Architecture¶

PdfClient is a single, immutable-after-construction class that implements IPdfClient, wraps one SAIF.Web.API.Clients.JsonHttpClient field for its five remote members, and delegates its six local members to the static PdfAPI.Core.PdfClientService.

Architecture diagram¶

flowchart TD
    CONSUMER[Consuming application] --> IFACE["IPdfClient interface"]
    IFACE --> IMPL["PdfClient : IPdfClient"]
    IMPL --> INFO["ClientInfo<br/>caller-supplied, not populated by PdfClient"]
    IMPL --> HTTP["SAIF.Web.API.Clients.JsonHttpClient"]
    IMPL --> LOCAL["PdfAPI.Core.PdfClientService<br/>6 non-HTTP members"]
    HTTP --> URI["baseUri = url.TrimEnd('/') + '/v1/'"]
    URI --> API["PdfAPI REST API"]
    IMPL --> CONTRACTS["PdfAPI.Core contracts"]
    API --> CONTRACTS

Component responsibilities¶

Component	Type	Responsibility
`IPdfClient`	Interface	The public contract; declares 9 of the client's 11 public members
`PdfClient`	Class	Composes the relative URL per remote member, delegates to `JsonHttpClient`, and forwards local members to `PdfClientService`; also exposes `IsPdfa` and `Track`, which are on the concrete class only
`JsonHttpClient`	`SAIF.Web.API.Clients`	Serialization, transport, timeout, and the `PostJson`/`GetResult` result envelope
`ClientInfo`	`SAIF.Web.API.Clients`	Caller identity sent with each request; supplied by the caller, not built by `PdfClient`
`PdfAPI.Core`	Contracts assembly	Request and response DTOs shared with the API (`ConvertRequest`, `MergeRequest`, `PdfResult`, `PdfTrackingInfo`, `PdfFormat`, `DocumentRange`)
`PdfClientService`	Local service (`PdfAPI.Core.Services`)	Backs the six non-HTTP members: `Version`, `Pages`, `IsPdf`, `HasFormFields`, `Flatten`, `Extract`

Construction¶

PdfClient has exactly one public constructor and no separate initializer. There is no parameterless constructor and no two-phase initializer method — the client cannot be constructed in an uninitialized state, unlike a client with a separate initializer method taking a URL and timeout.

Constructor / initializer	Parameters	Effect
`PdfClient(ClientInfo info, string url)`	`info` — caller-supplied identity; `url` — API base URL	Builds `baseUri` from `url` and constructs the `JsonHttpClient` field, which is `readonly`
Parameterless constructor	—	Not present
Two-phase initializer method	—	Not present

Base URI composition¶

var baseUri = new Uri($"{url.TrimEnd('/')}/v1/");
_jsonHttpClient = new JsonHttpClient(baseUri, info);

Element	Value	Source
Base URL	Caller-supplied `url` constructor argument	`PdfAPI.Client\PdfClient.cs:15`
Version suffix	`v1/`	Hard-coded in `PdfClient.cs:17`
Trailing-slash handling	`url.TrimEnd('/')` applied before appending `/v1/`	`PdfAPI.Client\PdfClient.cs:17`

Both http://host/pdfapi and http://host/pdfapi/ compose the same base URI. There is no guard on url itself: a null value throws NullReferenceException from TrimEnd, and an empty/relative value throws UriFormatException from the Uri constructor.

ClientInfo population¶

Property	Value	Source
`ApplicationId`	Not set by `PdfClient`	Caller-supplied `info` argument, used as-is
`MachineName`	Not set by `PdfClient`	Caller-supplied `info` argument, used as-is
`UserId`	Not set by `PdfClient`	Caller-supplied `info` argument, used as-is

Every consumer observed in scope passes a default-constructed, empty ClientInfo (PdfApiClientTester\PdfApiClientTester\PdfTester.cs:23), so no application, machine, or user identity is populated by any caller in this repository.

Call pattern¶

Each remote member follows the same shape: compose a relative URL, call one JsonHttpClient method, and unwrap the result.

`JsonHttpClient` member	Returns	Used by this client for
`GetResult<T>(url)`	`T`, returned directly with no unwrapping	`Track(long)` only
`GetResults<T>(url)`	`T[]`	Not used by this client
`PostJson<T>(url, body)`	Result envelope with `.Results`	`Convert` (both overloads), `Merge`, `IsPdfa` — each unwraps with `.Results.FirstOrDefault()`

An empty .Results collection from PostJson<T> silently yields default(T) — false for IsPdfa, null for Convert/Merge — with no exception raised. See Tech debt.

Design constraints¶

No public constructor or member accepts a CancellationToken; every remote call is fully synchronous and blocks the calling thread for the HTTP round trip.
The single constructor makes _jsonHttpClient a readonly field assigned once, so an instance is immutable and has no shared mutable state after construction.
The vestigial private readonly string _pdfRootDirectory; field (PdfClient.cs:13) is declared but never assigned or read.

Inherited framework behavior¶

Serialization, request composition, timeout enforcement, and the PostJson/GetResult result envelope are implemented inside SAIF.Web.API.Clients.JsonHttpClient and are not re-documented here.

Sources¶

PdfAPI.Client\PdfClient.cs
PdfAPI.Client\IPdfClient.cs
PdfAPI.Core\Services\PdfClientService.cs