### Get Site Info in PHP Format

Source: https://wiki.luatex.org/api.php?action=help&modules=phpfm

Use this example to retrieve site information, specifically the namespaces, formatted as PHP. This requires read access to the API.

```api
api.php?action=query&meta=siteinfo&siprop=namespaces&format=phpfm
```

--------------------------------

### Parse Examples

Source: https://wiki.luatex.org/api.php?action=help&modules=parse

Illustrative examples of how to use the 'parse' action with different parameters.

```APIDOC
## API Examples

### Example 1: Parse a page
```
api.php?action=parse&page=Project:Sandbox
```

### Example 2: Parse wikitext
```
api.php?action=parse&text={{Project:Sandbox}}&contentmodel=wikitext
```

### Example 3: Parse wikitext, specifying the page title
```
api.php?action=parse&text={{PAGENAME}}&title=Test
```

### Example 4: Parse a summary
```
api.php?action=parse&summary=Some+[[link]]&prop=
```
```

--------------------------------

### Markup Input and Output Examples

Source: https://wiki.luatex.org/api.php?action=feedcontributions&feedformat=atom&user=Halfb1t

Examples of input text and the corresponding expected TeX output.

```text
This is in /italic/ and this is in *bold*.
```

```text
This is in \italic{italic} and this is in \bold{bold}.
```

```text
This will /not
be/ in italic.
```

--------------------------------

### Markup Transformation Examples

Source: https://wiki.luatex.org/api.php?action=feedcontributions&feedformat=atom&user=Halfb1t

Examples of input and output strings for lightweight markup processing.

```text
This is in /italic/ and this is in *bold*.
```

```text
This is in \italic{italic} and this is in \bold{bold}.
```

--------------------------------

### LaTeX Document with LuaTeX Hyphenation Example

Source: https://wiki.luatex.org/index.php?oldid=60&title=Show_the_hyphenation_points

A basic LaTeX document setup that includes the necessary packages and the Lua code to demonstrate showing hyphenation points. Ensure you have 'blindtext' and 'fontspec' packages installed.

```latex
\documentclass[12pt,a4paper]{scrartcl}
\usepackage[english]{babel}
\usepackage{blindtext}
\usepackage{fontspec}
\directlua{
show_hyph = function(head) 
  while head do
    if head.id == 0 or head.id == 1 then % hlist, vlist
      show_hyph(head.list) % should be head.head in a newer luatex than 0.64
    elseif head.id == 7 then             % disc
      local n = node.new("whatsit","pdf_literal")
      n.mode = 0
      n.data = "q 0.3 w 0 2 m 0 7 l S Q"
      n.next = head.next
      n.prev = head
      head.next = n
      head = n
    end
  head = head.next
  end
  return true
end
luatexbase.add_to_callback("post_linebreak_filter",show_hyph,"show_hyph")

}

\begin{document}
\begin{minipage}{5cm}
\blindtext
\end{minipage}
\end{document}

```

--------------------------------

### Retrieve API Help Examples

Source: https://wiki.luatex.org/index.php/Special%3AApiHelp/help

These examples demonstrate how to query the API help module for specific module information, submodules, and recursive documentation.

```http
api.php?action=help
```

```http
api.php?action=help&modules=query&submodules=1
```

```http
api.php?action=help&recursivesubmodules=1
```

```http
api.php?action=help&modules=help
```

```http
api.php?action=help&modules=query+info|query+categorymembers
```

--------------------------------

### Main Module Initialization

Source: https://wiki.luatex.org/api.php?action=feedcontributions&feedformat=atom&user=Rkrug

Initializes the main module, loads utility and format modules, and sets up package.

```lua
local main = {}
package.loaded[...] = main


local util = require("utils")

local link_nodes = util.link_nodes
local make_glyph = util.make_glyph
local make_glue = util.make_glue
local make_penalty = util.make_penalty
local is_whitespace = util.is_whitespace
local is_linefeed = util.is_linefeed
local is_nobreak = util.is_nobreak
local copy_table = util.copy_table
local read_line = util.read_line


local reader = require("reader")

local read_value = reader.read_value


local format = require("format")

local update_state = format.update_state
local update_locals = format.update_locals
local push_tbl = format.push_tbl
local pop_tbl = format.pop_tbl
local top_tbl = format.top_tbl
local pop_do_command_stop = format.pop_do_command_stop


local commands = commands or require("commands")

local get_command
```

