To create a new page, accessible from the navbar with a given icon
The page will displays in real time the total number of observation.
The page will first uses event handling to dynamically animate text.
A new observation from another user should be reflected immediately in the counter. A new observation from the current user should update the counter.
The page will then calls an external web-service \(wikipedia API\) to populate and animate content.
## Steps to follow
### Start using the tools
* Start Albiziapp locally \(you might have to kill already running albiziapp processes\)
{% hint style="info" %}
Use`vue ui`from the albiziapp/ directory then Task`->`Serve`->`Run task
{% endhint %}
This action triggers the source dependencies injection, their bundling and then start serving Albiziapp at [http://localhost:8080/](http://localhost:8080/)
{% hint style="info" %}
From vue-dashboard on top left menu : "open in editor" . It should open VSCode.
{% endhint %}
* Create a .vue file in the pages directory. **The file should start with a capital case**.
This file is first empty. Let's fill it a bit :
{% hint style="info" %}
Use Ctrl-Space to trigger the powerful autocomplete. Chose the first option
{% endhint %}
Your Test.vue should now look like below.
```javascript
<template>
</template>
<script>
exportdefault{
}
</script>
<style>
</style>
```
Using autocomplete, populate the template. Add the v-ons-page element as direct child of template. Then add something to display for test purposes \(here a div\).
```javascript
<template>
<v-ons-page>
<divclass="content">Hellopage</div>
</v-ons-page>
</template>
```
### Add your page to the tabbar
So far, you added a .vue file but the web app do not "knows" about it. The newly created .vue file must be [imported](https://vuejs.org/v2/guide/single-file-components.html#Introduction).
Let's import this component where it belongs : in AppTabbar.vue.
* Open AppTabbar.vue like a pro \(using Ctrl-P\)
From the source below \(extracted from AppTabbar\), **figure out the syntax for importing your newly created page.**
{% code title="AppTabbar.vue" %}
```javascript
importPusherfrom"pusher-js";
importMapfrom"./pages/Map.vue";
importHomefrom"./pages/Home.vue";
importProfilefrom"./pages/Profile.vue";
importArboretumfrom"./pages/Arboretum.vue";
importRelevefrom"./pages/Releves.vue";
importFoliafrom"./pages/Folia.vue";
```
{% endcode %}
Actually type the import line and save.
{% hint style="info" %}
**Any file modification** triggers a reload of the application in development mode
This is very convenient : it permits to know exactly when a change breaks the app.
{% endhint %}
Your new page isn't yet in the tabbar. To make it happen, you need to change the value of the `tabs()` function.
This function returns an array of objects, **each element of the array represent an item in the tabbar**.
```javascript
tabs(){
vartab=
[
{
label:this.$t('map'),
icon:"ion-map",
active:false,
page:Map,
theme:red
},
{
label:this.$t('mission'),
icon:"ion-home",
page:Home,
theme:red
},
// ....
{
label:"Folia",
icon:"ion-search",
page:Folia,
theme:purple
}
];
// .....
returntab
},
```
Taking inspiration from the last item of the array \(Folia\), add a new object defining your page to the array. This object will have three properties :
*`icon type String`
*`label type String`
*`page type Object`
{% hint style="info" %}
To find a correct icon property value, find the desired icon in [ioniconics](https://ionicons.com/). Then append "ion-" to the icon name. \([ref](https://onsen.io/v2/api/vue/v-ons-icon.html)\)
{% endhint %}
You should now have a new tab entry leading to your newly created page.
###
### Optional challenge : make it prettier
...
...
@@ -232,5 +103,17 @@ export default {
```
The `text` variable is here declared and initialized. It is now possible to refer to `text` in the UI.
The `text` variable is here declared and initialized. It is now possible to refer to `text` in the UI. The`{{text}}` item in the div is a simple illustration of this use.
The double mustache syntax evaluates the value of the **javascript expression** it contains, and return the string representation of this expression. Practically it gives a lot of power. Replace {{text}} by the following examples.
```javascript
{{text.toUpperCase()}}
{{text.split('').sort().join().split('')}}
```
#### Practical example : fetching data from an external source
Data do not have to be defined at creation. Let's explore an example using data recovered from an external source.
So far, you added a .vue file but the web app do not "knows" about it. The newly created .vue file must be [imported](https://vuejs.org/v2/guide/single-file-components.html#Introduction).
Let's import this component where it belongs : in AppTabbar.vue.
