add backlinks to selected linked drafts

script

const backlinkSectionTitle = "backlinks"
addBacklinksToSelectedForwardLinkedDraftsInGivenDraft(draft)

/**
 * add backlinks to selected drafts linked as wiki-style-links in the given draft
 * @param {Draft} d the draft you want to search the outgoing links from
 */
function addBacklinksToSelectedForwardLinkedDraftsInGivenDraft(d){
    const matches = getOutgoingLinksInDraft(d)
    let drafts = getDraftsFromTitles(matches)
    // create map for titles and drafts to be used in prompt
    const titleToDraftMap = new Map();
    drafts.forEach((curDraft) => {  
        titleToDraftMap.set(curDraft.displayTitle,curDraft)
    })

    // create prompt to let user decide which drafts should be linked
    let p = new Prompt()
    p.title = "select drafts"
    p.message = "select the drafts where backlinks should be added"
    p.addSelect("draftsToLink","",Array.from(titleToDraftMap.keys()),[],true);
    p.addButton("add links to drafts")
    if(p.show()){
        let selectedDrafts = p.fieldValues["draftsToLink"]
        selectedDrafts.forEach((dTitle) => {
            insertBacklinkToDestinationDraftFromSourceDraft(d,titleToDraftMap.get(dTitle))
        })
    }
}

/**
 * finds all wiki-style-links in the given draft and returns them
 * @param {Draft} d the Draft where you want to search the outgoing links in
 * @returns array of titles in outgoing links
 */
function getOutgoingLinksInDraft(d){
    let content = d.content
    const regex = /\[\[([^\]]+)\]\]/g;
    const matches = [];

    let match;
    while ((match = regex.exec(content)) !== null) {
        const linkText = match[1];
        if(!matches.includes(linkText) && linkText != draft.displayTitle){
            matches.push(linkText);
        }
    }
    return matches
}

/**
 * finds drafts for each given title
 * @param {String[]} titles array of titles that you want to search drafts for
 * @returns array of Drafts[] (only unique titles are retuned)
 */
function getDraftsFromTitles(titles){
    let drafts = []
    titles.forEach((title) => {
        let foundDrafts = Draft.queryByTitle(title)
        if(foundDrafts.length == 1){
            drafts.push(foundDrafts[0])    
        }
    })
    return drafts
}

/**
 * insert a backlink to the sourceDraft at the linkedDraftsSection in the destinationDraft
 * @param {Draft} sourceDraft the Draft you want to link from
 * @param {Draft} destinationDraft the Draft where you want to insert the link to the sourceDraft
 */
function insertBacklinkToDestinationDraftFromSourceDraft(sourceDraft, destinationDraft) {
    // don't allow linking to the same draft
    if (sourceDraft == destinationDraft) {
        return 0
    }
    let updateNeeded = false
    let linkText = `[[${sourceDraft.displayTitle}]]`
    const backlinkSectionStartingText = `---\n\n## `+ backlinkSectionTitle + `\n\n`
    //check if text is already in given draft d
    if (destinationDraft.content.includes(backlinkSectionStartingText)) {
        // already present, only add link
        // check if link is already exisitng
        let backLinksSectionText = destinationDraft.content.split(backlinkSectionStartingText)[1]
        if (!backLinksSectionText.includes(linkText)) {
            destinationDraft.content = destinationDraft.content.trim() + "\n- " + linkText
            updateNeeded = true
        }
    } else {
        // its the first backlink - add section marker and link
        destinationDraft.content = destinationDraft.content.trim() + "\n\n" + backlinkSectionStartingText + "- " + linkText
        updateNeeded = true
    }
    if(updateNeeded){
    	destinationDraft.update()
    	app.displaySuccessMessage("link added")
    }
}