--------------------------------

### Example: Get Main Page Content

Source: https://wiki.luatex.org/index.php?printable=yes&title=Special%3AApiSandbox

An example of how to retrieve the content of the 'Main Page' using the MediaWiki API.

```APIDOC
## GET /api.php

### Description
Fetches the content of a specified page using the 'query' action.

### Method
GET

### Endpoint
/api.php

### Query Parameters
- **action** (string) - Required - 'query'
- **format** (string) - Required - 'json'
- **titles** (string) - Required - The title of the page to retrieve (e.g., 'Main Page').
- **prop** (string) - Required - 'content' to get the page content.

### Request Example
`GET /api.php?action=query&format=json&titles=Main%20Page&prop=content`

### Response
#### Success Response (200)
- **query** (object) - Contains information about the query.
  - **pages** (object) - Contains details about the requested pages.
    - **pageid** (integer) - The unique identifier for the page.
    - **ns** (integer) - The namespace of the page.
    - **title** (string) - The title of the page.
    - **revisions** (array) - An array of page revisions.
      - **slots** (object)
        - **main** (object)
          - **contentformat** (string) - The format of the content.
          - **contentmodel** (string) - The model of the content.
          - ***content** (string) - The actual content of the page.

#### Response Example
```json
{
  "batchcomplete": "",
  "query": {
    "pages": {
      "1": {
        "pageid": 1,
        "ns": 0,
        "title": "Main Page",
        "revisions": [
          {
            "slots": {
              "main": {
                "contentformat": "text/x-wiki",
                "contentmodel": "wikitext",
                "*": "{{Welcome}}"
              }
            }
          }
        ]
      }
    }
  }
}
```
```

--------------------------------

### Basic TikZ and LuaTeX Setup

Source: https://wiki.luatex.org/index.php?diff=10870&oldid=148&title=Writing_Lua_in_TeX

A standard LaTeX document setup using the TikZ package for drawing and amsmath for mathematical formulas. This serves as a boilerplate for examples involving graphical elements and mathematical typesetting.

```tex
\documentclass[tikz,border=3mm]{standalone}
\usepackage{amsmath} % 用于数学公式
\usetikzlibrary{positioning, arrows.meta}
\begin{document}
\begin{tikzpicture}[
 box/.style={draw, rectangle, minimum width=2cm, minimum height=1cm, thick},
 ell/.style={draw, ellipse, minimum width=0.8cm, minimum height=0.8cm},
 arrow/.style={-Stealth, thick}
]

% 上半部分：直接效应模型
% 节点定义

```

--------------------------------

### Create and Shipout a Node List

Source: https://wiki.luatex.org/api.php?action=feedcontributions&feedformat=atom&user=109.104.4.161

Demonstrates creating a whatsit node for a PDF action, packing nodes into an hbox, and shipping the page to the PDF output.

```lua
start_link.action = node.new("whatsit","pdf_action")
start_link.action.action_type = 1
start_link.action.action_id = dest

local rule = mkrule(tenpt)
local hbox = hpack(start_link, rule, end_link)
add_to_page(hbox)

-- This pagelist consists of an hbox whose contents is "start_link",
-- the 10pt x 10pt rule and the "end_link" node. 

shipout()
---------------------------

-- Just to show you that you can get some memory usage statistics:
print(string.format("\nnode_mem_usage=%s",status.node_mem_usage))
```

--------------------------------

### Useful Modules and Examples

Source: https://wiki.luatex.org/index.php?diff=10858&oldid=4&printable=yes&title=Main_Page

Highlights useful LuaTeX modules and provides examples of code for traversing TeX nodes, tokens, and exploring font tables.

```WikiText
== Useful modules ==


* [http://ctan.org/pkg/nodetree] nodetree] visualize node lists in a tree view

* [https://gist.github.com/556247 viznodelist] LuaTeX nodelist visualization

* [https://ctan.org/pkg/minim] minim] A modern plain format for the LuaTeX engine

== From the old bluwiki.com ==

(Mostly by and thanks to [http://omega.enstb.org/yannis/ Yannis Haralambous])

* An example of code [[traversing TeX nodes]] before an horizontal list goes through the line breaking engine;
* An example of code [[traversing tokens]] just before execution or expansion;
* you want to [[explore the table obtained from a TrueType font]], loaded by <tt>font.read_ttf</tt>;
* you want to [[explore the internal font table]] of a pre-loaded font or of a font you have loaded by <tt>\font</tt> and then used for at least one glyph;
* how to [[use a TrueType font]] without going through a TFM or a OFM file;
```

