Rails template erb

A very inefficient way to display a list of users would be building a view like the following one:. Imagine there are not 10 users but thousands of them. The code inside the comment tags gets ignored at the moment of building the template. Let me tell you something great: Mastering erb will be a matter of minutes if you are already good with Ruby and HTML. Otherwise, It will be a matter of hours practicing until you get it. If you plan to become a professional Rails developer, you will practice this skill a lot, so don't worry.

You will master it sooner or later. Important: Avoid using logic heavy erb code in your views. For those cases, it is always better to create a helper method to deal with that. Please follow me on Twitter and connect on LinkedIn.

Text outside a tag becomes literal text, but it is subject to any tagged Ruby code surrounding it. For example, text surrounded by a tagged if statement only appears in the output if the condition is true. An expression-printing tag inserts values into the output. You can trim line breaks after expression-printing tags by adding a hyphen to the closing tag delimiter. Non-printing tags that contain iterative or conditional expressions can affect the untagged text they surround.

You can trim whitespace surrounding a non-printing tag by adding hyphens - to the tag delimiters. The first literal tag is taken, and the rest of the line is treated as a literal. This is the main source of data for templates. An ERB template has its own local scope , and its parent scope is set to the class or defined type that evaluates the template.

Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually. Linked 0. Related Hot Network Questions. Question feed. A tag with an equals sign indicates that enclosed code is an expression , and that the renderer should substitute the code element with the result of the code as a string when it renders the template.

Use an expression to embed a line of code into the template, or to display the contents of a variable:. Tags without the equals sign denote that the enclosed code is a scriptlet. Each scriptlet is caught and executed, and the final result of the code is then injected in to the output at the point of the scriptlet.

Notice that the scriptlets in this example enclose an expression. The scriptlets produce no text themselves, but cause the enclosed expression to run multiple times, and the result of the expression is written to the output each time. By default, a newline character is added to the page after the position of each tag. To suppress this newline, use the optional parameter of ERB. Rails extends ERB, so that you can suppress the newline simply by adding a trailing hyphen to tags in Rails templates:.

A file that contains an ERB template may have any name, but it is the convention that the name of file should end with the.

Rails requires template files to have the extension of the output type, followed by. Some applications use the extension.