In order to implement Ember.js templates, you will need to follow a few steps. First, ensure that you have the Ember.js framework installed and set up in your project. Once you have done that, you can proceed with creating or modifying your templates.
Ember.js uses a concept called "Handlebars" for templating. Handlebars is a templating language that allows you to define the structure and dynamic content of your web application's user interface.
To create a new template, you will need to create a new Handlebars (.hbs) file. This file will contain the HTML structure of your template, along with any dynamic variables or expressions that you want to include.
Within your Handlebars template, you can use double curly braces {{}} to enclose any variables or expressions that you want to display dynamically. These variables can be taken from your Ember.js models or controllers.
You can also use various built-in helpers provided by Ember.js to further enhance your templates. These helpers allow you to perform transformations or calculations on your data, conditionally render elements, loop over collections, and more.
Once you have defined your template, you can include it in your Ember.js application by associating it with a route or a component. In the case of a route, you will need to define a template property in your route file and specify the name of your Handlebars template. Similarly, for components, you can set the 'layout' property to the name of your template.
Ember.js follows a convention over configuration approach, so it is important to ensure that your template and associated route or component follow the correct naming conventions to avoid any issues.
By implementing templates in Ember.js, you can easily create reusable components, organize your application's user interface, and display dynamic data in a structured manner.
What is the Ember.js template-only component?
The Ember.js template-only component is a type of component in the Ember.js framework that only consists of a template without any associated JavaScript or actions. It is a lightweight way to define reusable templates without the need for a full-fledged component with all the associated logic. Template-only components can be useful for creating simple, stateless UI components like buttons, icons, or placeholders. They can also be composed together with other components to create more complex UI structures.
How to use conditionals in Ember.js templates?
In Ember.js templates, conditionals can be used to control the rendering of certain parts of the template based on a condition. There are multiple ways to use conditionals in Ember.js templates:
- Using if block:
The if block helper allows you to conditionally render a block of content. It evaluates the provided condition and renders the block if the condition is truthy. Here's an example:
{{#if condition}}
This will be rendered if the condition is true.
{{else}}This will be rendered if the condition is false.
{{/if}} - Using unless block:
The unless block helper is the opposite of the if block helper. It renders the block if the provided condition is falsy. Here's an example:
{{#unless condition}}
This will be rendered if the condition is false.
{{else}}This will be rendered if the condition is true.
{{/unless}} - Using inline conditionals:
You can also use inline conditionals with the if helper. This allows you to render content inline based on a condition. Here's an example:
{{if condition "Rendered if condition is true" "Rendered if condition is false"}}
All of these conditionals can be used with any valid JavaScript or Ember.js expression. They can also be combined with other helper functions or components to handle more complex scenarios.
How to pass data to an Ember.js template?
There are multiple ways to pass data to an Ember.js template. Here are a few common methods:
- Route Model: In an Ember route, you can define a model hook that returns the data you want to pass to the template. For example:
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// app/routes/my-route.js import Route from '@ember/routing/route'; export default class MyRoute extends Route { model() { return { name: 'John', age: 25 }; } } |
Then, in the corresponding template (app/templates/my-route.hbs
), you can access the data using the model
keyword:
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{{model.name}} is {{model.age}} years old.
|
- Controller: You can also pass data to a template via a controller. In this approach, you define a controller associated with the route and set its model property to the data you want to pass. For example:
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// app/routes/my-route.js import Route from '@ember/routing/route'; export default class MyRoute extends Route { } // app/controllers/my-route.js import Controller from '@ember/controller'; export default class MyController extends Controller { model = { name: 'John', age: 25 }; } |
In the template (app/templates/my-route.hbs
), you can access the data directly:
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{{model.name}} is {{model.age}} years old.
|
- Component: If you want to pass data to a specific component within a template, you can use component helpers. For example:
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{{my-component name="John" age=25}}
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In the component's template (app/templates/components/my-component.hbs
), you can access the passed data using component properties:
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{{name}} is {{age}} years old.
|
These are some of the ways you can pass data to an Ember.js template. The choice depends on the specific requirements and structure of your application.
How to pass parameters to a template helper in Ember.js?
To pass parameters to a template helper in Ember.js, you can use the {{helperName parameter1 parameter2 ...}}
syntax.
Here's an example of how to pass parameters to a template helper:
- Define your helper function in app/helpers directory, for example in a file named my-helper.js:
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import { helper } from '@ember/component/helper'; export function myHelper(params/*, hash*/) { // Access the parameters here let param1 = params[0]; let param2 = params[1]; // Do something with the parameters return result; } export default helper(myHelper); |
- In your template, you can use the my-helper helper and pass the desired parameters:
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{{my-helper "parameter1" 42}}
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In this example, "parameter1"
and 42
are passed as parameters to the my-helper
helper. Note that the parameters are separated by spaces when calling the helper.
You can access these parameters in the helper function using the params
array. In the example above, params[0]
will contain "parameter1"
and params[1]
will contain 42
.
What are the built-in helpers in Ember.js templates?
Ember.js provides several built-in helpers in its templates. Some of the commonly used ones include:
- {{if}}: It allows conditional rendering of a block based on a provided condition. If the condition evaluates to true, the block is rendered; otherwise, it is skipped.
- {{each}}: It iterates over a collection and renders a block for each item. It also binds each item to a context variable that can be used within the block.
- {{unless}}: It is the opposite of the {{if}} helper. If the condition evaluates to false, the block is rendered; otherwise, it is skipped.
- {{with}}: It sets a new context within a block. The block will have access to the provided context object and any properties within it.
- {{bind}}: It creates a two-way binding between an input field and a property. Any changes made in the input field will be reflected in the associated property, and vice versa.
- {{action}}: It triggers a specified action when a user interacts with an element, such as clicking a button. Actions can be defined in the associated controller or component.
- {{partial}}: It renders a partial template within the current template. Partial templates can be reused across different templates.
- {{yield}}: It defines a placeholder within a component template. It allows the component to render its children when used in a block form.
These are just a few examples of the built-in helpers available in Ember.js templates. There are many more helpers provided by Ember.js and additional ones can be created using custom helpers.
How to extend a template from a parent template in Ember.js?
To extend a template from a parent template in Ember.js, you can use the {{partial}}
helper or the {{yield}}
helper.
- Using the {{partial}} helper:
Inside the child template, use the {{partial}} helper to include the parent template.
Example:
{{!-- parentTemplate.hbs --}}
This is the parent template
{{outlet}} {{!-- childTemplate.hbs --}} {{partial "parentTemplate"}}This is the child template
This approach will insert the content of the parent template into the child template. - Using the {{yield}} helper:
Inside the parent template, wrap the specific content that you want to extend in the {{yield}} helper.
Inside the child template, use the {{yield}} helper to render the content from the parent template.
Example:
{{!-- parentTemplate.hbs --}}
This is the parent template
{{yield}} {{!-- childTemplate.hbs --}} {{#each model as |item|}} {{#parentTemplate}}{{item}}
{{/parentTemplate}} {{/each}} This approach allows you to inject specific content into the parent template.
Both approaches can be used to extend a template from a parent template in Ember.js. Choose the one that best suits your requirements.