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<ol class="chapter"><li class="chapter-item expanded "><a href="../warpgrapher/intro.html"><strong aria-hidden="true">1.</strong> Warpgrapher</a></li><li class="chapter-item expanded "><a href="../warpgrapher/quickstart.html"><strong aria-hidden="true">2.</strong> Quickstart</a></li><li class="chapter-item expanded "><a href="../integrations/intro.html"><strong aria-hidden="true">3.</strong> Server Integration</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../integrations/actix.html"><strong aria-hidden="true">3.1.</strong> Actix Web</a></li><li class="chapter-item expanded "><a href="../integrations/lambda.html"><strong aria-hidden="true">3.2.</strong> AWS Lambda</a></li></ol></li><li class="chapter-item expanded "><a href="../configuration/intro.html"><strong aria-hidden="true">4.</strong> Configuration</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../configuration/databases.html"><strong aria-hidden="true">4.1.</strong> Databases</a></li><li class="chapter-item expanded "><a href="../configuration/formats.html"><strong aria-hidden="true">4.2.</strong> Formats</a></li><li class="chapter-item expanded "><a href="../configuration/types.html"><strong aria-hidden="true">4.3.</strong> Types</a></li><li class="chapter-item expanded "><a href="../configuration/relationships.html"><strong aria-hidden="true">4.4.</strong> Relationships</a></li></ol></li><li class="chapter-item expanded "><a href="../api/intro.html"><strong aria-hidden="true">5.</strong> CRUD API Usage Examples</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../api/node_create.html"><strong aria-hidden="true">5.1.</strong> Node Create</a></li><li class="chapter-item expanded "><a href="../api/node_read.html"><strong aria-hidden="true">5.2.</strong> Node Read</a></li><li class="chapter-item expanded "><a href="../api/node_update.html"><strong aria-hidden="true">5.3.</strong> Node Update</a></li><li class="chapter-item expanded "><a href="../api/node_delete.html"><strong aria-hidden="true">5.4.</strong> Node Delete</a></li><li class="chapter-item expanded "><a href="../api/rel_create.html"><strong aria-hidden="true">5.5.</strong> Relationship Create</a></li><li class="chapter-item expanded "><a href="../api/rel_read.html"><strong aria-hidden="true">5.6.</strong> Relationship Read</a></li><li class="chapter-item expanded "><a href="../api/rel_update.html"><strong aria-hidden="true">5.7.</strong> Relationship Update</a></li><li class="chapter-item expanded "><a href="../api/rel_delete.html"><strong aria-hidden="true">5.8.</strong> Relationship Delete</a></li></ol></li><li class="chapter-item expanded "><a href="../engine/intro.html"><strong aria-hidden="true">6.</strong> Engine Features</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="../engine/endpoints_static.html"><strong aria-hidden="true">6.1.</strong> Static Endpoints</a></li><li class="chapter-item expanded "><a href="../engine/endpoints_defined.html"><strong aria-hidden="true">6.2.</strong> Defined Endpoints</a></li><li class="chapter-item expanded "><a href="../engine/dynamic_props.html"><strong aria-hidden="true">6.3.</strong> Dynamic Props</a></li><li class="chapter-item expanded "><a href="../engine/dynamic_rels.html"><strong aria-hidden="true">6.4.</strong> Dynamic Relationships</a></li><li class="chapter-item expanded "><a href="../engine/context_request.html"><strong aria-hidden="true">6.5.</strong> Request Context</a></li><li class="chapter-item expanded "><a href="../engine/input_validation.html" class="active"><strong aria-hidden="true">6.6.</strong> Input Validation</a></li><li class="chapter-item expanded "><a href="../engine/event_handlers.html"><strong aria-hidden="true">6.7.</strong> Event Handlers</a></li></ol></li></ol>
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<h1 id="input-validation"><a class="header" href="#input-validation">Input Validation</a></h1>
<p>In many cases, it's necessary to ensure that inputs are valid. What constitutes a valid input is up to the application, but it may mean that values have to be less than a certain length, within a certain range, and/or include or exclude certain characters. Warpgrapher makes it possible to write custom validation functions to reject invalid inputs.</p>
<h2 id="configuration"><a class="header" href="#configuration">Configuration</a></h2>
<p>In the configuration snippet below, the <code>name</code> property has a <code>validator</code> field with the name <code>NameValidator</code>. The <code>NameValidator</code> string will be used later to connect the Rust function with this definition in the schema.</p>
<pre><code class="language-rust no_run noplayground">version: 1
model:
