Reputation: 1702
Following is a very simple Nativescript Vue example from the starter. As it appears below, it displays the list of 5 post titles.
So above test is good to start as long as I only use computed
to return data to template. However, if I attempt to use the create()
or mounted()
event/lifecycle hooks to set the posts
property, I get nothing in the display. The console.log
lines never display the message so they're never firing. Why not?
Also, if I try to use the fetch (call my fetchPosts()
method) to pull posts from the test restapi, I get no data and console.error
shows nothing. Why not?
<template>
<Page class="page">
<ActionBar class="action-bar">
<Label class="action-bar-title" text="Home"></Label>
</ActionBar>
<ScrollView>
<StackLayout class="home-panel">
<!--Add your page content here-->
<Label v-for="post in posts" :text="post.title" :key="post.id"/>
</StackLayout>
</ScrollView>
</Page>
</template>
<script>
export default {
// posts: [],
// create() {
// console.log("create event fired");
// this.posts = this.getPosts();
// },
// mounted() {
// console.log("mounted event fired");
// this.posts = this.getPosts();
// },
computed: {
posts() {
//return this.fetchPosts();
return this.getPosts();
}
},
methods: {
fetchPosts() {
fetch("https://jsonplaceholder.typicode.com/posts")
.then(res => res.json())
.then(res => {
console.log("fetch response", res);
return res;
})
.catch(err => {
console.error(err);
return [{ id: 0, title: "Error: " + err }];
});
},
getPosts() {
return [
{
userId: 1,
id: 1,
title:
"sunt aut facere repellat provident occaecati excepturi optio reprehenderit",
body:
"quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto"
},
{
userId: 1,
id: 2,
title: "qui est esse",
body:
"est rerum tempore vitae\nsequi sint nihil reprehenderit dolor beatae ea dolores neque\nfugiat blanditiis voluptate porro vel nihil molestiae ut reiciendis\nqui aperiam non debitis possimus qui neque nisi nulla"
},
{
userId: 1,
id: 3,
title: "ea molestias quasi exercitationem repellat qui ipsa sit aut",
body:
"et iusto sed quo iure\nvoluptatem occaecati omnis eligendi aut ad\nvoluptatem doloribus vel accusantium quis pariatur\nmolestiae porro eius odio et labore et velit aut"
},
{
userId: 1,
id: 4,
title: "eum et est occaecati",
body:
"ullam et saepe reiciendis voluptatem adipisci\nsit amet autem assumenda provident rerum culpa\nquis hic commodi nesciunt rem tenetur doloremque ipsam iure\nquis sunt voluptatem rerum illo velit"
},
{
userId: 1,
id: 5,
title: "nesciunt quas odio",
body:
"repudiandae veniam quaerat sunt sed\nalias aut fugiat sit autem sed est\nvoluptatem omnis possimus esse voluptatibus quis\nest aut tenetur dolor neque"
}
];
}
}
};
</script>
<style scoped lang="scss">
// Start custom common variables
@import "../app-variables";
// End custom common variables
// Custom styles
.fa {
color: $accent-dark;
}
.info {
font-size: 20;
}
</style>
Upvotes: 0
Views: 3323
Reputation: 41
For me it is also not firing, instead of using mounted or created I added a loaded event on the page element
<template>
<page @loaded="startMyApp">
......
</template>
<script>
export default {
data() {
return {
}
},
methods: {
startMyApp()
{
}
}
</script>
Upvotes: 1
Reputation: 1301
There are some problems I identify in your code:
created
, not create
the posts
list should be inside data
:
data() {
return {
posts: []
};
},
the fetchPosts()
doesn't return anything, but you expect to return the posts
. You have to set the posts
inside then
callback:
fetchPosts() {
fetch("https://jsonplaceholder.typicode.com/posts")
.then(res => res.json())
.then(res => this.posts = res)
.catch(err => console.error(err));
}
and this because fetch
returns a Promise
. Q: How to return data from Promise
? A: You can't!
Full code:
<script>
export default {
data() {
return {
posts: [{
title: '1 Title',
id: 1
}]
};
},
created() {
console.log("create event fired");
this.posts = this.fetchPosts();
},
mounted() {
console.log("mounted event fired");
this.fetchPosts();
},
methods: {
fetchPosts() {
return fetch("https://jsonplaceholder.typicode.com/posts")
.then(res => res.json())
.then(res => this.posts = res);
}
}
};
</script>
The code was tested here.
Upvotes: 2