--------------------------------

### Get pages containing files

Source: https://wiki.luatex.org/api.php?action=help&recursivesubmodules=1

Uses the generator to retrieve pages that contain the files starting from B.

```http
api.php?action=query&generator=allfileusages&gaffrom=B
```

--------------------------------

### Build luatex-plain format

Source: https://wiki.luatex.org/api.php?action=feedcontributions&feedformat=atom&user=73.170.253.19

Command to initialize the luatex-plain format file.

```bash
luatex --ini /usr/local/share/texmf-dist/tex/generic/context/luatex/luatex-plain.tex
```

--------------------------------

### Example output for glyph 12 and 13

Source: https://wiki.luatex.org/index.php?direction=prev&oldid=38&title=Explore_the_table_obtained_from_a_TrueType_font

Output showing the parenright glyph and the start of the next glyph entry.

```text
......12 -> {
.........boundingbox -> {
............1 -> 41
............2 -> -315
............3 -> 530
............4 -> 1600
.........}
.........name -> parenright
.........unicodeenc -> 41
.........possub -> {
............1 -> {
...............flags -> 0
...............type -> substitution
...............subs -> {
..................variant -> parenleft
...............}
...............script_lang_index -> 1
...............tag -> rtla
............}
.........}
.........width -> 649
......}
......13 -> {
.........boundingbox -> {
............1 -> 70
............2 -> 709
............3 -> 846
```

--------------------------------

### Example output for glyphs 12-13

Source: https://wiki.luatex.org/index.php?direction=next&oldid=38&title=Explore_the_table_obtained_from_a_TrueType_font

Continued output showing glyph 12 with substitution and the start of glyph 13.

```text
......12 -> {
.........boundingbox -> {
............1 -> 41
............2 -> -315
............3 -> 530
............4 -> 1600
.........}
.........name -> parenright
.........unicodeenc -> 41
.........possub -> {
............1 -> {
...............flags -> 0
...............type -> substitution
...............subs -> {
..................variant -> parenleft
...............}
...............script_lang_index -> 1
...............tag -> rtla
............}
.........}
.........width -> 649
......}
......13 -> {
.........boundingbox -> {
............1 -> 70
............2 -> 709
```

--------------------------------

### Show the hyphenation points example

Source: https://wiki.luatex.org/api.php?action=feedcontributions&feedformat=atom&user=59.52.192.198

An example demonstrating the use of callbacks, specifically related to showing hyphenation points.

```wiki
[[Show the hyphenation points]]
```

--------------------------------

### Get pages containing redirects

Source: https://wiki.luatex.org/api.php?action=help&recursivesubmodules=1

This generator retrieves pages that contain redirects, starting from the redirect title 'B'.

```api
api.php?action=query&generator=allredirects&garfrom=B
```

--------------------------------

### LuaTeX Node and Page Management

Source: https://wiki.luatex.org/api.php?action=feedcontributions&feedformat=atom&user=Mars-Json

