# The Odin Project
## How to ask good programming questions
- Be very specific and patient
- use screenshots when available
- ask questions directly instead of asking to ask ie. "are there any java experts around?"

## Git
### Set up Git
- Set username and email
```
git config --global user.name "username"
git config --global user.email "email"
```
- If using GitHub, change branch from 'master' to 'main'
```
git config --global init.defaultBranch main
```
- Enable colorful output with git
```
git config --global color.ui auto
```
- Set default branch reconciliation behavior to merging 
```
git config --global pull.rebase false
```
- Verify the config
```
git config --get user.name
git config --get user.email
```
### Create an SSH Key for repos
- SSH keys are good for avoiding retyping credentials every time
    - Check to see if there is an existing ssh key
```
ls ~/.ssh/id_ed25519.pub
```
    - if nothing appears, then there is no key and one needs to be made
- Create ssh key
```
ssh-keygen -t ed25519 -C <youremail>
```
- press enter when asked for what location to store it unless you have a specific location
- add a passphrase and retype it
### Link SSH key to Git
- Find the ssh key input on GitHub or repository website of your choice
- Click on new ssh key and give it a name and leave the window open for the next steps
- Copy the public SSH key
```
cat ~/.ssh/id_ed25519.pub
```
- Paste the key into your settings, it should start with ```ssh-ed25519``` and end with your email
### Change git repository remote
```
git remote set-url origin https://'username':'password'@repositorylink
```
### Using Git
- Check git version by using `git --version`
- After creating a new repository you can clone it to your current directory by using ``` git clone <repolink>```
- After the cloning, check the url with ```git remote -v``` 
- Use ```git status``` to check the status of the current files within your directory
- To commit to the repo you can use ```git commit -m "Add helloworld.txt"```
- Confirm with ```git status```
- You can use ```git log``` to view the most recent commits
- After creating a file you can use ```git add <filename>``` to add that specific file or ```git add .``` to add all files within the directory that are not on the repo
- We can push the changes to the cloud repository with ```git push origin main```, origin being the remote location and *main* being the branch to upload to
  - Make sure to only push working code
#### Git Best Practices
- Atomic commits
  - A commit that includes changes related to only one feature or task of your program.
    - Easily reversible if the commit causes breaking changes
    - Enables you to write more specific commit messages
#### Changing the Git Commit Message Editor
- Typing ```git config --global core.editor "code --wait"``` into the terminal will give you the option to use either ```git commit -m <your message here>``` or ```git commit``` without anything extra.
#### When to Commit
- These are best made when you think is a good time to take a **snapshot** of your current project
- Never commit code that isn't working to the main branch if it was working before
- It is considered best practice to commit every time you have a meaningful change in the code
  - Creates a trail to show how you got to the current iteration of the code
- Useful for when looking back to when the project feature was working to compare what you've changed

## HTML And CSS Introduction
- What is HTML?
  - Stands for **Hypertext Markup Language**
  - It's the raw data that a webpage is built out of. Includes:
    - text
    - links
    - cards
    - lists
    - buttons
- What is CSS?
  - Stands for **Cascading Style Sheets**
  - It's the styling of the HTML page
    - Controls colors
    - Controls Positioning of text and font
- HTML and CSS are ***not*** programming languages, technically speaking because they only present information and are not used to compute any logic
- JavaScript would be a programming language that leverages both HTML and CSS
### [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Element) and Tags
- HTML defines the structure and content of webpages.
- HTML elements are used to create:
  - paragraphs
  - headings
  - lists
  - images
  - links
- Elements are simply pieces of content wrapped in opening and closing tags
  - Another way to define them is *containers for content*
  - Paragraph is `<p> </p>`
  -  Some tags do not require a closing tag
   -  line break is `<br>` or `<br />`
   -  image insert would be `<img />` or `<img>`
- There many tags, looking at documentation for most of them is standard [HTML Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Element)
- [Intro to HTML Video 3:42](https://www.youtube.com/watch?v=LGQuIIv2RVA&list=PL4-IK0AVhVjM0xE0K2uZRvsM7LkIhsPT-&ab_channel=KevinPowell)
### HTML Boilerplate
- All HTML docs have the same basic structure that needs to be in place before anything useful can be done.
