3b7ed74d11
- examples to fix still
- error_extensions.md ResultExt example does not compile!
- trait ErrorExtensions is not implemented for ParseIntError
- dataloader
- requires sqlx to work. So we either "stub" it OR we rewrite them simpler to use a simple "faux" db library
74 lines
1.7 KiB
Markdown
74 lines
1.7 KiB
Markdown
# 默认值
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你可以为输入值类型定义默认值，下面展示了在不同类型上默认值的定义方法。
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## 对象字段参数
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```rust
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# extern crate async_graphql;
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use async_graphql::*;
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struct Query;
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fn my_default() -> i32 {
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30
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}
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#[Object]
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impl Query {
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// value参数的默认值为0，它会调用i32::default()
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async fn test1(&self, #[graphql(default)] value: i32) -> i32 { todo!() }
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// value参数的默认值为10
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async fn test2(&self, #[graphql(default = 10)] value: i32) -> i32 { todo!() }
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// value参数的默认值使用my_default函数的返回结果，值为30
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async fn test3(&self, #[graphql(default_with = "my_default()")] value: i32) -> i32 { todo!() }
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}
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```
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## 接口字段参数
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```rust
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# extern crate async_graphql;
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# fn my_default() -> i32 { 5 }
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# struct MyObj;
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# #[Object]
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# impl MyObj {
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# async fn test1(&self, value: i32) -> i32 { todo!() }
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# async fn test2(&self, value: i32) -> i32 { todo!() }
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# async fn test3(&self, value: i32) -> i32 { todo!() }
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# }
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use async_graphql::*;
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#[derive(Interface)]
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#[graphql(
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field(name = "test1", type = "i32", arg(name = "value", type = "i32", default)),
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field(name = "test2", type = "i32", arg(name = "value", type = "i32", default = 10)),
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field(name = "test3", type = "i32", arg(name = "value", type = "i32", default_with = "my_default()")),
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)]
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enum MyInterface {
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MyObj(MyObj),
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}
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```
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## 输入对象(InputObject)
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```rust
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# extern crate async_graphql;
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# fn my_default() -> i32 { 5 }
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use async_graphql::*;
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#[derive(InputObject)]
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struct MyInputObject {
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#[graphql(default)]
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value1: i32,
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#[graphql(default = 10)]
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value2: i32,
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#[graphql(default_with = "my_default()")]
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value3: i32,
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}
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```
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