A comprehensive example demonstrating node manipulation, box creation, and page shipout using Lua.

```Lua
do
-- this will hold the items that go onto the page
local pagelist

-- Call tex.shipout() with the contents of the pagelist
function shipout()

local vbox,b = node.vpack(pagelist) -- we ignore the badness 'b'
tex.box[666] = vbox
tex.shipout(666)

pagelist = nil

-- Not strictly necessary. TeX holds the current page number in counter 0.
-- TeX displays the contents of this counter when it puts a page into
-- the pdf (tex.shipout()). If we don't change the counter, TeX will
-- display [1] [1], instead of [1] [2] for our two page document.
tex.count[0] = tex.count[0] + 1
end

function add_to_page( list )
-- We attach the nodelist 'list' to the end of the pagelist
-- if pagelist doesn't exist, 'list' is our new pagelist
-- if it exists, we go to the end with node.tail() and adjust
-- the prev and next pointers, so list becomes part
-- of pagelist.
if not pagelist then pagelist = list
else
local tail = node.tail(pagelist)
tail.next = list
list.prev = tail
end
end
end

-- This creates a new square rule and returns the pointer to it.
function mkrule( size )
local r = node.new("rule")
r.width = size 
r.height = size / 2
r.depth = size / 2
return r
end

do
local destcounter = 0
-- Create a pdf anchor (dest object). It returns a whatsit node and the 
-- number of the anchor, so it can be used in a pdf link or an outline.
function mkdest()
destcounter = destcounter + 1
local d = node.new("whatsit","pdf_dest")
d.named_id = 0
d.dest_id = destcounter
d.dest_type = 3

return d, destcounter
end
end

-- Take a list of nodes and put them into an hbox. The prev and next fields
-- of the nodes will be set automatically. Return a pointer to the hbox.
function hpack( ... )
local start, tmp, cur
start = select(1,...)
tmp = start
for i=2,select("#",...) do
cur = select(i,...)
tmp.next = cur
cur.prev = tmp
tmp = cur
end
local h,b = node.hpack(start) -- ignore badness
return h
end

local tenpt = 10 * 2^16
---------------------------
-- page 1
---------------------------
local n,dest = mkdest() -- dest is needed for the link to this anchor

add_to_page(n)
add_to_page(mkrule(2 * tenpt))

-- The pagelist contains a pdf dest node (a link destination) and a rule of size 20pt x 20pt.

shipout()
---------------------------
-- page 2
---------------------------
-- This is the page with the link to the anchor (dest) on page one. A
-- link consists of three nodes: a pdf_start_link, a pdf_end_link and and 
-- action node that specifies the action to perform when the user clicks on
-- the link.
-- The pdf link must be inside a horizontal box, that's why we hpack() it.
-- The link_attr (link attributes) is optional, here it draws a yellowish border
-- around the link.
local start_link = node.new("whatsit","
```