  - [index.html](/OdinProject/html-boilerplate/index.html)
#### The DOCTYPE
- Every HTML page starts with a doctype declaration
- The purpose of it is to tell the browser what version of HTML it should use to render the document(current being HTML5)
  - HTML5 Doctype is `<!DOCTYPE html>`
- The doctypes for older version of HTML were more complicated
- Example of doctype for HTML4
```
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
```
#### HTML Element
- Now we need to provide an `<html>` element. More commonly known as the *root element* of the document
  - root means that every other element in the document will be a descendant of that one
- The `lang` attribute specifies the language of the text content in that element
  - primarily used for improving accessibility of the webpage
  - `en` is used for English
- The `<head>` element is where important meta-information about our webpages and items required for our webpages to render correctly in the browser
  - inside of the `<head>` element, there should not be any element that displays content on the webpage
#### The Charset Meta Element
  - The meta tag for the charset encoding of the webpage in the head element: `<meta charset="utf-8">`
  - The encoding ensures that the webpage will display special symbols and characters from different languages correctly in the browser
#### Title Element
  - Should go in the head of an HTML doc `<title>My First Webpage</title>`
  - It's used to give webpages a human-readable title which is displayed in our webpages' browser tab
  - The default title for a webpage is it's filename, in this case `index.html`
    - This is a security risk as you wouldn't want the internet to know what any of your files are named or how they are placed within the project directory
    - Also would make it difficult for the end user to remember what tab it is if they have multiple open
```HTML
<!DOCTYPE>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>My First Webpage</title>
    </head>
</html>
```
#### Body Element
- All content will be displayed to users inside of this tag
```HTML
<!DOCTYPE>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>My First Webpage</title>
    </head>

    <body>
    </body>
</html>
```
#### Viewing HTML Files in the Browser
- You can drag and drop an HTML file into the browser and it will open up the page
- You can also use a preview extension that will open a browser window
- In Ubuntu you can use the command `google-chrome index.html` to open it as well
- Using `<h1>` for the heading can render out a title on the page
```HTML
<!DOCTYPE>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>My First Webpage</title>
    </head>

    <body>
        <h1>Hello World!</h1>
    </body>
</html>
```
- **VSCode can generate the entire boilerplate by entering `!` into a blank `.html` document**
### Working With Text
#### Paragraphs
- If text is not preceded by a `<p>`, then it will all clump together as one large body of text
- ![](images/chrome_dnDCL9ylH1.png)
- ![](images/chrome_r0YaBjn2YV.png)
#### Headings
- These use the `<hx>` tag where `x` is the number that changes the font
  - `<h6>` is the smallest font
- ![](images/chrome_drT4PQKjhb.png)
#### Strong Element
- The `<strong>` tag makes text **bold**
- It also marks text as important semantically 
  - This affects tools like screen readers for visual impairments
  - It will change the tone of the voice for the content within the `<strong>` tag
```HTML
<strong>Showing bolded wording</strong>
```
- ![](images/chrome_qSqVJNFNTe.png)
#### Em Element
- The `<em>` tag makes text italic and also emphasises in text to speech
- ![](images/chrome_qzKKOkOr72.png)
#### Nesting and Indentation
- Elements are nested for legibility 
  - Also known as parent/child/sibling elements
  - Similar to braces for code
```HTML
<html>
  <head>
  </head>
  <body>
    <p>Lorem ipsum dolor sit amet.</p>
  </body>
 </html>
 ```
- ![](images/chrome_AhnmdRAmL7.png)
#### HTML Comments
- Comments are not visible when the page is rendered
  - Useful for reading page format when performing maintenance
  - Comments are written with `<!--     -->`, where the comment is inside the whitespace
```HTML
<h1> View the html to see the hidden comments </h1>

<!-- I am a html comment -->

<p>Some paragraph text</p>

<!-- I am another html comment -->
```
- ![](images/chrome_jpELgY8wjN.png)
### Lists
- Lists are one of the most commonly usedd elements/data structures because they neatly organize many items
#### Unordered Lists 
- The order is random or irrelevant, then using an unordered list is the right choice
- It's created by using the `<ul>` tag, with each element inside of the list using the `<li>` tag
```HTML
<ul>
  <li>Item 1</li>
  <li>Item 2</li>
  <li>Item 3</li>
</ul>
```
- ![](images/capture1.png)
#### Ordered Lists
- Useful when the order of the list matters
- It's created by using the `<ol>` tag instead with the same `<li>` elements inside of it
```HTML
<ol>
  <li>Item 1</li>
  <li>Item 2</li>
  <li>Item 3</li>
</ol>
```
- ![](images/capture3.png)
### Links and Images
- Links allow for the chaining of other HTML pages on the web
- Create an `index.html` file and use it so link other pages within the [odin-links-and-images](/OdinProject/odin-links-and-images/index.html) directory
#### Anchor Elements
- The anchor element is denoted by the `<a>` tag
