Client access

The integration shares one *polipage.Client across every handler. polipagegin.Middleware stores it on the *gin.Context of each request, and polipagegin.ClientFrom(c) reads it back. The client is safe for concurrent use and pools connections, so build it once at startup.

ClientFrom

polipagegin.ClientFrom(c) returns the typed *polipage.Client. It panics with a clear message when Middleware was not installed on the route, or when something overwrote the context key with another type:

polipagegin: Middleware(client) not installed; add r.Use(polipagegin.Middleware(client))

Gin’s Recovery() turns the panic into a 500. gin.Default() registers it; with gin.New() you add it yourself. See Middleware.

The context key

The client lives under the context key polipagegin.ContextKey, whose value is "polipagegin.client". Custom middleware, for example one that swaps the client per tenant, can write or read the same slot with c.Set and c.Get.

Gin’s context is a map[string]any. Reusing the string "polipagegin.client" for your own value silently overwrites the client, so use the exported constant.

Per-group clients

A second Middleware on a router group replaces the client for that group’s routes. See Middleware.

Request context

Pass c.Request.Context() to every SDK call, never context.Background(). Gin cancels the request context when the client disconnects, and the SDK then aborts in flight with polipage.ErrAborted. With context.Background() the render keeps running after the connection closes.

Example

invoice_handler.go

func invoiceHandler(c *gin.Context) {
  client := polipagegin.ClientFrom(c)

  pdf, err := client.Render.PDF(c.Request.Context(), polipage.RenderInput{
    Project:  "billing",
    Template: "invoice",
    Data:     map[string]any{"invoiceNumber": "INV-001"},
  })
  if err != nil {
    polipagegin.WriteError(c, err)
    return
  }
  polipagegin.PDF(c, pdf, polipagegin.PDFOptions{Filename: "invoice.pdf"})
}

// A soft accessor that does not panic when the middleware is missing:
func clientOrNil(c *gin.Context) *polipage.Client {
  v, ok := c.Get(polipagegin.ContextKey)
  if !ok {
    return nil
  }
  client, _ := v.(*polipage.Client)
  return client
}

See also

• Configuration
• Responses
• Testing