The goal of Comm Lab Web is to develop creative web applications.
#Posting your HW
If you miss more then 1 assignment you will not pass!
- Intro to Sinatra (up to “Hello Worlds: What is a route?)
- Is HTML a programming language?
- Introduction and software we’ll use in this class
- Map of interaction: User to Client, over Network, to Server, to Datastore, and back.
- Web / HTTP
- Basics of client/server/datastore interaction
- Using the web to allow access to remote resources, to respond to multiple clients, to apply conditional logic, to persist data, to accumulate data.
- HTTP Requests
- Examples of clients
-
Intro to HTML
- Tags that open and close
- Mark up content
- Nested tags
- Basic Html Example
-
Tags
<html>, <title>, <body>, <em>, <strong>, <h1-h5>, <a>, <img>, <ol>, <ul>, <p>- Introduce
<form>and<input>types
- Your Sinatra folder
- Simple Sinatra script
- Simple HTML form example in Sinatra
You've got a great idea for the next big thing: it's called Etzy, and it's a place to sell artwork online. You want to drum up interest and get some visitor feedback, so you decide to create a signup form!
For this assignment you must create a page where a visitor can input his or her name and email, and some preferences. We're not worried about doing anything with the form data right now, or even making it pretty. Just focus on getting the markup complete.
The page should include the following:
- a heading for the name of the business
- a sentence describing what it does
- a text input for a name
- a text input for an email address
- a checkbox for receiving an email newsletter
- a dropdown menu for "How you heard about us" ("google", "from a friend", "online ad", etc.)
- a radio button group for choosing a role ("buyer", "seller", or "both")
You should also create a 3 page site with a Home (which can be your form) and 2 other links with text and image
- Name
- Small back story
- Dropdown menu for "Weapon choice" (“Sword”, “Ax”, “Wand”)
- A radio button group for choosing a role ("Male", "Female", or "Ambiguous")
- Check boxes “What to carry:” (“Potions”, “Food”, “etc”)
Most text adventures operate in the following: Your character enters a room and is able to investigate. Your investigations leads to consequences. Click on the link for an example
- Read WHATWG: Forms
- If you're stuck, look at this basic form example for guidance.
We will also start looking at Ruby and Sinatra this week too, so we can start building a backend for our signup form.
- Complete levels 1 - 3 of the Try Ruby tutorial - optional
- Read Intro to Sinatra to “Hello Worlds: What is a route?"
Sinatra Up and Running, p. 15-21 (It’s not much, so please read it thoroughly)
- HTML basics
- Class Homework
- Open Terminal (Putty for Windows)
- run
ssh [email protected]. Remember to put in your netid instead of “netid” - Type in your password when prompted
- run
ruby /etc/new_sinatra_app.rb nameofapp. Remember to replace “nameofapp” with the name of your application. - Go to your blank Sinatra app here (using your netid and the name of your app):http://itp.nyu.edu/ ~ netID /sinatra/ nameofapp
-
Ruby
- General (no types, etc)
- Syntax
- Variables
- Functions
- Loops
- Gems
- Render HTML with Sinatra
- Send to route in Sinatra
The components of a for have 2 parts, the form tag and the body
<input type="text" name="name" ></input>
-
Form Tag
- Action - Route where the form data will be processed
- Method - Which Http request protocol to use
-
Body - Form inputs
- type - The method of input
- name - The reference for the value
- value - The user input selection or text
Sinatra works by declaring routes. Routes are the URLs associated with your application. A simple route looks like this:
get '/home' do
"Code goes in here"
end
Think of routes as litte programs that are going to run when you you visit the link. The route is composed of 2 imporant parts the method and the link.
Methods include: GET, POST, DELETE, PUT, etc. After the method you declare the link. In class, we mostly use GET and POST.
GET - Requests data from a specified resource POST - Submits data to be processed to a specified resource
GET requests can be used in routes that: * Serve up content * Process form * Form data public * The form data is sent in the URL in name and value pairs
POST requests can be used in routes that: * Process form * Form data private * Information is sent in the HTTP message body
For more differences visit click here.
What about the form data?