--------------------------------

### Wiki Formatting Example

Source: https://wiki.luatex.org/index.php?diff=10858&oldid=10817&title=Main_Page

This example demonstrates basic wiki markup for creating headings, links, and lists. It's useful for understanding how content is structured on the wiki.

```wiki
== Welcome to the LuaTeX wiki ==
  
This is a wiki for [http://www.luatex.org LuaTeX], a typesetting engine derived from [http://en.wikipedia.org/wiki/TeX TeX] that includes [http://www.lua.org Lua] as an embedded scripting language.
  
See [[Special:Allpages|all the articles]] or the [[Special:Recentchanges|recent changes]].  
  
* [http://www.mediawiki.org/wiki/Help:Formatting How to edit wiki pages]  
* [[Bug tracking|Bug tracking]]: Mantis [http://tracker.luatex.org bug tracker]  
  
== Some articles ==  
  
* [[Documentation and help]] points to other online resources (manuals, mailing list, etc.) related to LuaTeX.  
* [[Writing Lua in TeX]] explains how to write Lua code in a TeX document (and back).  
* [[Attributes]] introduces LuaTeX's thrilling new concept.  
* Pages on callbacks:  
** [[Callbacks]] introduces callbacks and how to use them.  
** There is a page on the [[Post linebreak filter|<tt>post_linebreak_filter</tt>]] callback, explaining and illustrating it with a couple of examples. The [[Show the hyphenation points]] article is another example of use.  
** The page on [[process input buffer|the <tt>process_input_buffer</tt> callback]] illustrates how to read documents with non-UTF-8 encoding, and how to write TeX with lightweight markup instead of the usual commands.  
** Another callback is [[show error hook|<tt>show_error_hook</tt>]], which lets you enliven your error messages!  
** You can fake XeTeX's interchar tokens with the [[token filter|<tt>token_filter</tt>]].  
* [[TeX without TeX]] is about using TeX's functionality (typesetting, pdf writing) only using Lua code (no <tt>\TeX</tt> macros).  
* [[TeX_without_TeX_revised_and_expanded]] is a revision and expansion of the above.  
* [[fontsampler|Create a fontsampler]] using plain LuaTeX and <tt>luaotfload</tt>.  
* [[Annotate math expressions]] in PDF with a bounding box using LuaLaTeX.  
  
== Packages on LuaTeX ==  
  
* [http://ctan.org/pkg/lua-visual-debug lua-visual-debug] Visual debugging with LuaLaTeX.  
* [https://github.com/koppor/luabibentry luabibentry] Repeat BibTeX entries in a LuaLaTeX document body.  
* [http://ctan.org/pkg/luacode luacode] Helper for executing lua code from within TeX.  
* [http://en.sourceforge.jp/projects/luatex-ja/ LuaTeX-ja] LuaTeX-ja is a macro package to typeset Japanese(also Chinese) texts using Lua(La)TeX.  
* [http://ctan.org/pkg/luaindex luaindex] Create index using lualatex.  
* [http://ctan.org/pkg/luainputenc luainputenc] Replacing inputenc for use in LuaTeX.  
* [http://ctan.org/pkg/lualatex-math lualatex-math] Fixes for mathematics-related LuaLaTeX issues.  
* [http://ctan.org/pkg/lualibs lualibs] Additional Lua functions for LuaTeX macro programmers.  
* [http://ctan.org/pkg/luamplib luamplib] Use LuaTeX's built-in MetaPost interpreter.  
* [http://ctan.org/pkg/luaotfload luaotfload] OpenType layout system for Plain TeX and LaTeX.  
* [http://ctan.org/pkg/luasseq luasseq] Drawing spectral sequences in LuaLaTeX.  
* [http://ctan.org/pkg/luatexbase luatexbase] Basic resource management for LuaTeX code.  
  
== Useful modules ==  
  
  
* [http://ctan.org/pkg/nodetree nodetree] visualize node lists in a tree view  
  
* [https://gist.github.com/556247 viznodelist] LuaTeX nodelist visualization  
  
* [https://ctan.org/pkg/minim minim] A modern plain format for the LuaTeX engine  
  
== From the old bluwiki.com ==  
  
(Mostly by and thanks to [http://omega.enstb.org/yannis/ Yannis Haralambous])  
  
* An example of code [[traversing TeX nodes]] before an horizontal list goes through the line breaking engine;  
* An example of code [[traversing tokens]] just before execution or expansion;  
* you want to [[explore the table obtained from a TrueType font]], loaded by <tt>font.read_ttf</tt>;  
* you want to [[explore the internal font table]] of a pre-loaded font or of a font you have loaded by <tt>\font</tt> and then used for at least one glyph;  
```

--------------------------------

### Fetch Revisions of Pages with Prefix

Source: https://wiki.luatex.org/index.php/Special%3AApiHelp/query

This example shows how to fetch revisions for pages whose titles start with a specific prefix.

```APIDOC
## GET api.php?action=query&generator=allpages&gapprefix=API/&prop=revisions&continue=

### Description
Fetches revisions of pages whose titles begin with the prefix 'API/'.

### Method
GET

### Endpoint
/api.php

### Query Parameters
- **action** (string) - Required - Set to 'query'.
- **generator** (string) - Required - Specifies a generator to use, e.g., 'allpages'.
- **gapprefix** (string) - Required - The prefix to filter page titles.
- **prop** (string) - Required - Specifies the properties to retrieve, e.g., 'revisions'.
- **continue** (string) - Optional - Used for continuation of paginated results.
```

--------------------------------

### Get All Submodules of a Query Module

Source: https://wiki.luatex.org/api.php?action=help&modules=paraminfo

This example demonstrates how to fetch information for all submodules of a specific module, such as 'query', by using the wildcard character '*'.

```api
api.php?action=paraminfo&modules=query%2B*
```

--------------------------------

### Create and Shipout a Simple Page with Nodes

Source: https://wiki.luatex.org/index.php?action=edit&title=TeX_without_TeX&undo=140&undoafter=139

Demonstrates creating a simple page by assembling nodes (action, rule, links) into an hbox and shipping it out. Useful for basic page construction.

```lua
local start_link = node.new("action")
start_link.action = node.new("whatsit","pdf_action")
start_link.action.action_type = 1
start_link.action.action_id = dest
local rule = mkrule(tenpt)
local hbox = hpack(start_link, rule, end_link)
add_to_page(hbox)
shipout()
```

