Swift Requires Chilkat v11.7.0+

Deflate Compression Level When Optimizing a PDF

See more PDF Optimization Examples

Demonstrates compressionLevel, which is the deflate level (1 to 9, 9 by default) used for every stream the optimizer re-encodes. Level 9 is the smallest and the slowest; level 1 is the quickest. The difference is usually a percent or two, so level 9 is the right default for a file that will be downloaded many times, and a lower level is worth considering only when a server optimizes PDFs on the fly. A value outside 1 to 9 is an error. Swift

func chilkatTest() {
    var success: Bool = false

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  The PDF used in this example is available at watersense_accomplishments.pdf

    let fac = CkoFileAccess()!
    let json = CkoJsonObject()!
    let jsonOut = CkoJsonObject()!

    let pdf1 = CkoPdf()!
    success = pdf1.loadFile(filePath: "qa_data/pdf/watersense_accomplishments.pdf")
    if success == false {
        print("\(pdf1.lastErrorText!)")
        return
    }

    json.updateInt(jsonPath: "compressionLevel", value: 1)
    success = pdf1.optimize(op: "optimize", jsonIn: json, jsonOut: jsonOut)
    if success == false {
        print("\(pdf1.lastErrorText!)")
        return
    }

    success = pdf1.writeFile(path: "qa_output/watersense_level1.pdf")
    if success == false {
        print("\(pdf1.lastErrorText!)")
        return
    }

    print("level 1: \(fac.fileSize(path: "qa_output/watersense_level1.pdf").intValue)")

    let pdf9 = CkoPdf()!
    success = pdf9.loadFile(filePath: "qa_data/pdf/watersense_accomplishments.pdf")
    if success == false {
        print("\(pdf9.lastErrorText!)")
        return
    }

    json.updateInt(jsonPath: "compressionLevel", value: 9)
    success = pdf9.optimize(op: "optimize", jsonIn: json, jsonOut: jsonOut)
    if success == false {
        print("\(pdf9.lastErrorText!)")
        return
    }

    success = pdf9.writeFile(path: "qa_output/watersense_level9.pdf")
    if success == false {
        print("\(pdf9.lastErrorText!)")
        return
    }

    print("level 9: \(fac.fileSize(path: "qa_output/watersense_level9.pdf").intValue)")

    //  A level outside 1..9 fails, and LastErrorText says why.
    let pdfBad = CkoPdf()!
    success = pdfBad.loadFile(filePath: "qa_data/pdf/watersense_accomplishments.pdf")
    if success == false {
        print("\(pdfBad.lastErrorText!)")
        return
    }

    json.updateInt(jsonPath: "compressionLevel", value: 12)
    success = pdfBad.optimize(op: "optimize", jsonIn: json, jsonOut: jsonOut)
    if success == false {
        print("compressionLevel 12 was refused, as it should be.")
    }


}