* Open AppTabbar.vue like a pro \(using Ctrl-P\)
From the source below \(extracted from AppTabbar\), **figure out the syntax for importing your newly created page.**
{% code title="AppTabbar.vue" %}
```javascript
importPusherfrom"pusher-js";
importMapfrom"./pages/Map.vue";
importHomefrom"./pages/Home.vue";
importProfilefrom"./pages/Profile.vue";
importArboretumfrom"./pages/Arboretum.vue";
importRelevefrom"./pages/Releves.vue";
importFoliafrom"./pages/Folia.vue";
```
{% endcode %}
Actually type the import line and save.
{% hint style="info" %}
**Any file modification** triggers a reload of the application in development mode
This is very convenient : it permits to know exactly when a change breaks the app.
{% endhint %}
Your new page isn't yet in the tabbar. To make it happen, you need to change the value of the `tabs()` function.
This function returns an array of objects, **each element of the array represent an item in the tabbar**.
```javascript
tabs(){
vartab=
[
{
label:this.$t('map'),
icon:"ion-map",
active:false,
page:Map,
theme:red
},
{
label:this.$t('mission'),
icon:"ion-home",
page:Home,
theme:red
},
// ....
{
label:"Folia",
icon:"ion-search",
page:Folia,
theme:purple
}
];
// .....
returntab
},
```
Taking inspiration from the last item of the array \(Folia\), add a new object defining your page to the array. This object will have three properties :
*`icon type String`
*`label type String`
*`page type Object`
{% hint style="info" %}
To find a correct icon property value, find the desired icon in [ioniconics](https://ionicons.com/). Then append "ion-" to the icon name. \([ref](https://onsen.io/v2/api/vue/v-ons-icon.html)\)
{% endhint %}
You should now have a new tab entry leading to your newly created page.
Start Albiziapp locally \(you might have to kill already running albiziapp processes\)
{% hint style="info" %}
Use`vue ui`from the albiziapp/ directory then Task`->`Serve`->`Run task
{% endhint %}
This action triggers the source dependencies injection, their bundling and then start serving Albiziapp at [http://localhost:8080/](http://localhost:8080/)
{% hint style="info" %}
From vue-dashboard on top left menu : "open in editor" . It should open VSCode.
{% endhint %}
* Create a .vue file in the pages directory. **The file should start with a capital case**.
This file is first empty. Let's fill it a bit :
{% hint style="info" %}
Use Ctrl-Space to trigger the powerful autocomplete. Chose the first option
{% endhint %}
Your Test.vue should now look like below.
```javascript
<template>
</template>
<script>
exportdefault{
}
</script>
<style>
</style>
```
Using autocomplete, populate the template. Add the v-ons-page element as direct child of template. Then add something to display for test purposes \(here a div\).
### Introducing reactivity : dynamic number of observations
After having created static content, we will now use this content to use reactivity. Reactivity is at the core of VueJS.
{% hint style="info" %}
Beyond Albiziapp and VueJS, reactive programming is a research topic in itself \(that has relations with MDE although no clear consensus exists\).
{% endhint %}
In the case of Albiziapp, reactivity means :
* Data are declarative. The UI reacts automatically to data change.
* => The UI should not change if there are no data change
* Derived data are bounded to the original data.
* If `a=b+c` each time `b or c` are changed, a will change accordingly.
* Data changes occurring in a subcomponent are reflected in the parent components
#### Practical example : mutating data
In the new page script, let's declare a `data()` function. This function is used in VueJS to create simple reactive data. For convenience, use the following code.
```javascript
<template>
<v-ons-page>
<divclass="content center">{{text}}</div>
</v-ons-page>
</template>
<script>
exportdefault{
data(){
return{
text:"interest"
};
}
};
</script>
<style>
.center{
position:relative;
top:50%;
left:50%;
}
</style>
```
The `text` variable is here declared and initialized. It is now possible to refer to `text` in the UI. The`{{text}}` item in the div is a simple illustration of this use.
The double mustache syntax evaluates the value of the **javascript expression** it contains, and return the string representation of this expression. Practically it gives a lot of power. Replace {{text}} by the following examples.
The current version of the new page isn't very visually appealing. This challenge is to make the page looking like a web startup front page.
Somethings that says _"We are so amazing you wouldn't even understand" ._ Look at [startup generator](http://tiffzhang.com/startup) if you need inspiration.
To that end, you can use two features of OnsenUI, **page background** and **cards**.
#### Page background
The v-ons-page component comes with a easy to use background effect. To use it, simply add a new children div where `class="background"` This will be interpreted as a static background.
OnsenUI card component \([v-ons-card](https://onsen.io/v2/api/vue/v-ons-card.html)\) permit to group related information. Cards have a **title** and a **content.** Title and content are div where `class="title"` and `class="content"` respectively.
