lookup for nested fields

[ArneNostitz]

hi, im currently trying to get a lookup working, where the links are in a nested object list.

how would i need to setup this lookup? thanks!

lookup: project-name

frontmatter:
project
project-name:[[project1]]
date
whatever-key
project-name:[[project2]]
date
whatever-key
project-name:[[project3]]
date
whatever-key

[LynetteCullens]

Right now, my current frontmatter looks like this:

---
fileClass: Variables
mathLink: ${\color{red}a}\left[\pu{m//s2},\pu{cm//s2},\pu{ft//s2} \right]$
mathLink-blocks:
  AltNotation: 
  LinkedDimensions: <span class="center-align"><sup style="font-size:150%;"><span style="font-size:200%;">[</span><span class="frac"><sup>[[Length#^Dimensions]]</sup><span>/</span><sub>[[Time#^Dimensions]]<sup>2</sup></sub></span><span style="font-size:200%;">]</span></span></span>
  LinkedStaticDimensions: 
  MKS: ${\color{red}a}[\pu{m//s2}]$
  CGS: ${\color{red}a}[\pu{cm//s2}]$
  FPS: ${\color{red}a}[\pu{ft//s2}]$
  LinkedFormula: <span class="center-align"><sup style="font-size:150%;">[[Acceleration]] = <span class="frac"><sup>[[Force]]*[[Gravitational Constant]]</sup><span>/</span><sub>[[Mass]]</sub></span></span></span>
  LinkedFormula1: 
  LinkedFormula2: 
  LinkedFormula3: 
  LinkedFormula4: 
  LinkedFormula5: 
  GetLinks: ""
aliases: 
parent: |-
  - "[[Length#^Dimensions]]"
  - "[[Time#^Dimensions]]"
  - "[[Force]]"
  - "[[Gravitational Constant]]"
  - "[[Mass]]"
same: 
Type: Variable

---

This plugin wouldn't work for me, so I downloaded Metaedit and used their API Instead to automatically call my nested links into a parent frontmatter property.

const { update } = app.plugins.plugins["metaedit"].api;
const activeFile = app.workspace.getActiveFile();
const currentTitle = activeFile ? activeFile.basename : "";

// Define fieldsToCheck array as optional, and filter out any potential undefined elements
const fieldsToCheck = [
  "LinkedDimensions",
  "LinkedStaticDimensions",
  "LinkedFormula",
  "LinkedFormula1",
  "LinkedFormula2",
  "LinkedFormula3",
  "LinkedFormula4",
  "LinkedFormula5"
].filter(field => field);

let links = [];

// Check if fieldsToCheck is defined before iterating over it
if (fieldsToCheck) {
  fieldsToCheck.forEach(field => {
    // Use optional chaining to safely access nested properties
    const fieldContent = dv.current().file.frontmatter["mathLink-blocks"]?.[field];
    if (fieldContent) {
      const matches = fieldContent.match(/\[\[([^\]]+)\]\]/g);
      if (matches) links.push(...matches);
    }
  });
}

links = [...new Set(links)].filter(link => link !== '[[Variables]]');

// Filter out links that match the current file's title
links = links.filter(link => !link.includes(currentTitle));

// Format links for output
const formattedLinks = links.map(link => `- "${link}"`).join("\n");

// Update the GetLinks property in the document's frontmatter
const currentFrontmatter = dv.current().file.frontmatter;
currentFrontmatter.GetLinks = formattedLinks;

// Check if any of the specified fields exist before updating
if (fieldsToCheck && Object.keys(currentFrontmatter["mathLink-blocks"] || {}).some(field => fieldsToCheck.includes(field))) {
  await update('parent', formattedLinks, activeFile);
}

If you just want a list, this works

const fields = [
  "LinkedDimensions",
  "LinkedStaticDimensions",
  "LinkedFormula",
  "LinkedFormula1",
  "LinkedFormula2",
  "LinkedFormula3",
  "LinkedFormula4",
  "LinkedFormula5"
];

let links = [];

fields.forEach(field => {
  const content = dv.current().file.frontmatter["mathLink-blocks"][field];
  if (content) {
    const matches = content.match(/\[\[([^\]]+)\]\]/g);
    if (matches) links.push(...matches);
  }
});

links = [...new Set(links)].filter(link => link !== '[[Variables]]');
dv.span(links.map(link => `- "${link}"`).join("\n"));

[ararrocks]

thanks Lynette - but its not quite what i want.

i want to have a lookup field populated with links of files that are related to a project.

usecase:
Contacts are linked to Projects in the way described in post 1.
Project Files have a Lookup called "related-contacts" that is populated with all the relevant contacts links

[LynetteCullens]

I'm not sure what exactly you're trying to do from the explanation given, but if you place this dataviewjs query into the file that you want the links to populate on, then it should work.

const fieldsToCheck is the Object ["parent"] (Note: I changed all of my ObjectLists over to Object because none of my queries worked. This may not affect you, though.)

const fieldValue is the nested ["nested"] field under Object.

