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View for New Pages

Name: View for New Pages
Uploaded: 2016-10-07T14:25:29-04:00
Duration: 342 s
Description: We have the /pages/new path routed to the PagesController's new method. In that method, we've set up a new Page object in the @page instance variable. Now, we need to set up an ERB view template that creates a form based on that Page object.

5:42 with Jay McGavren

We have the /pages/new path routed to the PagesController's new method. In that method, we've set up a new Page object in the @page instance variable. Now, we need to set up an ERB view template that creates a form based on that Page object.

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The form_for method takes a model object, and generates an HTML form for it.

# This will embed the form HTML in the output.
# Here, a form will be generated for the object
# in @page.
<%= form_for(@page) do |f| %>
  <div class="field">
    # This will output a label for the "title" field.
    <%= f.label :title %>
    # This will output a text field used to set the
    # title attribute of the Page object.
    <%= f.text_field :title %>
  </div>

  <div class="field">
    # This will output a label for the "body" field.
    <%= f.label :body %>
    # This will output a larger text field used to set the
    # body attribute of the Page object.
    <%= f.text_area :body %>
  </div>

  <div>
    # Outputs a button used to submit the form.
    <%= f.submit %>
  </div>
<% end %>

You can read more about form_for in the official Rails documentation.

Want to learn more about HTML forms? Check out our course on the topic.

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We have the slash pages slash new path routed to the PagesController's new 0:00

method. In that method we've set up a new page object in the page instance variable. 0:04

Now we need to set up an ERB view template that creates a form based on that page 0:10

object. Some knowledge of HTML forms will be helpful at this point. 0:15

If you haven't worked with forms before, be sure to check out the teacher's notes. 0:19

Since our action is on the PagesController, our view template needs to be 0:23

in the app views pages directory. 0:27

And since the action is named new we should name our template file 0:31

new.html.erb. 0:35

Again, make sure it's all lowercase and watch out for typos. 0:38

We'll start with an output embedding tag with a call to the form_for 0:42

method. form_for takes an argument which is the object we'll be creating a form for. 0:46

The method also takes a block. Everything within the block 0:51

becomes part of the form HTML. 0:54

The finished HTML gets returned from the form_for method. 0:58

That's why we're using an output embedding tag. 1:02

We want to embed the form HTML in the page. 1:04

form_for passes an object representing the form to the block. 1:07

Which we store in the f parameter. 1:11

As usual we need a regular embedding tag down here on a separate line 1:13

with the end keyword to end the block. 1:17

Within the form we create an HTML div element with the CSS class of field 1:20

to hold each form field. 1:25

So div class equals field. 1:27

And then close the div tag. 1:30

We won't review using CSS in rails until a later course. 1:35

But this just applies an existing style that formats things a bit more neatly. 1:39

First, we're going to add a field for the page's title attribute. 1:43

Within the div, we'll add an output embedding tag 1:46

with a call to the text field method on the form object. 1:50

So, f.text_field. 1:53

We'll pass it the ruby symbol title so 1:55

that it's treated as a field for the title. 1:59

Let's save this and 2:01

reload the slash pages slash new path in our browser to see what we've done so far. 2:02

There's our text field. 2:07

If we open our browser's developer tools we can see the resulting HTML. 2:09

It's an input element with a type of text nested within a form element. 2:14

Our users won't be able to tell what this box in the middle of the page is supposed 2:19

to do though. 2:23

Let's add a label to the field so they know to enter a title. 2:24

Just before the embed tag with the text field call. 2:27

We'll add another embed tag with a call to the label method. 2:30

So we'll take the form object and call the label method on it. 2:36

Label needs to receive the same symbol as the text field so 2:40

that it's treated as a label for that field. 2:44

So the text field has a symbol of title and we'll use the same for the label. 2:46

If we reload our browser. 2:53

We'll see the title label before the text field. 2:55

This is an actual HTML label element linked to the title field. 2:58

So if we click on the label, the cursor will focus on the matching field. 3:02

Let's go back and add the remaining form fields, and 3:08

then a button to submit the form. 3:10

For the body attribute, we'll copy the code for 3:12

the title field, but change the symbols to body. 3:14

We'll also change the text field method call to text area to give the user 3:24

a little more room to type in. 3:28

For the slug attribute we'll just copy the title code again and 3:30

change the symbols to slug. 3:34

If we save our work and 3:40

reload the browser we'll see three fields each with a matching label. 3:41

Now we need a button that lets users submit the form. 3:48

We'll create another div to hold the button, but 3:51

we won't worry about applying a CSS class to this one. 3:54

To output the button HTML, 3:58

we'll add an output tag with a call to the form's submit method. 4:00

There's no parameters or anything to add for the submit method. 4:07

If we reload the page we'll see all of our form fields and the submit button. 4:11

Right now we have to manually type in the slash page's new path to get to this form. 4:16

Let's fix that really quick. 4:21

First, let's set up a new page path helper method to make linking to the form easier 4:23

In routes that dot rb, at the end of the slash pages slash new row add as: 4:27

'new_page'. 4:34

Be sure to save that then in app views pages index.html. 4:37

or be in the index of all pages. 4:42

We use an output ERB tag, 4:46

with a call to link_to, to generate a link to create a new post. 4:48

We'll set the link text to new page. 4:52

And call new page path to get the link path. 4:57

Save that, 5:02

and now if we visit the index of all pages, And 5:03

click the new page link we'll be taken to the new page form. 5:07

Let's try fill in the form out now. 5:12

We'll give it create a new page with the title of My Bio. 5:14

I'm a Treehouse teacher. 5:19

And we'll give it a slug just 'bio', but when we submit the form, 5:25

we'll see an error. 5:29

No route matches POST/pages. 5:31

This brings us to the second major part of setting up our form, 5:34

adding a controller action to handle the form submission. 5:37

We'll start on that next. 5:40

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