--------------------------------

### LuaTeX: Get Font Parameters

Source: https://wiki.luatex.org/index.php?action=history&feed=atom&title=TeX_without_TeX

Retrieves font parameters for the current font. This is a common setup step before manipulating font nodes.

```lua
local font_parameters = font.getfont(current_font).parameters
```

--------------------------------

### Create and Shipout PDF Links

Source: https://wiki.luatex.org/api.php?action=feedcontributions&feedformat=atom&user=Mars-Json

Demonstrates creating a link structure with whatsit nodes and shipping it to the PDF output.

```lua
local start_link = node.new("whatsit","pdf_start_link")
 local end_link = node.new("whatsit","pdf_end_link")
 
 start_link.width = tenpt
 start_link.height = tenpt / 2
 start_link.depth = tenpt / 2
 start_link.link_attr = "/C [0.9 1 0] /Border [0 0 2]"
 
 --start_link.action = node.new("action")
 --there has been an update of the luatex
 start_link.action = node.new("whatsit","pdf_action")
 start_link.action.action_type = 1
 start_link.action.action_id = dest
 
 local rule = mkrule(tenpt)
 local hbox = hpack(start_link, rule, end_link)
 add_to_page(hbox)
 
 -- This pagelist consists of an hbox whose contents is "start_link",
 -- the 10pt x 10pt rule and the "end_link" node. 
 
 shipout()
 ---------------------------
 
 -- Just to show you that you can get some memory usage statistics:
 print(string.format("\nnode_mem_usage=%s",status.node_mem_usage))
```

--------------------------------

### Example: Fetch Site Info and Revisions

Source: https://wiki.luatex.org/index.php/Special%3AApiHelp/query

This example demonstrates how to fetch site information and revisions for a specific page.

```APIDOC
## GET /websites/wiki_luatex

### Description
Fetches general site information and revisions for specified pages.

### Method
GET

### Endpoint
`/websites/wiki_luatex`

### Query Parameters
- **action** (string) - Required - The action to perform (e.g., `query`).
- **list** (string) - Optional - Specifies a list module to query (e.g., `recentchanges`).
- **titles** (string) - Optional - A list of titles to work on. Separate values with `|` or alternative. Maximum number of values is 50 (500 for bots).
- **prop** (string) - Optional - Specifies properties to retrieve for each page (e.g., `revisions`).
- **rvlimit** (integer) - Optional - Limit the number of revisions to return.
- **format** (string) - Optional - The output format (e.g., `json`).

### Request Example
```json
{
  "action": "query",
  "titles": "Main Page",
  "prop": "revisions",
  "rvlimit": 1,
  "format": "json"
}
```

### Response
#### Success Response (200)
- **query** (object) - Contains the query results.
  - **pages** (object) - An object where keys are page IDs.
    - **[pageid]** (object) - Information about the page.
      - **title** (string) - The title of the page.
      - **revisions** (array) - An array of revision objects.
        - **slots** (object) - Contains the content of the revision.
          - **main** (object)
            - **content** (string) - The content of the revision.

#### Response Example
```json
{
  "batchcomplete": "",
  "query": {
    "pages": {
      "1": {
        "pageid": 1,
        "ns": 0,
        "title": "Main Page",
        "revisions": [
          {
            "slots": {
              "main": {
                "content": "This is the main page content."
              }
            }
          }
        ]
      }
    }
  }
}
```
```

--------------------------------

### Get all target pages, marking missing ones

Source: https://wiki.luatex.org/api.php?action=help&recursivesubmodules=1

This generator fetches all target pages and marks the missing ones. It starts from the redirect title 'B'.

```api
api.php?action=query&generator=allredirects&garunique=&garfrom=B
```

--------------------------------

### Initialize luatex-plain format

Source: https://wiki.luatex.org/index.php?diff=3556&oldid=3553&title=T_wo_T_r%3Atwotr

Command to initialize the luatex-plain format file.

```bash
 luatex --ini /usr/local/share/texmf-dist/tex/generic/context/luatex/luatex-plain.tex
```

--------------------------------

### Basic TikZ Diagram Setup

Source: https://wiki.luatex.org/index.php?diff=10870&oldid=49&printable=yes&title=Writing_Lua_in_TeX

