pygenpdf-json 0.1.17
Python bindings to Rust's genpdf-json library (PDF generator)
Requires Python: >=3.8

# pygenpdf_json

It is a Fast PDF generator through JSON.

pygenpdf_json uses genpdf-json(https://github.com/numaelis/genpdf-json-rs) thanks to pyo3 and maturin 

genpdf-json uses rckive-genpdf and generates a PDF from JSON data.

rckive-genpdf is a user-friendly PDF generator written in pure Rust.

The library can be used in two ways:

1. Search for a JSON file and create a new PDF file in the specified path.
2. Pass a JSON string and receive a PDF file in Base64 text.

The JSON can be passed directly or using an sqlite.db file

Another way to use it is through the pygenpdf library (https://gitlab.com/numaelis/pygenpdf)

Options:
```
pygenpdf_json.render_json_file("file.json", "report.pdf")

file_pdf_base64 = pygenpdf_json.render_json_base64(json_string)

pygenpdf_json.render_file_from_sqlite("file.db", "report.pdf")

file_pdf_base64 = pygenpdf_json.render_base64_from_sqlite("file.db")

```

The structure of the document is:
```
    {
        "config": {...},
        "elements": [...elements...]
    }
```

examples:
```
import pygenpdf_json
pygenpdf_json.render_json_file("file.json", "file.pdf")
```

The file.json:

```
{
    "config": {
        "title": "report genpdf", 
        "style": {}, 
        "page_size": "A4", 
        "fonts": [], 
        "default_font": {"font_family_name": "LiberationSans", "dir": "/usr/share/fonts/truetype/liberation"}, 
        "head_page": {"type": "paragraph", "value": [{"text": "report genpdf-rs", "bold": true, "size": 8, "italic": true}], "alignment": "right"}, 
        "margins": [7, 10, 10, 10], "line_spacing": 1.0
        }, 
    "elements": [
                    {
                        "type": "layout", 
                        "orientation": "vertical", 
                        "elements": [
                                        {
                                            "type": "paragraph", 
                                            "value": [{"text": "Invoice", "bold": true, "size": 25}], 
                                            "alignment": "center"}, 
                                        {"type": "break", "value": 1}
                                    ], 
                        "frame": {"thickness": 0.1}, 
                        "padding": [1, 1, 1, 1]
                    }, 
                    {"type": "break", "value": 2}, 
                    {
                        "type": "paragraph", 
                        "value": [{"text": "details", "bold": true, "size": 12}], 
                        "alignment": "center"
                    }                
            ]
}
```

example base64:
```
import pygenpdf_json

string_json = """{
        "config": {
            "title": "report genpdf", 
            "style": {}, 
            "page_size": "A4", 
            "fonts": [], 
            "default_font": {"font_family_name": "LiberationSans", "dir": "/usr/share/fonts/truetype/liberation"}, 
            "head_page": {"type": "paragraph", "value": [{"text": "report genpdf-rs", "bold": true, "size": 8, "italic": true}], "alignment": "right"}, 
            "margins": [7, 10, 10, 10], "line_spacing": 1.0
            }, 
        "elements": [
                        {
                            "type": "layout", 
                            "orientation": "vertical", 
                            "elements": [
                                            {
                                                "type": "paragraph", 
                                                "value": [{"text": "Invoice", "bold": true, "size": 25}], 
                                                "alignment": "center"}, 
                                            {"type": "break", "value": 1}
                                        ], 
                            "frame": {"thickness": 0.1}, 
                            "padding": [1, 1, 1, 1]
                        }, 
                        {"type": "break", "value": 2}, 
                        {
                            "type": "paragraph", 
                            "value": [{"text": "details", "bold": true, "size": 12}], 
                            "alignment": "center"
                        }                
                ]
    }"""

pdf_string_base64 = pygenpdf_json.render_json_base64(string_json)
print(pdf_string_base64)
```

SQLite:
To save the config:
In a table called config, use a column named data (Text), and in this column, save a record with the config's JSON.
For the elements:
In a table called elements, use the id (autoincrement) column and the element (Text) column, and save the elements in each record in the JSON order.
Optionally, for table layouts, save the rows in a new table separate from config and elements, with the structure id (autoincrement) and row (Text). Then, reassign the value to the JSON "rows" with the name of the table created.

```
import pygenpdf_json

render_file_from_sqlite("database.db", "output.pdf")

#or

pdf_string_base64 = pygenpdf_json.render_base64_from_sqlite("database.db")
```