Sinatra uses a global variable called parameters. The syntax for parameters is params[:name]. The :name is the reference name pulled from the form. Parameters can also be pulled from a url route. When used in a route /home/:name , this can be referenced by params[:name]
This is an example for taking in a value from a form:
post '/home' do
name = params[:name]
end
This is an example for taking in a value from a url
get '/home/:name' do
name = params[:name]
end
When we want to output variables from sinatra from our route:
post '/home' do
name = params[:name]
"This is my name #{name}"
end
When we want to output variables from sinatra to our erb:
The @ symbol is use to signify that the variable can be accessed from the erb template
app.rb
post '/home' do
@name = params[:name]
erb :name
end
name.erb
<p><%=@name%></p>
You can run ruby code in your erb.
name.erb <% name = "zeven" %>
My name is <%=name%>
This will output the HTML code:
<p>My name is zeven</p>
The <% %> escape characters are used to write ruby code:
<% name = "zeven" %>
This will not output anything in your template
To output variables to your template:
The sinatra reads the = sign and understands to render the variable
<%=variable%>
Create a new Sinatra application on the ITP Server. Create a GET “/form” route that returns an HTML form with a few different input types. Create a POST “/form” route that reads these parameters and sends back a dynamic HTML page. This HTML page should at least have an image that changes depending on the input from the form.
###Putting images into your app directory.
You need to make a folder called public. Inside of that make a folder called images and place your images there. Double click into your app folder. Right click and add new folder. Type public. Double click to go into the new public folder you created. Right click and add new folder called images. Put your images in there. You should put the full path to your file in the image src. It will look something like this:
<img src="http://itp.nyu.edu/~YOURNETID/sinatra/YOURAPP/public/images/penguin.jpeg"/>
If your image does not appear there could be another issue with permissions. Right click on your public folder you just created and select info. Click on the permissions tab. Where it says unix permissions type 755 and click apply changes recursively.
An Introduction to Datamapper - (Skip “Installing” part)
- Simplest model: a database can be a file
- Read and write to a file as a simple model of persistence
- YAML
- Datamapper is a library that enables you to save to a database in Sinatra
- Setup Datamapper
- Write your Datamapper class
- Properties: Serial, Boolean, String, Text, Float, Integer, Datetime,
First you need to add the library:
require 'dm-core'
Second add the basic database setup:
DataMapper::setup(:default, {:adapter =>'yaml', :path => 'db'})
We are using a yaml database saved to the path db
The Class is what Datamapper uses to create the database model
class BlogPost
include DataMapper::Resource #This line makes sure Datamapper uses this class to build our database structure
property :id, Serial #We always need a Serial property. This ensures every new data entry has a unique number attributed with it. property :title, String property :body, Text
end
Asking for entry based on the Serial property. This returns a single entry
@entry = BlogPost.get(params[:id])
To access the data you use the instance name @entry followed by a . and the name of the property you want to access i.e. @entry.title, will return the title of your current query
Asking for all entries in the database. This returns an array of objects
@allEntries = BlogPost.all
To display the data in your erb you need to loop through an array:
<%@allEntries.each do |content|%>
<%=content.id%>
</br>
<%=content.title%>
</br>
<%=content.body%>
</br>
<%end%>
- Example of form + save
- Returning User Example
- Advanced Returning User Example
- Company Structure Example
Write a sinatra app that shows a user form, and on the POST request recognize whether the user is returning.
Sinatra Up and Running, p. 21-30
- Conditional programming
- Create a mini-website with a menu and a couple of pages. All HTML has to exist in .erb views, and some of the actual data has to be retrieved and outputted from Datamapper.
- Start planning your final project. Be prepared to talk about your idea next class.
Look at theDatamapper Documentation . See if you can find features that you can use.
What do you want to do? What is preventing you from doing it?
- Birthday Registration Example
- More Datatypes
- Serial
- String
- Boolean
- Integer
- DateTime
- Example of all of these
- Datatype options
- Required
- Default
- Length
- Finding Records
- first
- all
- first_or_new
- Conditions (gt, lt, gte, lte, not, eql, like)
- Ordering (desc, asc)
- Counting
- Start developing your final project.
- Example of a big final project
-
loadStrings to your app
-
Making calls from HTTProcessing
-
Other file formats (XML and JSON)
Calling your site with a Ruby script on your machine
If we have time, let’s use other people’s APIs.
Let’s present your sites!