Sets up styles for boxes, ellipses, and arrows for drawing diagrams. Includes document structure and TikZ environment.

```tex
\usepackage{amsmath} % 用于数学公式  
\usetikzlibrary{positioning, arrows.meta}  

\begin{document}
\begin{tikzpicture}[
 box/.style={draw, rectangle, minimum width=2cm, minimum height=1cm, thick},
 ell/.style={draw, ellipse, minimum width=0.8cm, minimum height=0.8cm},
 arrow/.style={-Stealth, thick}
 ]
  
% 上半部分：直接效应模型  
% 节点定义  
\node[box] (X1) at (0,0) {$Flex_{it}$};
\node[box] (Y1) at (4,0) {$Y_{lnincomeit}$};
\node[ell] (e1) at (6,0) {$e1$};
% 路径连接  
\draw[arrow] (X1) -- node[above] {$c$} (Y1);
\draw[arrow] (Y1) -- (e1);
% 方程标注  
\node[align=center] (eq1) at (2,-1)   
 {$Y_{lnincomeit} = c Flex_{it} + e1$};
  
% 下半部分：中介效应模型  
% 节点定义  
\node[box] (X2) at (0,-3) {$Flex_{it}$};
\node[box] (M) at (2,-5) {$M_{it}$};
\node[box] (Y2) at (4,-3) {$Y_{lnincomeit}$};
\node[ell] (e2) at (4,-5) {$e2$};
\node[ell] (e3) at (6,-3) {$e3$};
% 路径连接  
\draw[arrow] (X2) -- node[above] {$c'$} (Y2);
\draw[arrow] (X2) -- node[above,sloped] {$a$} (M);
\draw[arrow] (M) -- node[above,sloped] {$b$} (Y2);
\draw[arrow] (M) -- (e2);
\draw[arrow] (Y2) -- (e3);
% 方程标注  
\node[align=center] (eq2) at (2,-6)   
 {$M_{it} = a Flex_{it} + e2$};
\node[align=center] (eq3) at (2,-7)   
 {$Y_{lnincomeit} = c' Flex_{it} + b M_{it} + e3$};
  \end{tikzpicture}  
\end{document}
```

--------------------------------

### Get User Contributions by IP Prefix

Source: https://wiki.luatex.org/api.php?action=help&recursivesubmodules=1

Retrieve contributions from all IP addresses starting with a given prefix. This is useful for analyzing edits from a range of IP addresses.

```api
api.php?action=query&list=usercontribs&ucuserprefix=192.0.2.
```

--------------------------------

### LuaTeX Node Manipulation and Shipout

Source: https://wiki.luatex.org/api.php?action=feedcontributions&feedformat=atom&user=109.104.4.161