#Type support

config:
```
"config":{
    "title":"", 
    "style": style, 
    "page_size": string or [float, float]  -> "A4", "Legal", "Letter", or [200,200]
    "fonts" : [{"font_family_name":"", dir:""}],
    "default_font": {"font_family_name":"", dir:""}
    "line_spacing": float,
    "margins": [float, float, float, float],
    "head_page": paragraph, or [paragraph, paragraph, paragraph] maximum 3 paragraphs
    "footer_page": [paragraph, paragraph, paragraph] maximum 3 paragraphs
    "head_page_count": paragraph,
    "header_frame": line_style,
    "footer_frame": line_style,
    "page_frame": line_style,
    "page_frame_width_offset": float, -> A negative value reduces the width
    "header_logo" : {"left": image, "right": image}, omit what is not used
    "footer_logo" : {"left": image, "right": image}, omit what is not used
    "header_column_weights": [1,1,1], in case of using all three (image, paragraphs, image)
    "footer_column_weights": [1,1,1], default 1
    "deafault_font_size": int,
    "skip_warning_overflowed": bool -> Skip the page size exceeded warning when the paragraph exceeds the layout
}
```

line_style:
```
 {
    "thickness":float,
    "color":color,
    "dash": int, "gap": int, "dash2": int, "gap2": int,
    "top": bool, "right": bool, "bottom": bool, "left": bool (only frame),
    "background": bool, (only frame)
    "background_color": color, (only frame)
 }
```

margins:
```
    [top, right, bottom, left]  float or int
```

style:
```
 {
    "bold":bool,
    "italic":bool,
    "font_family_name": string,
    "color": color,
    "line_spacing": float,
    "size": int,
    "fit_size_to": int -> auto size to minimum
 }
```

alignment:
```
    "left"
    "center"
    "right"
```

string_style:
```
 {
    "text": string
    "bold":bool,
    "italic":bool,
    "font_family_name": string,
    "color": color,
    "line_spacing": float,
    "size": int,
    "fit_size_to": int -> auto size to minimum
 }
```

color:
```
    {"type":"rgb", "value":[int, int, int]} 0 - 255
    {"type":"cmyk", "value":[int, int, int, int]}
    {"type":"greyscale", "value":int}
```
elements
```
 {
    "type": layout,
    "orientation":"vertical"
    "frame": line_style,
    "style": style,
    "padding": margins,
    "orphan": bool,
    "position": [float, float],
    "elements": [...elements...]
 }
 
 {
    "type": layout,
    "orientation":"horizontal"
    "column_weights": [], array of integers
    "frame": line_style,
    "style": style,
    "padding": margins,
    "elements": [...elements column_weights.len()...]
 }
 
 {
    "type": table_layout,
    "frame_decorator":[[inner(bool), outer(bool), cont(bool)], line_style]
    "column_weights": [], array of integers
    "frame": line_style,
    "style": style,
    "padding": margins,
    "rows": [...rows column_weights.len()...]
 }
 
 {
    "type": unordered_list,
    "frame": line_style,
    "style": style,
    "padding": margins,
    "elements": [...elements...],
    "bullet": string
 }
 
 {
    "type": ordered_list,
    "frame": line_style,
    "style": style,
    "padding": margins,
    "elements": [...elements...],
    "start": int
 }
 
 {
    "type": paragraph,
    "frame": line_style,
    "style": style,
    "padding": margins,
    "value": [...string_style...]
    "alignment" alignment
    "bullet": string
 }
 
 {
    "type": text,
    "value": string_style,
    "orphan": bool,
    "position": [float, float]
 }
 
 {
    "type": image,
    "path": string,
    "base64": string,
    "frame": line_style,    
    "padding": margins,    
    "alignment": alignment,
    "position": [float, float],
    "scale": float,
    "rotation": float,  +-
    "dpi": float,
    "source_frame": line_style,
    "source_frame_offset": float, Negative decrements
 }
 
 {
    "type" : "break", 
    "value": float, Negative values ​​are allowed
 }
 
 {  
    "type" : "page_break"
 } 
```

Other important information:
If you need a small PDF file size on disk, use light fonts, as they are embedded within the PDF.

Links:

https://github.com/numaelis/genpdf-json-bin

https://github.com/numaelis/genpdf-json-rs

https://gitlab.com/numaelis/pygenpdf