<span class="boring"> User
</span> - name: User
props:
- name: name
type: String
required: true
validator: NameValidator
</code></pre>
<h2 id="implementation"><a class="header" href="#implementation">Implementation</a></h2>
<p>The implementation below defines the input validation function itself. The function is relatively simple, rejecting the input if the name is "KENOBI". All other names are accepted.</p>
<pre><code class="language-rust no_run noplayground">fn name_validator(value: &Value) -> Result<(), Error> {
if let Value::Map(m) = value {
if let Some(Value::String(name)) = m.get("name") {
if name == "KENOBI" {
Err(Error::ValidationFailed {
message: format!(
"Input validator for {field_name} failed. Cannot be named KENOBI",
field_name = "name"
),
})
} else {
Ok(())
}
} else {
Err(Error::ValidationFailed {
message: format!(
"Input validator for {field_name} failed.",
field_name = "name"
),
})
}
} else {
Err(Error::ValidationFailed {
message: format!(
"Input validator for {field_name} failed.",
field_name = "name"
),
})
}
}
</code></pre>
<h2 id="add-validators-to-the-engine"><a class="header" href="#add-validators-to-the-engine">Add Validators to the Engine</a></h2>
<p>The validators, such as the one defined above, are packaged into a map from the name(s) used in the configuration to the Rust functions. The map is then provided to the Warpgrapher <code>Engine</code> as the engine is built.</p>
<pre><code class="language-rust no_run noplayground"> // load validators
let mut validators: Validators = Validators::new();
validators.insert("NameValidator".to_string(), Box::new(name_validator));
// create warpgrapher engine
let engine: Engine<AppRequestContext> = Engine::new(config, db)
.with_validators(validators.clone())
.build()
.expect("Failed to build engine");
</code></pre>
<h2 id="example-api-call"><a class="header" href="#example-api-call">Example API Call</a></h2>
<p>The follow example API call invokes the validator defined above.</p>
<pre><code class="language-rust no_run noplayground"> let query = "
mutation {
UserCreate(input: {
name: \"KENOBI\"
}) {
id
name
}
}
"
.to_string();
let metadata = HashMap::new();
let result = engine.execute(query, None, metadata).await.unwrap();
</code></pre>
<h2 id="full-example-source"><a class="header" href="#full-example-source">Full Example Source</a></h2>
<p>See below for the full source code to the example above.</p>
<pre><code class="language-rust no_run noplayground">use std::collections::HashMap;
use std::convert::TryFrom;
use warpgrapher::engine::config::Configuration;
use warpgrapher::engine::context::RequestContext;
use warpgrapher::engine::database::cypher::CypherEndpoint;
use warpgrapher::engine::database::DatabaseEndpoint;
use warpgrapher::engine::validators::Validators;
use warpgrapher::engine::value::Value;
use warpgrapher::{Engine, Error};
static CONFIG: &str = "
version: 1
model:
<span class="boring"> User
</span> - name: User
props:
- name: name
type: String
required: true
validator: NameValidator
";
#[derive(Clone, Debug)]
struct AppRequestContext {}
impl RequestContext for AppRequestContext {
type DBEndpointType = CypherEndpoint;
fn new() -> AppRequestContext {
AppRequestContext {}
}
}
fn name_validator(value: &Value) -> Result<(), Error> {
if let Value::Map(m) = value {
if let Some(Value::String(name)) = m.get("name") {
if name == "KENOBI" {
Err(Error::ValidationFailed {
message: format!(
"Input validator for {field_name} failed. Cannot be named KENOBI",
field_name = "name"
),
})
} else {
Ok(())
}
} else {
Err(Error::ValidationFailed {
message: format!(
"Input validator for {field_name} failed.",
field_name = "name"
),
})
}
} else {
Err(Error::ValidationFailed {
message: format!(
"Input validator for {field_name} failed.",
field_name = "name"
),
})
}
}
#[tokio::main]
async fn main() {
// parse warpgrapher config
let config = Configuration::try_from(CONFIG.to_string()).expect("Failed to parse CONFIG");
// define database endpoint
let db = CypherEndpoint::from_env()
.expect("Failed to parse cypher endpoint from environment")
.pool()
.await
.expect("Failed to create cypher database pool");
// load validators
let mut validators: Validators = Validators::new();
validators.insert("NameValidator".to_string(), Box::new(name_validator));
// create warpgrapher engine
let engine: Engine<AppRequestContext> = Engine::new(config, db)
.with_validators(validators.clone())
.build()
.expect("Failed to build engine");
let query = "
mutation {
UserCreate(input: {
name: \"KENOBI\"
}) {
id
name
}
}
"
.to_string();
let metadata = HashMap::new();
let result = engine.execute(query, None, metadata).await.unwrap();
println!("result: {:#?}", result);
}
</code></pre>
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