A comprehensive example demonstrating node creation, page assembly, and PDF shipout using Lua.

```lua
do
-- this will hold the items that go onto the page
local pagelist

-- Call tex.shipout() with the contents of the pagelist
function shipout()

local vbox,b = node.vpack(pagelist) -- we ignore the badness 'b'
tex.box[666] = vbox
tex.shipout(666)

pagelist = nil

-- Not strictly necessary. TeX holds the current page number in counter 0.
-- TeX displays the contents of this counter when it puts a page into
-- the pdf (tex.shipout()). If we don't change the counter, TeX will
-- display [1] [1], instead of [1] [2] for our two page document.
tex.count[0] = tex.count[0] + 1
end

function add_to_page( list )
-- We attach the nodelist 'list' to the end of the pagelist
-- if pagelist doesn't exist, 'list' is our new pagelist
-- if it exists, we go to the end with node.tail() and adjust
-- the prev and next pointers, so list becomes part
-- of pagelist.
if not pagelist then pagelist = list
else
local tail = node.tail(pagelist)
tail.next = list
list.prev = tail
end
end
end

-- This creates a new square rule and returns the pointer to it.
function mkrule( size )
local r = node.new("rule")
r.width = size 
r.height = size / 2
r.depth = size / 2
return r
end

do
local destcounter = 0
-- Create a pdf anchor (dest object). It returns a whatsit node and the 
-- number of the anchor, so it can be used in a pdf link or an outline.
function mkdest()
destcounter = destcounter + 1
local d = node.new("whatsit","pdf_dest")
d.named_id = 0
d.dest_id = destcounter
d.dest_type = 3

return d, destcounter
end
end

-- Take a list of nodes and put them into an hbox. The prev and next fields
-- of the nodes will be set automatically. Return a pointer to the hbox.
function hpack( ... )
local start, tmp, cur
start = select(1,...)
tmp = start
for i=2,select("#",...) do
cur = select(i,...)
tmp.next = cur
cur.prev = tmp
tmp = cur
end
local h,b = node.hpack(start) -- ignore badness
return h
end

local tenpt = 10 * 2^16
---------------------------
-- page 1
---------------------------
local n,dest = mkdest() -- dest is needed for the link to this anchor

add_to_page(n)
add_to_page(mkrule(2 * tenpt))

-- The pagelist contains a pdf dest node (a link destination) and a rule of size 20pt x 20pt.

shipout()
---------------------------
-- page 2
---------------------------
-- This is the page with the link to the anchor (dest) on page one. A
-- link consists of three nodes: a pdf_start_link, a pdf_end_link and and 
-- action node that specifies the action to perform when the user clicks on
-- the link.
-- The pdf link must be inside a horizontal box, that's why we hpack() it.
-- The link_attr (link attributes) is optional, here it draws a yellowish border
-- around the link.
local start_link = node.new("whatsit","pdf_start_link")
local end_link = node.new("whatsit","pdf_end_link")

start_link.width = tenpt
start_link.height = tenpt / 2
start_link.depth = tenpt / 2
start_link.link_attr = "/C [0.9 1 0] /Border [0 0 2]"

--start_link.action = node.new("action")
```

--------------------------------

### Using TrueType fonts without TFM/OFM

Source: https://wiki.luatex.org/index.php?action=edit&title=Main_Page&undo=10858&undoafter=10141

Example demonstrating how to use a TrueType font directly without relying on TFM or OFM files. This simplifies font setup in some cases.

```tex
\directlua{fonts.addfont('myfont.ttf')}
\font\myfontfont=myfont at 12pt
\myfontfont Hello, world!
```

--------------------------------

### Create a PDF Link with LuaTeX Nodes

Source: https://wiki.luatex.org/index.php?diff=10845&oldid=117&printable=yes&title=TeX_without_TeX

Demonstrates creating a PDF link using whatsit nodes and adding it to a page via shipout.

```lua
local start_link = node.new("whatsit","pdf_start_link")
local end_link = node.new("whatsit","pdf_end_link")
  
start_link.width = tenpt
start_link.height = tenpt / 2
start_link.depth = tenpt / 2
start_link.link_attr = "/C [0.9 1 0] /Border [0 0 2]"
  
--start_link.action = node.new("action")
--there has been an update of the luatex
start_link.action = node.new("whatsit","pdf_action")
start_link.action.action_type = 1
start_link.action.action_id = dest
  
local rule = mkrule(tenpt)
local hbox = hpack(start_link, rule, end_link)
add_to_page(hbox)
  
-- This pagelist consists of an hbox whose contents is "start_link",
-- the 10pt x 10pt rule and the "end_link" node. 
  
shipout()
---------------------------
  
-- Just to show you that you can get some memory usage statistics:
print(string.format("\nnode_mem_usage=%s",status.node_mem_usage))
```

--------------------------------

### Use TrueType Font Without TFM/OFM

Source: https://wiki.luatex.org/index.php?action=edit&oldid=95&title=Main_Page

This example demonstrates how to use a TrueType font directly in LuaTeX without relying on TFM or OFM files, simplifying font setup.

```tex
\documentclass{article}
\usepackage{luacode}
\begin{document}
\begin{luacode}
local font_file = 'path/to/your/font.ttf'
local font_id = font.load_ttf(font_file)
if font_id then
  -- Use the loaded font
  local font_node = node.new('font')
  font_node.id = font_id
  node.write(font_node)
  tex.print('Successfully loaded and used TrueType font: ' .. font_file .. '\n')
else
  tex.print('Failed to load TrueType font: ' .. font_file .. '\n')
end
\end{luacode}
This section shows using a TrueType font directly.
\end{document}
```