The query looks up files that have links to the current file in a specific YAML field.

const fieldsToCheck = ["parent"]; // Specify the fields you want to check for inlinks
const fieldValue = dv.current().file[fieldsToCheck[0]]?.["nested"]; // Initialize fieldValue

let hasRun = false; // Introduce the flag variable

(async () => {
    if (hasRun) { // Check if the flag is set
        return; // Stop if already run
    }

    try {
        const { update } = app.plugins.plugins["metaedit"].api;
        const activeFile = app.workspace.getActiveFile();
        if (!activeFile) {
            new Notice('No active file found.');
            return;
        }

        // Get the currently active file
        const tFile = app.workspace.getActiveFile();
        const fileCache = await app.metadataCache.getFileCache(tFile);

        // Retrieve inlinks from specific fields
        let inlinks = dv.current().file.inlinks || [];
        
        // Check each field in fieldsToCheck
        fieldsToCheck.forEach(field => {
            const fieldValue = dv.current().file[field]?.["ParentVariable"];
            if (fieldValue !== undefined) {
                inlinks = inlinks.concat(fieldValue);
            }
        });

        // Format inlinks as [["LinkTitle"]]
        inlinks = inlinks.map(link => `[[${link.path.split('/').pop().replace('.md', '')}]]`);

        // Always update the Inlinks property in the document's frontmatter
        if (fileCache.frontmatter) {
            fileCache.frontmatter.inlinks = inlinks;
            await update('inlinks', inlinks, tFile); // Use tFile for updating
            new Notice('Inlinks updated successfully');
        }

        hasRun = true; // Set the flag to indicate the code has run
    } catch (error) {
        new Notice(`Uncaught error: ${error.message}`);
    }
})();

Updated Code if you want to check multiple nested fields

const fieldsToCheck = [
    "nested1",
    "nested2"
].filter(field => field);

const fieldValue = fieldsToCheck.length > 0 ? (dv.current().file["ObjectParent"]?.[fieldsToCheck[0]] || []) : []; // Initialize fieldValue using the first field in fieldsToCheck, or empty array if fieldsToCheck is empty or property does not exist

let hasRun = false; // Introduce the flag variable

(async () => {
    if (hasRun) { // Check if the flag is set
        return; // Stop if already run
    }

    try {
        const { update } = app.plugins.plugins["metaedit"].api;
        const activeFile = app.workspace.getActiveFile();
        if (!activeFile) {
            new Notice('No active file found.');
            return;
        }

        // Get the currently active file
        const tFile = app.workspace.getActiveFile();
        const fileCache = await app.metadataCache.getFileCache(tFile);

        let inlinks = dv.current().file.inlinks || [];

        // Ensure mathLink-blocks is defined before accessing its properties
        if (dv.current().file["mathLink-blocks"]) {
            // Iterate through fieldsToCheck and retrieve field values
            fieldsToCheck.forEach(field => {
                const fieldValue = dv.current().file["mathLink-blocks"][field];
                if (fieldValue !== undefined) {
                    inlinks = inlinks.concat(fieldValue);
                }
            });
        }

        // Format inlinks as [["LinkTitle"]]
        inlinks = inlinks.map(link => `[[${link.path.split('/').pop().replace('.md', '')}]]`);

        // Always update the Inlinks property in the document's frontmatter
        if (fileCache.frontmatter) {
            fileCache.frontmatter.inlinks = inlinks;
            await update('inlinks', inlinks, tFile); // Use tFile for updating
            new Notice('Inlinks updated successfully');
        }

        hasRun = true; // Set the flag to indicate the code has run
    } catch (error) {
        new Notice(`Uncaught error: ${error.message}`);
    }
})();

[ararrocks]

wow thanks for this extensive code. i was more wondering if its possible to use a lookup field from metadata menu. and pointing it to a nested field in an objectlist. something in the scope of:

[ararrocks]

where "job" is the parent and "company" is the nested field under job.
i tried job.company, job[].company and just company ... nothing populates

[LynetteCullens]

Nope. I've tried 1,000 different variations, and no query worked for nested fields.