file we will add the following code.

{
    "name": "magento/mytheme",
    "description": "N/A",
    "require": {
        "php": "~5.5.0|~5.6.0|~7.0.0",
        "magento/theme-frontend-blank": "100.0.*",
        "magento/framework": "100.0.*"
    },
    "type": "magento2-theme",
    "version": "100.0.2",
    "license": [
        "OSL-3.0",
        "AFL-3.0"
    ],
    "autoload": {
        "files": [
            "registration.php"
        ]
    }
}

Now in the registration.php file we will add the following code.

This will register your theme in the system. so the theme.xml and registration.php will be the main file of your theme. In etc forder you can add a view.xml copy form pub/static/frontend/Magento/blank folder. (or if not found there vendor/magento/theme-frontend-blank) it has some interesting setting.
Now create 'images' folder inside 'web' folder
Example: /app/design/frontend/United/mytheme/web/images/ Add a logo image to the theme: you need a '.svg' extension file name of logo , to convert your logo use any online tool ex: https://convertio.co/png-svg/ Now put your logo.svg file ex: /app/design/frontend/United/mytheme/web/images/logo.svg
Clear the cache from magneto admin panel. Then From STORE->Configuration->Design section we will find out our theme 'mytheme' .

Select it from dropdown and save the settings. If any issue with static content deply , follow below steps

Command to deploy static files :

php -f magento setup:static-content:deploy note : right click /bin then select 'Open command window here' , before using command ,you must have already installed composer in your system. If you have not installed composer ,download from here https://getcomposer.org/Composer-Setup.exe (for windows) Now you are with your new theme mytheme !!!!.

Add our custom css file

(ref. include css : http://devdocs.magento.com/guides/v2.0/frontend-dev-guide/css-topics/css-themes.html) Copy folder 'Magento_Theme' from 'vendor\magento\theme-frontend-blank\' to your theme folder example path :app\design\frontend\United\mytheme\Magento_Theme Remove 'web' folder from 'Magento_Theme' folder . Now open 'default_head_blocks.xml' found under app\design\frontend\United\mytheme\Magento_Theme\layout and add below code to section So after adding it looks like

Now, Create 'css' folder inside \app\design\frontend\United\mytheme\web After create a file 'customtheme.css' in the 'css' folder example path :\app\design\frontend\United\mytheme\web\css\customtheme.css then put required css ex:

.page-wrapper {
  background-color: #333;
}
 
 

Now, Refresh your cache from admin->config ( ir required deply static content from command line as described above .)

 

Now , it will show new background color . note : If you editing your css example inside \app\design\frontend\United\mytheme\web\css\customtheme.css, delete 2 folders 1) 'static' folder found under 'pub/' 2) 'cache' folder found under 'var/'

Understand how magento templates,layout loads

1st default template file is vendor\magento\module-theme\view\base\templates\root.phtml magento 2 builds html structure from xml files next important file to build page-wrapper, columns is vendor\magento\module-theme\view\base\page_layout\empty.xml Then it loads files from below folder according to page request vendor\magento\module-theme\view\frontend\page_layout

Customizing layout for our theme

Copy folder 'page_layout' from vendor\magento\module-theme\view\frontend to app\design\frontend\United\mytheme\Magento_Theme Now, if you need to add our own div with class or id ,we have to declare inside files of app\design\frontend\United\mytheme\Magento_Theme\page_layout example inside these files :

1column.xml 
2columns-left.xml
2columns-right.xml
3columns.xml

ref. http://devdocs.magento.com/guides/v2.0/frontend-dev-guide/layouts/layout-extend.html ( Note : you must clear your cache , put some block inside containers from admin Content->widget . Consider if you editing previously created widget ,it does not work because it created for another theme . So do create new widget by selecting our current theme . ) Also customize global containers/blocks of our theme inside default.xml located under app\design\frontend\United\mytheme\Magento_Theme\layout\ create global container (for all pages ) ex: So, files looks quite similar below

......
   
        
			
			
..........
..........
 

HTML to Magento Theme

• Copy your css files code to the file created in previous step i.e customtheme.css in our example inside app\design\frontend\United\mytheme\web\css
• Copy your HTML template's images to app\design\frontend\United\mytheme\web\images
• Start customizing files located under app\design\frontend\United\mytheme\Magento_Theme according to our HTML's template div, class requirements . Here we have to add,alter containers or blocks in these files . Explained in above steps of 'Customizing layout for our theme' .

That's it initially it took long steps but just for the first time. If you want to create another theme having some experience , it doesn't take too much time . Feel free to put below any comments ,I will try to reply soon .