  - It creates a link with a separate page and routes towards it
  - Requires an HTML attribute in order to complete the link
- This link is known as a reference, `<a href="https://www.theodinproject.com/about">click me</a>`
  - the `href` attribute is what highlights text in blue to show that it is linked to an address
  - Links work for anything that has a web address, this includes:
    - photos
    - documents
    - pdfs
    - html pages
    - videos
#### Absolute and Relative Links
- Most links are one of two things:
  - Links to pages on other websites
  - Links to pages on our own website
- Absolute Links
  - Links to pages on other websites, in order to link you need the full address of the destination
    - Example: `protocol://domain/path`, `www.https://youtube.com/home`
- Relative Links
  - Links to other pages within our own website, or internal links
  - These links do not include the domain name since it is within the same domain
  - Relative links consist of the **file path** instead of the web address
- Links are created the same whether absolute or relative, the `href` tag is what controls the anchor binding
- Proper file management recommends to have a separate directory for `pages` within the project
- The proper way to direct an anchor to a subdirectory is by using `./` in the path
  - This tells the anchor to start looking for the **file/directory relative to the `current` directory of where the `index.html` is located** 
#### A Metaphor
- The domain name `town.com` is a city
- The directory where the website is located would be similar to a museum `/museum`
  - Each page on your website could be considered a room, in this case a room within the museum `/museum/movie_room.html` or `/museum/coffee_shop.html`
  - Relative links like `./shop/coffee_shop.html` are directions from the current room (movie_room)
  - Absolute link would be the full directions to the room from entering the town
    - Ex: `https://town.com/museum/shops/coffee_shop.html`
#### Images
- HTML uses the `<img>` tag in order to embedd images into the page, does not require a closing tag
  - These images can be added with Absolute or relative links Ex: `<img src="https://www.theodinproject.com/mstile-310x310.png">`
  - ![](images/capture4.png)
#### Parent Directories
- In order to navigate to the parent directory when linking, you should use `../` relative to the current directory
#### Alt attribute
- images also have an alt attribute
- Used to describe the image, helps with accessability and when the image itself can't be loaded
- Ex: ` <img src="https://www.theodinproject.com/mstile-310x310.png" alt="The Odin Project Logo">`
  - This loads the logo, if it can't then `The Odin Project Logo` is displayed
#### Div
- A `<div>` is a basic HTMl element that intiates an empty container
- Commonly used to pair with css styling for certain portions of the page
### Recipes
- Project to build a basic recipe website
- Will have a main index page with links to a few recipes
#### Assignment
- Iteration 1: Initial Structure
  - Within the `odin-recipes` directory, create an `index.html` file
  - Fill it out with the usual boilerplate HTML and add an `h1` heading "Odin Recipes" to the body
- Iteration 2: Recipe Page
  - Create a new directory within the `odin-recipes` directory and name it `recipes`
  - Create a new HTML file within the `recipes` directory and name it after the recipe it will contain.
    - Ie. `lasagna.html`
    - Include an `h1` heading with the recipe's name as its content
  - Back in the `index.html` file, add a link to the recipe page you just created
    - Use an anchor
- Iteration 3: Recipe Page Content
  - An Image of the finished dish under the `h1` heading
  - Under the image, it should have an appropriately sized "Description" heading followed by a paragraph or two describing the recipe
  - Under the description, add an "Ingredients" heading followed by an **unordered list** of the ingredients needed for the recipe.
  - Finally, under the ingredients list, add a "Steps" heading followed by an **ordered list** of the steps needed for making the dish
- Iteration 4: Add More Recipes
  - Add two more recipes with the identical page structures to the recipe page you've already created
  - Don't forget to link to the new recipes on the index page
    - Consider putting all the links in an *unordered list* so they aren't all on one line.
## CSS Foundations
### Basic Syntax
- Uses semicolons to signify the end of a declaration
- Uses the `property:value` pair format
### Selectors
- These are the HTML elements to which CSS rules apply
#### Universal Selector
- This selects elements of any type and the syntax for it is an asterisk
  - Ex: every element should be in purple
```CSS
  * {
    color: purple;
  }
```
#### Type Selectors
- A type selector is also referred to as an **element selector**
  - Selects all elements of the given element type
```HTML
<!-- index.html -->

<div>Hello, World!</div>
<div>Hello, again!</div>
<p>Hi...</p>
<div>Okay, bye.</div>
```
```CSS
/* styles.css*/

div {
  color: white;
}
```
- All three `<div>` elements would be selected, while the `<p>` would be left alone
#### Class Selectors
- These will select all elements within a given class
- A class is initialized within a `<div>` tag
```HTML
<!-- index.html -->

<div class="alert-text">
  Please agree to our terms of service.
