added webpage tutorial and a build command for first app tutorial

This commit is contained in:
The-EDev 2022-06-03 21:21:39 +03:00 committed by Farook Al-Sammarraie
parent 2788a910b9
commit d599295731
3 changed files with 133 additions and 3 deletions

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Hello World is a good start, but what if you want something a bit more fancy.. Something like an HTML document saying "Hello World". If that's what you want, follow along:
## Basic Webpage
Let's start our webpage with.. well.. a webpage. but before we create a webpage we need to place it somewhere Crow recognizes, this directory (for now) is going to be called `templates`.
Once our `templates` folder is created, we can create our HTML document inside it, let's call it `fancypage.html`.
After that we can just place something simple inside it like:
``` html title="templates/fancypage.html"
<!DOCTYPE html>
<html>
<body>
<p>Hello World!</p>
</body>
</html>
```
<br>
Now that we have our HTML page ready, let's take our Hello World example from earlier:
``` cpp linenums="1"
#include "crow.h"
//#include "crow_all.h"
int main()
{
crow::SimpleApp app; //define your crow application
//define your endpoint at the root directory
CROW_ROUTE(app, "/")([](){
return "Hello world";
});
//set the port, set the app to run on multiple threads, and run the app
app.port(18080).multithreaded().run();
}
```
<br>
And now let's modify it so that it returns our cool page:
``` cpp title="/main.cpp" linenums="1" hl_lines="10 11"
#include "crow.h"
//#include "crow_all.h"
int main()
{
crow::SimpleApp app;
//define your endpoint at the root directory
CROW_ROUTE(app, "/")([](){
auto page = crow::mustache::load_text("fancypage.html");
return page;
});
app.port(18080).multithreaded().run();
}
```
Your project should look something something like:
```
./
|-templates/
| |-fancypage.html
|
|-main.cpp
|-crow_all.h
```
or
```
./
|-templates/
| |-fancypage.html
|
|-crow/
| |-include/...
| |-crow.h
|-main.cpp
```
And now whenever we call `http://localhost:18080/` we get our Hello World in an HTML document rather than just plain text.
## Template Webpage with a variable
But we can make things even more exciting, we can greet a user by their name instead!!
Let's start with our webpage, and modify it with a little bit of mustache syntax:
``` html title="templates/fancypage.html" hl_lines="4"
<!DOCTYPE html>
<html>
<body>
<p>Hello {{person}}!</p> <!--(1)-->
</body>
</html>
```
1. `{{}}` in mustache define a simple variable
<br>
Now let's modify our C++ code to use the variable we just added to our webpage (or template):
``` cpp title="/main.cpp" linenums="1" hl_lines="9-12"
#include "crow.h"
//#include "crow_all.h"
int main()
{
crow::SimpleApp app;
//define your endpoint at the root directory
CROW_ROUTE(app, "/<string>")([](std::string name){ // (1)
auto page = crow::mustache::load("fancypage.html"); // (2)
crow::mustache::context ctx ({{"person", name}}); // (3)
return page.render(ctx); //(4)
});
app.port(18080).multithreaded().run();
}
```
1. We are adding a `string` variable to the URL and a counterpart (`std::string name`) to our Route, this can be anything the user wants.
2. We are using `load()` instead of `load_text()` since we have an actual variable now.
3. We are creating a new [context](../../guides/templating/#context) containing the `person` variable from our template and the `name` we got from the URL.
4. we are using `render(ctx)` to apply our context to the template.
Now calling `http://localhost:18080/Bob` should return a webpage containing "Hello Bob!". We did it!
For more details on templates and HTML pages in Crow please go [here](../../guides/templating/)

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@ -38,7 +38,7 @@ Please note that the `port()` and `multithreaded()` methods aren't needed, Thoug
Once you've followed all the steps above, your code should look similar to this
``` cpp linenums="1"
``` cpp title="main.cpp" linenums="1"
#include "crow.h"
//#include "crow_all.h"
@ -55,4 +55,7 @@ int main()
app.port(18080).multithreaded().run();
}
```
After building and running your .cpp file, you should be able to access your endpoint at [http://localhost:18080](http://localhost:18080). Opening this URL in your browser will show a white screen with "Hello world" typed on it.
For the sake of simplicity, we suggest using `crow_all.h` (by placing it in the same place as your `main.cpp`) and running the command `g++ main.cpp -lpthread -O2 -o first` (use `clang` instead of `g++` if you prefer clang, or Visual Studio if you're on windows).
After building and running your `.cpp` file, you should be able to access your endpoint at [http://localhost:18080](http://localhost:18080). Opening this URL in your browser will show a white screen with "Hello world" typed on it.

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@ -11,7 +11,8 @@ theme:
font: false
language: 'en'
features:
navigation.tabs
- navigation.tabs
- content.code.annotate
favicon: 'assets/favicon.svg'
logo: 'assets/favicon.svg'
icon:
@ -54,6 +55,7 @@ nav:
- MacOS: getting_started/setup/macos.md
- Windows: getting_started/setup/windows.md
- Your First Application: getting_started/your_first_application.md
- A simple Webpage: getting_started/a_simple_webpage.md
- Guides:
- Different parts of Crow:
- App: guides/app.md