</div>
```
```CSS
/* styles.css*/

.alert-text{
  color: red;
}
```
- The syntax for class selectors uses a **period** before the ***case-sensitive value*** of the class attribute
- Classes can be used multiple times if you want to have them in different areas of the webpage, but with the same styling
- multiple classes can be initialized with a space instead of a comma
  - Ex: `class="alert-text severe-alert"` initializes both the `alert-text` and the `severe-alert` class
#### ID Selectors
- Similar to class selectors, select an element with the given ID instead of the class
```HTML
<!-- index.html -->

<div id="title">My Awesome 90's Page</div>
```
```CSS
/* styles.css*/

#title{
  background-color: red;
}
```
- instead of a period, they use the **hastag** immediately followed the ***case-sensitive value*** of the ID attribute
- ID's should be used sparingly and good use cases for them are:
  - changing something specific within a page
  - links that redirect to a section on the current page
- Major difference between classes and IDs is that an element can only have **one ID**
  - The ID cannot be repeated on a single page, so they are unique per html page
  - The ID should not contain any whitespace at all
#### Grouping Selector
- If two groups share some of their stylings, then you can cut down on the amount of repetittion
```CSS
.read {
  color: white;
  background-color: black;
  /* several unique declarations */
}

.unread {
  color: white;
  background-color: black;
  /* several unique declarations */
}
```
- Both `.read` and `.unread` selectors share the `color: white;` and `background-color: black;` declarations, we can **group them with a comma** to have only the unique declarations be separate
```CSS
.read,
.unread {
  color: white;
  background-color: black;
}

.read {
  /* several unique declarations */
}

.unread {
  /* several unique declarations */
}
```
- The advantage to grouping would be that if we want to ever change the `color` or `background-color`, then we can quickly change them within the single selector for the entire page
#### Chaining Selectors
- Another way to use selectors is to chain them as a list without any separation
- Ex: HTML `<div>` and `<p>` with the `subsection` class
```HTML
<div>
  <div class="subsection header">Latest Posts</div>
  <p class="subsection preview">This is where a preview for a post might go.</p>
</div>
```
- In order to only change the class with both `subsection` and `header`, then we chain the selectors
```CSS
.subsection.header{
  color:red;
}
```
- `subsection.header` selects any element that has both the `subsection` ***and*** `header` classes. 
- Works for all combinations of selectors except for [Type Selectors](#type-selectors)
- Can also be used to chain a class and an ID
```HTML
<div>
  <div class="subsection header">Latest Posts</div>
  <p class="subsection" id="preview">This is where a preview for a post might go.</p>
</div>
```
```CSS
.subsection.header {
  color: red;
}

.subsection#preview {
  color: blue;
}
```
- Notice how a class is chained to an ID by using their respective syntax of `.class#ID`
  - > Note: Does not work for chaining more than one type of selector
  - It is also dependent on the type of element
  - Ex: `<div>` can't be chained to `<p>` because it would create `<divp>` and it doesn't exist as an element
#### Descendant Combinator
- Allows for combining multiple selectors differently than either grouping or chaining them
- Shows the relationship between the selectors
- Four types of combinators
- The **descendant combinator** is represented in CSS by a single space between selectors
  - Will only cause elements that ***match the last selector to be selected if they also have an ancestor***(parent, grandparent, etc) that matches the previous selector
  - Ex: `.ancestor .child` would select an element with the class `child` if it has an ancestor with the class `ancestor`, no matter how deep
```HTML
<!-- index.html -->

<div class="ancestor"> <!-- A -->
  <div class="contents"> <!-- B -->
    <div class="contents"> <!-- C -->
    </div>
  </div>
</div>

<div class="contents"></div> <!-- D -->
```
```CSS
/* styles.css */

.ancestor .contents {
  /* some declarations */
}
```
- In this example only **B and C** will be selected because they are part of the `ancestor` class
  - D is off on its own without the `ancestor` parent <div>
- There is no limit to the amount of combinators that could be used
  - `.one .two .three .four` would be **valid**, but would only select the elements that contain the class `four` if it has an ancestor of `three` and if that has an ancestor of `two` and continues if it is all within the ancestor of `one`
#### Properties to Get Started With
- Color and Background-Color
  - The `color` property sets an element's text color, while `background-color` sets the background color of an element
  - Both properties can accept one of several kinds of values, here is a link for all [legal values](https://www.w3schools.com/cssref/css_colors_legal.php)
    - Common value is a **keyword** such as an actual color name like `blue` or `transparent`
    - Also accepts **Hex, RGB, and HSL** values like `#4f4f4f` 
```CSS
p {
  /* hex example: */
  color: #1100ff;
  /* rgb example: */
  color: rgb(100, 0, 127);
  /* hsl example: */
  color: hsl(15, 82%, 56%);
}
```
#### Typography Basics and Text-Align
- `font-family` can be a single value or a comma-separated list of values that determine what fron an element uses
  - A font name like `"DejaVu Sans"`(quotes are used for the whitespace between the words) or a generic font like `sans-serif`
- Browsers will go through the font list until it finds one that it can display and has access to
  - Ex: `font-family: "DejaVu Sans", sans-serif;`
  - The browser will attempt to display `"DejaVu Sans"`, if not found then it will fallback to `sans-serif`
- `font-size` will change the size and is denoted by a "px" value
  - Ex: `font-size: 22px`
- `font-weight` affects the boldness of text, can be used with either the word "bold" or a numeric value for how bold it should be
  - EX: `font-weight: bold` or `font-weight: 700`
  - Numeric values **stay between 100 - 900**
- `text-align` will align text horizontally within an element
  - Ex: `text-align: center`
#### Image Height and Width
- Images and videos can have their display adjusted
- By default, an `<img>` element's `height` and `width` values will be the same as the source image
  - In order to keep the same aspect ratio a value of `auto` is used for the `height`, with a numeric `width` value to match
```CSS
img {
  height: auto;
  width: 500px;
}
```
- In this example if we had an image of **500px height** and **1000px width**, it would be readjusted to a height of **250px**
- Both elements should be included even if you are not changing them from the default values.
  - If not included ***the image will take longer to load than the rest of the page*** contents and it will cause a sudden drastic shift in the page when it readjusts to the image
  - By stating `height` and `width`, we can have the page reserve the area for the image with the rest of the page
#### The Cascade of CSS
- The cascade labels are what dictate how our page looks
- Browsers have default views for buttons and links, etc. and can vary from each browser
#### Specificity
- A CSS declaration that is more specific will take priority over less specific ones.
- Inline styles, have the highest specificity and therefore priority compared to selectors
  - each selector has their own specificity hierarchy as well
    - ID Selectors (most specific selector)
    - Class Selectors
    - Type Selectors(least specific)
- Specificity will only be taken into account when an element has multiple, conflicting declarations targeting it, like a tie-breaker
- When no declaration has a selector with a higher specificity, a larger amount of single selector will beat a smaller amount of that same selector
```HTML
<!-- index.html -->

<div class="main">
  <div class="list subsection"></div>
</div>
```
```CSS
/* rule 1 */
.subsection {
  color: blue;
}

/* rule 2 */
.main .list {
  color: red;
}
```
- In the example above, both rules are using only class selectors, but rule 2 is more specific because it is using more class selectors, so the `color: red;` declaration would take priority
- Ex2:
```HTML
<!-- index.html -->

<div class="main">
  <div class="list" id="subsection"></div>
</div>
```
```CSS
/* rule 1 */
#subsection {
  color: blue;
}

/* rule 2 */
.main .list {
  color: red;
}
```
- In the example above, the div would be *blue* because the `ID` takes priority
```HTML
<!-- index.html -->

<div class="main">
  <div class="list">
    <div id="subsection"></div>
  </div>
</div>
```
```CSS
/* rule 1 */
.list #subsection {
  background-color: yellow;
  color: blue;
}

/* rule 2 */
.main .list #subsection {
  color: red;
}
```
- In the example above, **rule 2 would take priority** because it is more specific
  - Because they both contain `#subsection`, rule2 `color: red;` takes priority with rule1 `background-color: yellow;` because there is no conflict for `background-color`
- > Note: When comparing selectors, you may come across special symbols for the universal selector(`*`) as well as combinators (`+`, `~`, `>`, and an empty space). These symbols do not add any specificity to the elements

-